Merge commit '3c650efb81aaa3b395ba4606ee68a47ee4efb57b'
[ffmpeg.git] / libavcodec / mpeg12.c
index dc26453..27d680f 100644 (file)
 
 #define UNCHECKED_BITSTREAM_READER 1
 
-//#define DEBUG
-#include "internal.h"
-#include "avcodec.h"
-#include "dsputil.h"
-#include "mpegvideo.h"
+#include "libavutil/attributes.h"
 #include "libavutil/avassert.h"
 #include "libavutil/timecode.h"
 
+#include "internal.h"
+#include "avcodec.h"
+#include "mpegvideo.h"
+#include "error_resilience.h"
 #include "mpeg12.h"
 #include "mpeg12data.h"
-#include "mpeg12decdata.h"
 #include "bytestream.h"
 #include "vdpau_internal.h"
-#include "xvmc_internal.h"
 #include "thread.h"
 
+uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
 
-#define MV_VLC_BITS 9
-#define MBINCR_VLC_BITS 9
-#define MB_PAT_VLC_BITS 9
-#define MB_PTYPE_VLC_BITS 6
-#define MB_BTYPE_VLC_BITS 6
-
-static VLC mv_vlc;
-
-/* as H.263, but only 17 codes */
-static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
-{
-    int code, sign, val, shift;
-
-    code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
-    if (code == 0) {
-        return pred;
-    }
-    if (code < 0) {
-        return 0xffff;
-    }
-
-    sign  = get_bits1(&s->gb);
-    shift = fcode - 1;
-    val   = code;
-    if (shift) {
-        val  = (val - 1) << shift;
-        val |= get_bits(&s->gb, shift);
-        val++;
-    }
-    if (sign)
-        val = -val;
-    val += pred;
-
-    /* modulo decoding */
-    return sign_extend(val, 5 + shift);
-}
-
-static inline int mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n)
-{
-    int level, dc, diff, i, j, run;
-    int component;
-    RLTable *rl = &ff_rl_mpeg1;
-    uint8_t * const scantable    = s->intra_scantable.permutated;
-    const uint16_t *quant_matrix = s->intra_matrix;
-    const int qscale             = s->qscale;
-
-    /* DC coefficient */
-    component = (n <= 3 ? 0 : n - 4 + 1);
-    diff = decode_dc(&s->gb, component);
-    if (diff >= 0xffff)
-        return -1;
-    dc  = s->last_dc[component];
-    dc += diff;
-    s->last_dc[component] = dc;
-    block[0] = dc * quant_matrix[0];
-    av_dlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
-    i = 0;
-    {
-        OPEN_READER(re, &s->gb);
-        /* now quantify & encode AC coefficients */
-        for (;;) {
-            UPDATE_CACHE(re, &s->gb);
-            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-            if (level == 127) {
-                break;
-            } else if (level != 0) {
-                i += run;
-                j = scantable[i];
-                level = (level * qscale * quant_matrix[j]) >> 4;
-                level = (level - 1) | 1;
-                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-                LAST_SKIP_BITS(re, &s->gb, 1);
-            } else {
-                /* escape */
-                run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
-                UPDATE_CACHE(re, &s->gb);
-                level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
-                if (level == -128) {
-                    level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
-                } else if (level == 0) {
-                    level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
-                }
-                i += run;
-                j = scantable[i];
-                if (level < 0) {
-                    level = -level;
-                    level = (level * qscale * quant_matrix[j]) >> 4;
-                    level = (level - 1) | 1;
-                    level = -level;
-                } else {
-                    level = (level * qscale * quant_matrix[j]) >> 4;
-                    level = (level - 1) | 1;
-                }
-            }
-            if (i > 63) {
-                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
-            }
-
-            block[j] = level;
-        }
-        CLOSE_READER(re, &s->gb);
-    }
-    s->block_last_index[n] = i;
-   return 0;
-}
-
-int ff_mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n)
-{
-    return mpeg1_decode_block_intra(s, block, n);
-}
-
-static inline int mpeg1_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
-{
-    int level, i, j, run;
-    RLTable *rl = &ff_rl_mpeg1;
-    uint8_t * const scantable    = s->intra_scantable.permutated;
-    const uint16_t *quant_matrix = s->inter_matrix;
-    const int qscale             = s->qscale;
-
-    {
-        OPEN_READER(re, &s->gb);
-        i = -1;
-        // special case for first coefficient, no need to add second VLC table
-        UPDATE_CACHE(re, &s->gb);
-        if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
-            level = (3 * qscale * quant_matrix[0]) >> 5;
-            level = (level - 1) | 1;
-            if (GET_CACHE(re, &s->gb) & 0x40000000)
-                level = -level;
-            block[0] = level;
-            i++;
-            SKIP_BITS(re, &s->gb, 2);
-            if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-                goto end;
-        }
-        /* now quantify & encode AC coefficients */
-        for (;;) {
-            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-            if (level != 0) {
-                i += run;
-                j = scantable[i];
-                level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
-                level = (level - 1) | 1;
-                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-                SKIP_BITS(re, &s->gb, 1);
-            } else {
-                /* escape */
-                run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
-                UPDATE_CACHE(re, &s->gb);
-                level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
-                if (level == -128) {
-                    level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
-                } else if (level == 0) {
-                    level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
-                }
-                i += run;
-                j = scantable[i];
-                if (level < 0) {
-                    level = -level;
-                    level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
-                    level = (level - 1) | 1;
-                    level = -level;
-                } else {
-                    level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
-                    level = (level - 1) | 1;
-                }
-            }
-            if (i > 63) {
-                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
-            }
-
-            block[j] = level;
-            if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-                break;
-            UPDATE_CACHE(re, &s->gb);
-        }
-end:
-        LAST_SKIP_BITS(re, &s->gb, 2);
-        CLOSE_READER(re, &s->gb);
-    }
-    s->block_last_index[n] = i;
-    return 0;
-}
-
-static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
-{
-    int level, i, j, run;
-    RLTable *rl = &ff_rl_mpeg1;
-    uint8_t * const scantable = s->intra_scantable.permutated;
-    const int qscale          = s->qscale;
-
-    {
-        OPEN_READER(re, &s->gb);
-        i = -1;
-        // special case for first coefficient, no need to add second VLC table
-        UPDATE_CACHE(re, &s->gb);
-        if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
-            level = (3 * qscale) >> 1;
-            level = (level - 1) | 1;
-            if (GET_CACHE(re, &s->gb) & 0x40000000)
-                level = -level;
-            block[0] = level;
-            i++;
-            SKIP_BITS(re, &s->gb, 2);
-            if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-                goto end;
-        }
-
-        /* now quantify & encode AC coefficients */
-        for (;;) {
-            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-            if (level != 0) {
-                i += run;
-                j = scantable[i];
-                level = ((level * 2 + 1) * qscale) >> 1;
-                level = (level - 1) | 1;
-                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-                SKIP_BITS(re, &s->gb, 1);
-            } else {
-                /* escape */
-                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
-                UPDATE_CACHE(re, &s->gb);
-                level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
-                if (level == -128) {
-                    level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
-                } else if (level == 0) {
-                    level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
-                }
-                i += run;
-                j = scantable[i];
-                if (level < 0) {
-                    level = -level;
-                    level = ((level * 2 + 1) * qscale) >> 1;
-                    level = (level - 1) | 1;
-                    level = -level;
-                } else {
-                    level = ((level * 2 + 1) * qscale) >> 1;
-                    level = (level - 1) | 1;
-                }
-            }
-
-            block[j] = level;
-            if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-                break;
-            UPDATE_CACHE(re, &s->gb);
-        }
-end:
-        LAST_SKIP_BITS(re, &s->gb, 2);
-        CLOSE_READER(re, &s->gb);
-    }
-    s->block_last_index[n] = i;
-    return 0;
-}
-
-
-static inline int mpeg2_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n)
-{
-    int level, i, j, run;
-    RLTable *rl = &ff_rl_mpeg1;
-    uint8_t * const scantable = s->intra_scantable.permutated;
-    const uint16_t *quant_matrix;
-    const int qscale = s->qscale;
-    int mismatch;
-
-    mismatch = 1;
-
-    {
-        OPEN_READER(re, &s->gb);
-        i = -1;
-        if (n < 4)
-            quant_matrix = s->inter_matrix;
-        else
-            quant_matrix = s->chroma_inter_matrix;
-
-        // special case for first coefficient, no need to add second VLC table
-        UPDATE_CACHE(re, &s->gb);
-        if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
-            level= (3 * qscale * quant_matrix[0]) >> 5;
-            if (GET_CACHE(re, &s->gb) & 0x40000000)
-                level = -level;
-            block[0]  = level;
-            mismatch ^= level;
-            i++;
-            SKIP_BITS(re, &s->gb, 2);
-            if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-                goto end;
-        }
-
-        /* now quantify & encode AC coefficients */
-        for (;;) {
-            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-            if (level != 0) {
-                i += run;
-                j = scantable[i];
-                level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
-                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-                SKIP_BITS(re, &s->gb, 1);
-            } else {
-                /* escape */
-                run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
-                UPDATE_CACHE(re, &s->gb);
-                level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
-
-                i += run;
-                j = scantable[i];
-                if (level < 0) {
-                    level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
-                    level = -level;
-                } else {
-                    level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
-                }
-            }
-            if (i > 63) {
-                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
-            }
-
-            mismatch ^= level;
-            block[j]  = level;
-            if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-                break;
-            UPDATE_CACHE(re, &s->gb);
-        }
-end:
-        LAST_SKIP_BITS(re, &s->gb, 2);
-        CLOSE_READER(re, &s->gb);
-    }
-    block[63] ^= (mismatch & 1);
-
-    s->block_last_index[n] = i;
-    return 0;
-}
-
-static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
-                                                    DCTELEM *block, int n)
-{
-    int level, i, j, run;
-    RLTable *rl = &ff_rl_mpeg1;
-    uint8_t * const scantable = s->intra_scantable.permutated;
-    const int qscale          = s->qscale;
-    OPEN_READER(re, &s->gb);
-    i = -1;
-
-    // special case for first coefficient, no need to add second VLC table
-    UPDATE_CACHE(re, &s->gb);
-    if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
-        level = (3 * qscale) >> 1;
-        if (GET_CACHE(re, &s->gb) & 0x40000000)
-            level = -level;
-        block[0] = level;
-        i++;
-        SKIP_BITS(re, &s->gb, 2);
-        if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-            goto end;
-    }
-
-    /* now quantify & encode AC coefficients */
-    for (;;) {
-        GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-        if (level != 0) {
-            i += run;
-            j  = scantable[i];
-            level = ((level * 2 + 1) * qscale) >> 1;
-            level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-            SKIP_BITS(re, &s->gb, 1);
-        } else {
-            /* escape */
-            run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
-            UPDATE_CACHE(re, &s->gb);
-            level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
-
-            i += run;
-            j  = scantable[i];
-            if (level < 0) {
-                level = ((-level * 2 + 1) * qscale) >> 1;
-                level = -level;
-            } else {
-                level = ((level * 2 + 1) * qscale) >> 1;
-            }
-        }
-
-        block[j] = level;
-        if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
-            break;
-        UPDATE_CACHE(re, &s->gb);
-    }
-end:
-    LAST_SKIP_BITS(re, &s->gb, 2);
-    CLOSE_READER(re, &s->gb);
-    s->block_last_index[n] = i;
-    return 0;
-}
-
-
-static inline int mpeg2_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n)
-{
-    int level, dc, diff, i, j, run;
-    int component;
-    RLTable *rl;
-    uint8_t * const scantable = s->intra_scantable.permutated;
-    const uint16_t *quant_matrix;
-    const int qscale = s->qscale;
-    int mismatch;
-
-    /* DC coefficient */
-    if (n < 4) {
-        quant_matrix = s->intra_matrix;
-        component = 0;
-    } else {
-        quant_matrix = s->chroma_intra_matrix;
-        component = (n & 1) + 1;
-    }
-    diff = decode_dc(&s->gb, component);
-    if (diff >= 0xffff)
-        return -1;
-    dc  = s->last_dc[component];
-    dc += diff;
-    s->last_dc[component] = dc;
-    block[0] = dc << (3 - s->intra_dc_precision);
-    av_dlog(s->avctx, "dc=%d\n", block[0]);
-    mismatch = block[0] ^ 1;
-    i = 0;
-    if (s->intra_vlc_format)
-        rl = &ff_rl_mpeg2;
-    else
-        rl = &ff_rl_mpeg1;
-
-    {
-        OPEN_READER(re, &s->gb);
-        /* now quantify & encode AC coefficients */
-        for (;;) {
-            UPDATE_CACHE(re, &s->gb);
-            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-            if (level == 127) {
-                break;
-            } else if (level != 0) {
-                i += run;
-                j  = scantable[i];
-                level = (level * qscale * quant_matrix[j]) >> 4;
-                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-                LAST_SKIP_BITS(re, &s->gb, 1);
-            } else {
-                /* escape */
-                run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
-                UPDATE_CACHE(re, &s->gb);
-                level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
-                i += run;
-                j  = scantable[i];
-                if (level < 0) {
-                    level = (-level * qscale * quant_matrix[j]) >> 4;
-                    level = -level;
-                } else {
-                    level = (level * qscale * quant_matrix[j]) >> 4;
-                }
-            }
-            if (i > 63) {
-                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
-            }
-
-            mismatch ^= level;
-            block[j]  = level;
-        }
-        CLOSE_READER(re, &s->gb);
-    }
-    block[63] ^= mismatch & 1;
-
-    s->block_last_index[n] = i;
-    return 0;
-}
-
-static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n)
-{
-    int level, dc, diff, j, run;
-    int component;
-    RLTable *rl;
-    uint8_t * scantable = s->intra_scantable.permutated;
-    const uint16_t *quant_matrix;
-    const int qscale = s->qscale;
-
-    /* DC coefficient */
-    if (n < 4) {
-        quant_matrix = s->intra_matrix;
-        component = 0;
-    } else {
-        quant_matrix = s->chroma_intra_matrix;
-        component = (n & 1) + 1;
-    }
-    diff = decode_dc(&s->gb, component);
-    if (diff >= 0xffff)
-        return -1;
-    dc = s->last_dc[component];
-    dc += diff;
-    s->last_dc[component] = dc;
-    block[0] = dc << (3 - s->intra_dc_precision);
-    if (s->intra_vlc_format)
-        rl = &ff_rl_mpeg2;
-    else
-        rl = &ff_rl_mpeg1;
-
-    {
-        OPEN_READER(re, &s->gb);
-        /* now quantify & encode AC coefficients */
-        for (;;) {
-            UPDATE_CACHE(re, &s->gb);
-            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
-
-            if (level == 127) {
-                break;
-            } else if (level != 0) {
-                scantable += run;
-                j = *scantable;
-                level = (level * qscale * quant_matrix[j]) >> 4;
-                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
-                LAST_SKIP_BITS(re, &s->gb, 1);
-            } else {
-                /* escape */
-                run = SHOW_UBITS(re, &s->gb, 6) + 1; LAST_SKIP_BITS(re, &s->gb, 6);
-                UPDATE_CACHE(re, &s->gb);
-                level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
-                scantable += run;
-                j = *scantable;
-                if (level < 0) {
-                    level = (-level * qscale * quant_matrix[j]) >> 4;
-                    level = -level;
-                } else {
-                    level = (level * qscale * quant_matrix[j]) >> 4;
-                }
-            }
-
-            block[j] = level;
-        }
-        CLOSE_READER(re, &s->gb);
-    }
-
-    s->block_last_index[n] = scantable - s->intra_scantable.permutated;
-    return 0;
-}
+static const uint8_t table_mb_ptype[7][2] = {
+    { 3, 5 }, // 0x01 MB_INTRA
+    { 1, 2 }, // 0x02 MB_PAT
+    { 1, 3 }, // 0x08 MB_FOR
+    { 1, 1 }, // 0x0A MB_FOR|MB_PAT
+    { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
+    { 1, 5 }, // 0x12 MB_QUANT|MB_PAT
+    { 2, 5 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
+};
 
-uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
+static const uint8_t table_mb_btype[11][2] = {
+    { 3, 5 }, // 0x01 MB_INTRA
+    { 2, 3 }, // 0x04 MB_BACK
+    { 3, 3 }, // 0x06 MB_BACK|MB_PAT
+    { 2, 4 }, // 0x08 MB_FOR
+    { 3, 4 }, // 0x0A MB_FOR|MB_PAT
+    { 2, 2 }, // 0x0C MB_FOR|MB_BACK
+    { 3, 2 }, // 0x0E MB_FOR|MB_BACK|MB_PAT
+    { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
+    { 2, 6 }, // 0x16 MB_QUANT|MB_BACK|MB_PAT
+    { 3, 6 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
+    { 2, 5 }, // 0x1E MB_QUANT|MB_FOR|MB_BACK|MB_PAT
+};
 
 #define INIT_2D_VLC_RL(rl, static_size)\
 {\
@@ -604,7 +78,7 @@ uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
     init_2d_vlc_rl(&rl);\
 }
 
-static void init_2d_vlc_rl(RLTable *rl)
+static av_cold void init_2d_vlc_rl(RLTable *rl)
 {
     int i;
 
@@ -637,7 +111,7 @@ static void init_2d_vlc_rl(RLTable *rl)
     }
 }
 
-void ff_mpeg12_common_init(MpegEncContext *s)
+av_cold void ff_mpeg12_common_init(MpegEncContext *s)
 {
 
     s->y_dc_scale_table =
@@ -657,13 +131,15 @@ void ff_mpeg1_clean_buffers(MpegEncContext *s)
 /******************************************/
 /* decoding */
 
+VLC ff_mv_vlc;
+
 VLC ff_dc_lum_vlc;
 VLC ff_dc_chroma_vlc;
 
-static VLC mbincr_vlc;
-static VLC mb_ptype_vlc;
-static VLC mb_btype_vlc;
-static VLC mb_pat_vlc;
+VLC ff_mbincr_vlc;
+VLC ff_mb_ptype_vlc;
+VLC ff_mb_btype_vlc;
+VLC ff_mb_pat_vlc;
 
 av_cold void ff_mpeg12_init_vlcs(void)
 {
@@ -678,20 +154,20 @@ av_cold void ff_mpeg12_init_vlcs(void)
         INIT_VLC_STATIC(&ff_dc_chroma_vlc,  DC_VLC_BITS, 12,
                         ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
                         ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
-        INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
+        INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
                         &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
                         &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
-        INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
+        INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
                         &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
                         &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
-        INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
+        INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
                         &ff_mpeg12_mbPatTable[0][1], 2, 1,
                         &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 
-        INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
+        INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
                         &table_mb_ptype[0][1], 2, 1,
                         &table_mb_ptype[0][0], 2, 1, 64);
-        INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
+        INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
                         &table_mb_btype[0][1], 2, 1,
                         &table_mb_btype[0][0], 2, 1, 64);
         ff_init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
@@ -702,1991 +178,67 @@ av_cold void ff_mpeg12_init_vlcs(void)
     }
 }
 
-static inline int get_dmv(MpegEncContext *s)
-{
-    if (get_bits1(&s->gb))
-        return 1 - (get_bits1(&s->gb) << 1);
-    else
-        return 0;
-}
-
-static inline int get_qscale(MpegEncContext *s)
-{
-    int qscale = get_bits(&s->gb, 5);
-    if (s->q_scale_type) {
-        return non_linear_qscale[qscale];
-    } else {
-        return qscale << 1;
-    }
-}
-
-static void exchange_uv(MpegEncContext *s)
-{
-    DCTELEM (*tmp)[64];
-
-    tmp           = s->pblocks[4];
-    s->pblocks[4] = s->pblocks[5];
-    s->pblocks[5] = tmp;
-}
-
-/* motion type (for MPEG-2) */
-#define MT_FIELD 1
-#define MT_FRAME 2
-#define MT_16X8  2
-#define MT_DMV   3
-
-static int mpeg_decode_mb(MpegEncContext *s, DCTELEM block[12][64])
+/**
+ * Find the end of the current frame in the bitstream.
+ * @return the position of the first byte of the next frame, or -1
+ */
+int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
 {
-    int i, j, k, cbp, val, mb_type, motion_type;
-    const int mb_block_count = 4 + (1 << s->chroma_format);
-
-    av_dlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
-
-    av_assert2(s->mb_skipped == 0);
-
-    if (s->mb_skip_run-- != 0) {
-        if (s->pict_type == AV_PICTURE_TYPE_P) {
-            s->mb_skipped = 1;
-            s->current_picture.f.mb_type[s->mb_x + s->mb_y * s->mb_stride] = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
-        } else {
-            int mb_type;
-
-            if (s->mb_x)
-                mb_type = s->current_picture.f.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
-            else
-                mb_type = s->current_picture.f.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1]; // FIXME not sure if this is allowed in MPEG at all
-            if (IS_INTRA(mb_type))
-                return -1;
-            s->current_picture.f.mb_type[s->mb_x + s->mb_y*s->mb_stride] =
-                mb_type | MB_TYPE_SKIP;
-//            av_assert2(s->current_picture.f.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1] & (MB_TYPE_16x16 | MB_TYPE_16x8));
-
-            if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
-                s->mb_skipped = 1;
-        }
+    int i;
+    uint32_t state = pc->state;
 
+    /* EOF considered as end of frame */
+    if (buf_size == 0)
         return 0;
-    }
-
-    switch (s->pict_type) {
-    default:
-    case AV_PICTURE_TYPE_I:
-        if (get_bits1(&s->gb) == 0) {
-            if (get_bits1(&s->gb) == 0) {
-                av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
-            }
-            mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
-        } else {
-            mb_type = MB_TYPE_INTRA;
-        }
-        break;
-    case AV_PICTURE_TYPE_P:
-        mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
-        if (mb_type < 0) {
-            av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
-            return -1;
-        }
-        mb_type = ptype2mb_type[mb_type];
-        break;
-    case AV_PICTURE_TYPE_B:
-        mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
-        if (mb_type < 0) {
-            av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
-            return -1;
-        }
-        mb_type = btype2mb_type[mb_type];
-        break;
-    }
-    av_dlog(s->avctx, "mb_type=%x\n", mb_type);
-//    motion_type = 0; /* avoid warning */
-    if (IS_INTRA(mb_type)) {
-        s->dsp.clear_blocks(s->block[0]);
-
-        if (!s->chroma_y_shift) {
-            s->dsp.clear_blocks(s->block[6]);
-        }
-
-        /* compute DCT type */
-        if (s->picture_structure == PICT_FRAME && // FIXME add an interlaced_dct coded var?
-            !s->frame_pred_frame_dct) {
-            s->interlaced_dct = get_bits1(&s->gb);
-        }
-
-        if (IS_QUANT(mb_type))
-            s->qscale = get_qscale(s);
-
-        if (s->concealment_motion_vectors) {
-            /* just parse them */
-            if (s->picture_structure != PICT_FRAME)
-                skip_bits1(&s->gb); /* field select */
-
-            s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
-                mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
-            s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
-                mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 
-            skip_bits1(&s->gb); /* marker */
-        } else
-            memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
-        s->mb_intra = 1;
-        // if 1, we memcpy blocks in xvmcvideo
-        if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1) {
-            ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
-            if (s->swap_uv) {
-                exchange_uv(s);
-            }
-        }
-
-        if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
-            if (s->flags2 & CODEC_FLAG2_FAST) {
-                for (i = 0; i < 6; i++) {
-                    mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
-                }
-            } else {
-                for (i = 0; i < mb_block_count; i++) {
-                    if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
-                        return -1;
-                }
-            }
-        } else {
-            for (i = 0; i < 6; i++) {
-                if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
-                    return -1;
-            }
-        }
-    } else {
-        if (mb_type & MB_TYPE_ZERO_MV) {
-            av_assert2(mb_type & MB_TYPE_CBP);
+/*
+ 0  frame start         -> 1/4
+ 1  first_SEQEXT        -> 0/2
+ 2  first field start   -> 3/0
+ 3  second_SEQEXT       -> 2/0
+ 4  searching end
+*/
 
-            s->mv_dir = MV_DIR_FORWARD;
-            if (s->picture_structure == PICT_FRAME) {
-                if (!s->frame_pred_frame_dct)
-                    s->interlaced_dct = get_bits1(&s->gb);
-                s->mv_type = MV_TYPE_16X16;
-            } else {
-                s->mv_type = MV_TYPE_FIELD;
-                mb_type |= MB_TYPE_INTERLACED;
-                s->field_select[0][0] = s->picture_structure - 1;
+    for (i = 0; i < buf_size; i++) {
+        av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
+        if (pc->frame_start_found & 1) {
+            if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
+                pc->frame_start_found--;
+            else if (state == EXT_START_CODE + 2) {
+                if ((buf[i] & 3) == 3)
+                    pc->frame_start_found = 0;
+                else
+                    pc->frame_start_found = (pc->frame_start_found + 1) & 3;
             }
-
-            if (IS_QUANT(mb_type))
-                s->qscale = get_qscale(s);
-
-            s->last_mv[0][0][0] = 0;
-            s->last_mv[0][0][1] = 0;
-            s->last_mv[0][1][0] = 0;
-            s->last_mv[0][1][1] = 0;
-            s->mv[0][0][0] = 0;
-            s->mv[0][0][1] = 0;
+            state++;
         } else {
-            av_assert2(mb_type & MB_TYPE_L0L1);
-            // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
-            /* get additional motion vector type */
-            if (s->frame_pred_frame_dct)
-                motion_type = MT_FRAME;
-            else {
-                motion_type = get_bits(&s->gb, 2);
-                if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
-                    s->interlaced_dct = get_bits1(&s->gb);
-            }
-
-            if (IS_QUANT(mb_type))
-                s->qscale = get_qscale(s);
-
-            /* motion vectors */
-            s->mv_dir = (mb_type >> 13) & 3;
-            av_dlog(s->avctx, "motion_type=%d\n", motion_type);
-            switch (motion_type) {
-            case MT_FRAME: /* or MT_16X8 */
-                if (s->picture_structure == PICT_FRAME) {
-                    mb_type |= MB_TYPE_16x16;
-                    s->mv_type = MV_TYPE_16X16;
-                    for (i = 0; i < 2; i++) {
-                        if (USES_LIST(mb_type, i)) {
-                            /* MT_FRAME */
-                            s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
-                                mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
-                            s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
-                                mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
-                            /* full_pel: only for MPEG-1 */
-                            if (s->full_pel[i]) {
-                                s->mv[i][0][0] <<= 1;
-                                s->mv[i][0][1] <<= 1;
-                            }
-                        }
-                    }
-                } else {
-                    mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
-                    s->mv_type = MV_TYPE_16X8;
-                    for (i = 0; i < 2; i++) {
-                        if (USES_LIST(mb_type, i)) {
-                            /* MT_16X8 */
-                            for (j = 0; j < 2; j++) {
-                                s->field_select[i][j] = get_bits1(&s->gb);
-                                for (k = 0; k < 2; k++) {
-                                    val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
-                                                             s->last_mv[i][j][k]);
-                                    s->last_mv[i][j][k] = val;
-                                    s->mv[i][j][k]      = val;
-                                }
-                            }
-                        }
-                    }
-                }
-                break;
-            case MT_FIELD:
-                s->mv_type = MV_TYPE_FIELD;
-                if (s->picture_structure == PICT_FRAME) {
-                    mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
-                    for (i = 0; i < 2; i++) {
-                        if (USES_LIST(mb_type, i)) {
-                            for (j = 0; j < 2; j++) {
-                                s->field_select[i][j] = get_bits1(&s->gb);
-                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
-                                                         s->last_mv[i][j][0]);
-                                s->last_mv[i][j][0] = val;
-                                s->mv[i][j][0]      = val;
-                                av_dlog(s->avctx, "fmx=%d\n", val);
-                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
-                                                         s->last_mv[i][j][1] >> 1);
-                                s->last_mv[i][j][1] = val << 1;
-                                s->mv[i][j][1]      = val;
-                                av_dlog(s->avctx, "fmy=%d\n", val);
-                            }
-                        }
-                    }
-                } else {
-                    av_assert0(!s->progressive_sequence);
-                    mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
-                    for (i = 0; i < 2; i++) {
-                        if (USES_LIST(mb_type, i)) {
-                            s->field_select[i][0] = get_bits1(&s->gb);
-                            for (k = 0; k < 2; k++) {
-                                val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
-                                                         s->last_mv[i][0][k]);
-                                s->last_mv[i][0][k] = val;
-                                s->last_mv[i][1][k] = val;
-                                s->mv[i][0][k]      = val;
-                            }
-                        }
-                    }
-                }
-                break;
-            case MT_DMV:
-                if(s->progressive_sequence){
-                    av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
-                    return -1;
-                }
-                s->mv_type = MV_TYPE_DMV;
-                for (i = 0; i < 2; i++) {
-                    if (USES_LIST(mb_type, i)) {
-                        int dmx, dmy, mx, my, m;
-                        const int my_shift = s->picture_structure == PICT_FRAME;
-
-                        mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
-                                                s->last_mv[i][0][0]);
-                        s->last_mv[i][0][0] = mx;
-                        s->last_mv[i][1][0] = mx;
-                        dmx = get_dmv(s);
-                        my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
-                                                 s->last_mv[i][0][1] >> my_shift);
-                        dmy = get_dmv(s);
-
-
-                        s->last_mv[i][0][1] = my << my_shift;
-                        s->last_mv[i][1][1] = my << my_shift;
-
-                        s->mv[i][0][0] = mx;
-                        s->mv[i][0][1] = my;
-                        s->mv[i][1][0] = mx; // not used
-                        s->mv[i][1][1] = my; // not used
-
-                        if (s->picture_structure == PICT_FRAME) {
-                            mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
-
-                            // m = 1 + 2 * s->top_field_first;
-                            m = s->top_field_first ? 1 : 3;
-
-                            /* top -> top pred */
-                            s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
-                            s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
-                            m = 4 - m;
-                            s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
-                            s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
-                        } else {
-                            mb_type |= MB_TYPE_16x16;
-
-                            s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
-                            s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
-                            if (s->picture_structure == PICT_TOP_FIELD)
-                                s->mv[i][2][1]--;
-                            else
-                                s->mv[i][2][1]++;
-                        }
-                    }
-                }
-                break;
-            default:
-                av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
-            }
-        }
-
-        s->mb_intra = 0;
-        if (HAS_CBP(mb_type)) {
-            s->dsp.clear_blocks(s->block[0]);
-
-            cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
-            if (mb_block_count > 6) {
-                 cbp <<= mb_block_count - 6;
-                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
-                 s->dsp.clear_blocks(s->block[6]);
+            i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
+            if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
+                i++;
+                pc->frame_start_found = 4;
             }
-            if (cbp <= 0) {
-                av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
-                return -1;
+            if (state == SEQ_END_CODE) {
+                pc->frame_start_found = 0;
+                pc->state=-1;
+                return i+1;
             }
-
-            //if 1, we memcpy blocks in xvmcvideo
-            if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1) {
-                ff_xvmc_pack_pblocks(s, cbp);
-                if (s->swap_uv) {
-                    exchange_uv(s);
+            if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
+                pc->frame_start_found = 0;
+            if (pc->frame_start_found  < 4 && state == EXT_START_CODE)
+                pc->frame_start_found++;
+            if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
+                if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
+                    pc->frame_start_found = 0;
+                    pc->state             = -1;
+                    return i - 3;
                 }
             }
-
-            if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
-                if (s->flags2 & CODEC_FLAG2_FAST) {
-                    for (i = 0; i < 6; i++) {
-                        if (cbp & 32) {
-                            mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
-                        } else {
-                            s->block_last_index[i] = -1;
-                        }
-                        cbp += cbp;
-                    }
-                } else {
-                    cbp <<= 12-mb_block_count;
-
-                    for (i = 0; i < mb_block_count; i++) {
-                        if (cbp & (1 << 11)) {
-                            if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
-                                return -1;
-                        } else {
-                            s->block_last_index[i] = -1;
-                        }
-                        cbp += cbp;
-                    }
-                }
-            } else {
-                if (s->flags2 & CODEC_FLAG2_FAST) {
-                    for (i = 0; i < 6; i++) {
-                        if (cbp & 32) {
-                            mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
-                        } else {
-                            s->block_last_index[i] = -1;
-                        }
-                        cbp += cbp;
-                    }
-                } else {
-                    for (i = 0; i < 6; i++) {
-                        if (cbp & 32) {
-                            if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
-                                return -1;
-                        } else {
-                            s->block_last_index[i] = -1;
-                        }
-                        cbp += cbp;
-                    }
-                }
+            if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
+                ff_fetch_timestamp(s, i - 3, 1);
             }
-        } else {
-            for (i = 0; i < 12; i++)
-                s->block_last_index[i] = -1;
         }
     }
-
-    s->current_picture.f.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
-
-    return 0;
+    pc->state = state;
+    return END_NOT_FOUND;
 }
 
-static av_cold int mpeg_decode_init(AVCodecContext *avctx)
-{
-    Mpeg1Context *s = avctx->priv_data;
-    MpegEncContext *s2 = &s->mpeg_enc_ctx;
-    int i;
-
-    /* we need some permutation to store matrices,
-     * until MPV_common_init() sets the real permutation. */
-    for (i = 0; i < 64; i++)
-       s2->dsp.idct_permutation[i]=i;
-
-    ff_MPV_decode_defaults(s2);
-
-    s->mpeg_enc_ctx.avctx  = avctx;
-    s->mpeg_enc_ctx.flags  = avctx->flags;
-    s->mpeg_enc_ctx.flags2 = avctx->flags2;
-    ff_mpeg12_common_init(&s->mpeg_enc_ctx);
-    ff_mpeg12_init_vlcs();
-
-    s->mpeg_enc_ctx_allocated      = 0;
-    s->mpeg_enc_ctx.picture_number = 0;
-    s->repeat_field                = 0;
-    s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
-    avctx->color_range = AVCOL_RANGE_MPEG;
-    if (avctx->codec->id == CODEC_ID_MPEG1VIDEO)
-        avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
-    else
-        avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
-    return 0;
-}
-
-static int mpeg_decode_update_thread_context(AVCodecContext *avctx, const AVCodecContext *avctx_from)
-{
-    Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
-    MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
-    int err;
-
-    if (avctx == avctx_from || !ctx_from->mpeg_enc_ctx_allocated || !s1->context_initialized)
-        return 0;
-
-    err = ff_mpeg_update_thread_context(avctx, avctx_from);
-    if (err) return err;
-
-    if (!ctx->mpeg_enc_ctx_allocated)
-        memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
-
-    if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
-        s->picture_number++;
-
-    return 0;
-}
-
-static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
-                                 const uint8_t *new_perm)
-{
-    uint16_t temp_matrix[64];
-    int i;
-
-    memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
-
-    for (i = 0; i < 64; i++) {
-        matrix[new_perm[i]] = temp_matrix[old_perm[i]];
-    }
-}
-
-static const enum PixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
-#if CONFIG_MPEG_XVMC_DECODER
-    PIX_FMT_XVMC_MPEG2_IDCT,
-    PIX_FMT_XVMC_MPEG2_MC,
-#endif
-#if CONFIG_MPEG1_VDPAU_HWACCEL
-    PIX_FMT_VDPAU_MPEG1,
-#endif
-    PIX_FMT_YUV420P,
-    PIX_FMT_NONE
-};
-
-static const enum PixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
-#if CONFIG_MPEG_XVMC_DECODER
-    PIX_FMT_XVMC_MPEG2_IDCT,
-    PIX_FMT_XVMC_MPEG2_MC,
-#endif
-#if CONFIG_MPEG2_VDPAU_HWACCEL
-    PIX_FMT_VDPAU_MPEG2,
-#endif
-#if CONFIG_MPEG2_DXVA2_HWACCEL
-    PIX_FMT_DXVA2_VLD,
-#endif
-#if CONFIG_MPEG2_VAAPI_HWACCEL
-    PIX_FMT_VAAPI_VLD,
-#endif
-    PIX_FMT_YUV420P,
-    PIX_FMT_NONE
-};
-
-static inline int uses_vdpau(AVCodecContext *avctx) {
-    return avctx->pix_fmt == PIX_FMT_VDPAU_MPEG1 || avctx->pix_fmt == PIX_FMT_VDPAU_MPEG2;
-}
-
-static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
-{
-    Mpeg1Context *s1 = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-
-    if(s->chroma_format < 2) {
-        enum PixelFormat res;
-        res = avctx->get_format(avctx,
-                                avctx->codec_id == CODEC_ID_MPEG1VIDEO ?
-                                mpeg1_hwaccel_pixfmt_list_420 :
-                                mpeg2_hwaccel_pixfmt_list_420);
-        if (res != PIX_FMT_XVMC_MPEG2_IDCT && res != PIX_FMT_XVMC_MPEG2_MC) {
-            avctx->xvmc_acceleration = 0;
-        } else if (!avctx->xvmc_acceleration) {
-            avctx->xvmc_acceleration = 2;
-        }
-        return res;
-    } else if(s->chroma_format == 2)
-        return PIX_FMT_YUV422P;
-    else
-        return PIX_FMT_YUV444P;
-}
-
-/* Call this function when we know all parameters.
- * It may be called in different places for MPEG-1 and MPEG-2. */
-static int mpeg_decode_postinit(AVCodecContext *avctx)
-{
-    Mpeg1Context *s1 = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    uint8_t old_permutation[64];
-
-    if ((s1->mpeg_enc_ctx_allocated == 0) ||
-        avctx->coded_width  != s->width   ||
-        avctx->coded_height != s->height  ||
-        s1->save_width           != s->width                ||
-        s1->save_height          != s->height               ||
-        s1->save_aspect_info     != s->aspect_ratio_info    ||
-        s1->save_progressive_seq != s->progressive_sequence ||
-        0)
-    {
-
-        if (s1->mpeg_enc_ctx_allocated) {
-            ParseContext pc = s->parse_context;
-            s->parse_context.buffer = 0;
-            ff_MPV_common_end(s);
-            s->parse_context = pc;
-        }
-
-        if ((s->width == 0) || (s->height == 0))
-            return -2;
-
-        avcodec_set_dimensions(avctx, s->width, s->height);
-        avctx->bit_rate          = s->bit_rate;
-        s1->save_aspect_info     = s->aspect_ratio_info;
-        s1->save_width           = s->width;
-        s1->save_height          = s->height;
-        s1->save_progressive_seq = s->progressive_sequence;
-
-        /* low_delay may be forced, in this case we will have B-frames
-         * that behave like P-frames. */
-        avctx->has_b_frames = !s->low_delay;
-
-        if (avctx->codec_id == CODEC_ID_MPEG1VIDEO) {
-            //MPEG-1 fps
-            avctx->time_base.den = avpriv_frame_rate_tab[s->frame_rate_index].num;
-            avctx->time_base.num = avpriv_frame_rate_tab[s->frame_rate_index].den;
-            //MPEG-1 aspect
-            avctx->sample_aspect_ratio = av_d2q(1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
-            avctx->ticks_per_frame=1;
-        } else {//MPEG-2
-        //MPEG-2 fps
-            av_reduce(&s->avctx->time_base.den,
-                      &s->avctx->time_base.num,
-                      avpriv_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
-                      avpriv_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
-                      1 << 30);
-            avctx->ticks_per_frame = 2;
-            //MPEG-2 aspect
-            if (s->aspect_ratio_info > 1) {
-                AVRational dar =
-                    av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
-                                      (AVRational) {s1->pan_scan.width, s1->pan_scan.height}),
-                             (AVRational) {s->width, s->height});
-
-                // we ignore the spec here and guess a bit as reality does not match the spec, see for example
-                // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
-                // issue1613, 621, 562
-                if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
-                   (av_cmp_q(dar, (AVRational) {4, 3}) && av_cmp_q(dar, (AVRational) {16, 9}))) {
-                    s->avctx->sample_aspect_ratio =
-                        av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
-                                 (AVRational) {s->width, s->height});
-                } else {
-                    s->avctx->sample_aspect_ratio =
-                        av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
-                                 (AVRational) {s1->pan_scan.width, s1->pan_scan.height});
-//issue1613 4/3 16/9 -> 16/9
-//res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
-//widescreen-issue562.mpg 4/3 16/9 -> 16/9
-//                    s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
-//av_log(NULL, AV_LOG_ERROR, "A %d/%d\n", ff_mpeg2_aspect[s->aspect_ratio_info].num, ff_mpeg2_aspect[s->aspect_ratio_info].den);
-//av_log(NULL, AV_LOG_ERROR, "B %d/%d\n", s->avctx->sample_aspect_ratio.num, s->avctx->sample_aspect_ratio.den);
-                }
-            } else {
-                s->avctx->sample_aspect_ratio =
-                    ff_mpeg2_aspect[s->aspect_ratio_info];
-            }
-        } // MPEG-2
-
-        avctx->pix_fmt = mpeg_get_pixelformat(avctx);
-        avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
-        // until then pix_fmt may be changed right after codec init
-        if (avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
-            avctx->hwaccel )
-            if (avctx->idct_algo == FF_IDCT_AUTO)
-                avctx->idct_algo = FF_IDCT_SIMPLE;
-
-        /* Quantization matrices may need reordering
-         * if DCT permutation is changed. */
-        memcpy(old_permutation, s->dsp.idct_permutation, 64 * sizeof(uint8_t));
-
-        if (ff_MPV_common_init(s) < 0)
-            return -2;
-
-        quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->dsp.idct_permutation);
-        quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->dsp.idct_permutation);
-        quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->dsp.idct_permutation);
-        quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->dsp.idct_permutation);
-
-        s1->mpeg_enc_ctx_allocated = 1;
-    }
-    return 0;
-}
-
-static int mpeg1_decode_picture(AVCodecContext *avctx,
-                                const uint8_t *buf, int buf_size)
-{
-    Mpeg1Context *s1 = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    int ref, f_code, vbv_delay;
-
-    init_get_bits(&s->gb, buf, buf_size*8);
-
-    ref = get_bits(&s->gb, 10); /* temporal ref */
-    s->pict_type = get_bits(&s->gb, 3);
-    if (s->pict_type == 0 || s->pict_type > 3)
-        return -1;
-
-    vbv_delay = get_bits(&s->gb, 16);
-    if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type == AV_PICTURE_TYPE_B) {
-        s->full_pel[0] = get_bits1(&s->gb);
-        f_code = get_bits(&s->gb, 3);
-        if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
-            return -1;
-        f_code += !f_code;
-        s->mpeg_f_code[0][0] = f_code;
-        s->mpeg_f_code[0][1] = f_code;
-    }
-    if (s->pict_type == AV_PICTURE_TYPE_B) {
-        s->full_pel[1] = get_bits1(&s->gb);
-        f_code = get_bits(&s->gb, 3);
-        if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
-            return -1;
-        f_code += !f_code;
-        s->mpeg_f_code[1][0] = f_code;
-        s->mpeg_f_code[1][1] = f_code;
-    }
-    s->current_picture.f.pict_type = s->pict_type;
-    s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
-
-    if (avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
-
-    s->y_dc_scale = 8;
-    s->c_dc_scale = 8;
-    return 0;
-}
-
-static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
-{
-    MpegEncContext *s= &s1->mpeg_enc_ctx;
-    int horiz_size_ext, vert_size_ext;
-    int bit_rate_ext;
-
-    skip_bits(&s->gb, 1); /* profile and level esc*/
-    s->avctx->profile       = get_bits(&s->gb, 3);
-    s->avctx->level         = get_bits(&s->gb, 4);
-    s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
-    s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
-    horiz_size_ext          = get_bits(&s->gb, 2);
-    vert_size_ext           = get_bits(&s->gb, 2);
-    s->width  |= (horiz_size_ext << 12);
-    s->height |= (vert_size_ext  << 12);
-    bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
-    s->bit_rate += (bit_rate_ext << 18) * 400;
-    skip_bits1(&s->gb); /* marker */
-    s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
-
-    s->low_delay = get_bits1(&s->gb);
-    if (s->flags & CODEC_FLAG_LOW_DELAY)
-        s->low_delay = 1;
-
-    s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
-    s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
-
-    av_dlog(s->avctx, "sequence extension\n");
-    s->codec_id      = s->avctx->codec_id = CODEC_ID_MPEG2VIDEO;
-
-    if (s->avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
-               s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
-
-}
-
-static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
-{
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    int color_description, w, h;
-
-    skip_bits(&s->gb, 3); /* video format */
-    color_description = get_bits1(&s->gb);
-    if (color_description) {
-        s->avctx->color_primaries = get_bits(&s->gb, 8);
-        s->avctx->color_trc       = get_bits(&s->gb, 8);
-        s->avctx->colorspace      = get_bits(&s->gb, 8);
-    }
-    w = get_bits(&s->gb, 14);
-    skip_bits(&s->gb, 1); //marker
-    h = get_bits(&s->gb, 14);
-    // remaining 3 bits are zero padding
-
-    s1->pan_scan.width  = 16 * w;
-    s1->pan_scan.height = 16 * h;
-
-    if (s->avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
-}
-
-static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
-{
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    int i, nofco;
-
-    nofco = 1;
-    if (s->progressive_sequence) {
-        if (s->repeat_first_field) {
-            nofco++;
-            if (s->top_field_first)
-                nofco++;
-        }
-    } else {
-        if (s->picture_structure == PICT_FRAME) {
-            nofco++;
-            if (s->repeat_first_field)
-                nofco++;
-        }
-    }
-    for (i = 0; i < nofco; i++) {
-        s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
-        skip_bits(&s->gb, 1); // marker
-        s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
-        skip_bits(&s->gb, 1); // marker
-    }
-
-    if (s->avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
-               s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
-               s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
-               s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
-}
-
-static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra)
-{
-    int i;
-
-    for (i = 0; i < 64; i++) {
-        int j = s->dsp.idct_permutation[ff_zigzag_direct[i]];
-        int v = get_bits(&s->gb, 8);
-        if (v == 0) {
-            av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
-            return -1;
-        }
-        if (intra && i == 0 && v != 8) {
-            av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
-            v = 8; // needed by pink.mpg / issue1046
-        }
-        matrix0[j] = v;
-        if (matrix1)
-            matrix1[j] = v;
-    }
-    return 0;
-}
-
-static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
-{
-    av_dlog(s->avctx, "matrix extension\n");
-
-    if (get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
-    if (get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
-    if (get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
-    if (get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
-}
-
-static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
-{
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-
-    s->full_pel[0] = s->full_pel[1] = 0;
-    s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
-    s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
-    s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
-    s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
-    if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
-        av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
-        if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
-            if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
-                s->pict_type = AV_PICTURE_TYPE_I;
-            else
-                s->pict_type = AV_PICTURE_TYPE_P;
-        } else
-            s->pict_type = AV_PICTURE_TYPE_B;
-        s->current_picture.f.pict_type = s->pict_type;
-        s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
-    }
-    s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
-    s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
-    s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
-    s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
-
-    s->intra_dc_precision         = get_bits(&s->gb, 2);
-    s->picture_structure          = get_bits(&s->gb, 2);
-    s->top_field_first            = get_bits1(&s->gb);
-    s->frame_pred_frame_dct       = get_bits1(&s->gb);
-    s->concealment_motion_vectors = get_bits1(&s->gb);
-    s->q_scale_type               = get_bits1(&s->gb);
-    s->intra_vlc_format           = get_bits1(&s->gb);
-    s->alternate_scan             = get_bits1(&s->gb);
-    s->repeat_first_field         = get_bits1(&s->gb);
-    s->chroma_420_type            = get_bits1(&s->gb);
-    s->progressive_frame          = get_bits1(&s->gb);
-
-    if (s->progressive_sequence && !s->progressive_frame) {
-        s->progressive_frame = 1;
-        av_log(s->avctx, AV_LOG_ERROR, "interlaced frame in progressive sequence, ignoring\n");
-    }
-
-    if (s->picture_structure == 0 || (s->progressive_frame && s->picture_structure != PICT_FRAME)) {
-        av_log(s->avctx, AV_LOG_ERROR, "picture_structure %d invalid, ignoring\n", s->picture_structure);
-        s->picture_structure = PICT_FRAME;
-    }
-
-    if (s->progressive_sequence && !s->frame_pred_frame_dct) {
-        av_log(s->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
-    }
-
-    if (s->picture_structure == PICT_FRAME) {
-        s->first_field = 0;
-        s->v_edge_pos  = 16 * s->mb_height;
-    } else {
-        s->first_field ^= 1;
-        s->v_edge_pos   = 8 * s->mb_height;
-        memset(s->mbskip_table, 0, s->mb_stride * s->mb_height);
-    }
-
-    if (s->alternate_scan) {
-        ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
-        ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
-    } else {
-        ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
-        ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
-    }
-
-    /* composite display not parsed */
-    av_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
-    av_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
-    av_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
-    av_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
-    av_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
-    av_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
-    av_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
-    av_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
-    av_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
-}
-
-static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
-{
-    AVCodecContext *avctx = s->avctx;
-    Mpeg1Context *s1 = (Mpeg1Context*)s;
-
-    /* start frame decoding */
-    if (s->first_field || s->picture_structure == PICT_FRAME) {
-        if (ff_MPV_frame_start(s, avctx) < 0)
-            return -1;
-
-        ff_er_frame_start(s);
-
-        /* first check if we must repeat the frame */
-        s->current_picture_ptr->f.repeat_pict = 0;
-        if (s->repeat_first_field) {
-            if (s->progressive_sequence) {
-                if (s->top_field_first)
-                    s->current_picture_ptr->f.repeat_pict = 4;
-                else
-                    s->current_picture_ptr->f.repeat_pict = 2;
-            } else if (s->progressive_frame) {
-                s->current_picture_ptr->f.repeat_pict = 1;
-            }
-        }
-
-        *s->current_picture_ptr->f.pan_scan = s1->pan_scan;
-
-        if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
-            ff_thread_finish_setup(avctx);
-    } else { // second field
-        int i;
-
-        if (!s->current_picture_ptr) {
-            av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
-            return -1;
-        }
-
-        if (s->avctx->hwaccel &&
-            (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
-            if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
-                av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode first field\n");
-        }
-
-        for (i = 0; i < 4; i++) {
-            s->current_picture.f.data[i] = s->current_picture_ptr->f.data[i];
-            if (s->picture_structure == PICT_BOTTOM_FIELD) {
-                s->current_picture.f.data[i] += s->current_picture_ptr->f.linesize[i];
-            }
-        }
-    }
-
-    if (avctx->hwaccel) {
-        if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
-            return -1;
-    }
-
-// MPV_frame_start will call this function too,
-// but we need to call it on every field
-    if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
-        if (ff_xvmc_field_start(s, avctx) < 0)
-            return -1;
-
-    return 0;
-}
-
-#define DECODE_SLICE_ERROR -1
-#define DECODE_SLICE_OK     0
-
-/**
- * Decode a slice.
- * MpegEncContext.mb_y must be set to the MB row from the startcode.
- * @return DECODE_SLICE_ERROR if the slice is damaged,
- *         DECODE_SLICE_OK if this slice is OK
- */
-static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
-                             const uint8_t **buf, int buf_size)
-{
-    AVCodecContext *avctx = s->avctx;
-    const int lowres      = s->avctx->lowres;
-    const int field_pic   = s->picture_structure != PICT_FRAME;
-
-    s->resync_mb_x =
-    s->resync_mb_y = -1;
-
-    av_assert0(mb_y < s->mb_height);
-
-    init_get_bits(&s->gb, *buf, buf_size * 8);
-    if(s->codec_id != CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
-        skip_bits(&s->gb, 3);
-
-    ff_mpeg1_clean_buffers(s);
-    s->interlaced_dct = 0;
-
-    s->qscale = get_qscale(s);
-
-    if (s->qscale == 0) {
-        av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
-        return -1;
-    }
-
-    /* extra slice info */
-    while (get_bits1(&s->gb) != 0) {
-        skip_bits(&s->gb, 8);
-    }
-
-    s->mb_x = 0;
-
-    if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
-        skip_bits1(&s->gb);
-    } else {
-        while (get_bits_left(&s->gb) > 0) {
-            int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
-            if (code < 0) {
-                av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
-                return -1;
-            }
-            if (code >= 33) {
-                if (code == 33) {
-                    s->mb_x += 33;
-                }
-                /* otherwise, stuffing, nothing to do */
-            } else {
-                s->mb_x += code;
-                break;
-            }
-        }
-    }
-
-    if (s->mb_x >= (unsigned)s->mb_width) {
-        av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
-        return -1;
-    }
-
-    if (avctx->hwaccel) {
-        const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
-        int start_code = -1;
-        buf_end = avpriv_mpv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
-        if (buf_end < *buf + buf_size)
-            buf_end -= 4;
-        s->mb_y = mb_y;
-        if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
-            return DECODE_SLICE_ERROR;
-        *buf = buf_end;
-        return DECODE_SLICE_OK;
-    }
-
-    s->resync_mb_x = s->mb_x;
-    s->resync_mb_y = s->mb_y = mb_y;
-    s->mb_skip_run = 0;
-    ff_init_block_index(s);
-
-    if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
-        if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
-             av_log(s->avctx, AV_LOG_DEBUG, "qp:%d fc:%2d%2d%2d%2d %s %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",
-                    s->qscale, s->mpeg_f_code[0][0], s->mpeg_f_code[0][1], s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
-                    s->pict_type == AV_PICTURE_TYPE_I ? "I" : (s->pict_type == AV_PICTURE_TYPE_P ? "P" : (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
-                    s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
-                    s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
-                    s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
-        }
-    }
-
-    for (;;) {
-        // If 1, we memcpy blocks in xvmcvideo.
-        if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
-            ff_xvmc_init_block(s); // set s->block
-
-        if (mpeg_decode_mb(s, s->block) < 0)
-            return -1;
-
-        if (s->current_picture.f.motion_val[0] && !s->encoding) { // note motion_val is normally NULL unless we want to extract the MVs
-            const int wrap = s->b8_stride;
-            int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
-            int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
-            int motion_x, motion_y, dir, i;
-
-            for (i = 0; i < 2; i++) {
-                for (dir = 0; dir < 2; dir++) {
-                    if (s->mb_intra || (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
-                        motion_x = motion_y = 0;
-                    } else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)) {
-                        motion_x = s->mv[dir][0][0];
-                        motion_y = s->mv[dir][0][1];
-                    } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
-                        motion_x = s->mv[dir][i][0];
-                        motion_y = s->mv[dir][i][1];
-                    }
-
-                    s->current_picture.f.motion_val[dir][xy    ][0] = motion_x;
-                    s->current_picture.f.motion_val[dir][xy    ][1] = motion_y;
-                    s->current_picture.f.motion_val[dir][xy + 1][0] = motion_x;
-                    s->current_picture.f.motion_val[dir][xy + 1][1] = motion_y;
-                    s->current_picture.f.ref_index [dir][b8_xy    ] =
-                    s->current_picture.f.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
-                    av_assert2(s->field_select[dir][i] == 0 || s->field_select[dir][i] == 1);
-                }
-                xy += wrap;
-                b8_xy +=2;
-            }
-        }
-
-        s->dest[0] += 16 >> lowres;
-        s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
-        s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
-
-        ff_MPV_decode_mb(s, s->block);
-
-        if (++s->mb_x >= s->mb_width) {
-            const int mb_size = 16 >> s->avctx->lowres;
-
-            ff_draw_horiz_band(s, mb_size*(s->mb_y >> field_pic), mb_size);
-            ff_MPV_report_decode_progress(s);
-
-            s->mb_x = 0;
-            s->mb_y += 1 << field_pic;
-
-            if (s->mb_y >= s->mb_height) {
-                int left   = get_bits_left(&s->gb);
-                int is_d10 = s->chroma_format == 2 && s->pict_type == AV_PICTURE_TYPE_I && avctx->profile == 0 && avctx->level == 5
-                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
-                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
-
-                if (left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
-                    || ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
-                    av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
-                    return -1;
-                } else
-                    goto eos;
-            }
-
-            ff_init_block_index(s);
-        }
-
-        /* skip mb handling */
-        if (s->mb_skip_run == -1) {
-            /* read increment again */
-            s->mb_skip_run = 0;
-            for (;;) {
-                int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
-                if (code < 0) {
-                    av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
-                    return -1;
-                }
-                if (code >= 33) {
-                    if (code == 33) {
-                        s->mb_skip_run += 33;
-                    } else if (code == 35) {
-                        if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
-                            av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
-                            return -1;
-                        }
-                        goto eos; /* end of slice */
-                    }
-                    /* otherwise, stuffing, nothing to do */
-                } else {
-                    s->mb_skip_run += code;
-                    break;
-                }
-            }
-            if (s->mb_skip_run) {
-                int i;
-                if (s->pict_type == AV_PICTURE_TYPE_I) {
-                    av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
-                    return -1;
-                }
-
-                /* skip mb */
-                s->mb_intra = 0;
-                for (i = 0; i < 12; i++)
-                    s->block_last_index[i] = -1;
-                if (s->picture_structure == PICT_FRAME)
-                    s->mv_type = MV_TYPE_16X16;
-                else
-                    s->mv_type = MV_TYPE_FIELD;
-                if (s->pict_type == AV_PICTURE_TYPE_P) {
-                    /* if P type, zero motion vector is implied */
-                    s->mv_dir             = MV_DIR_FORWARD;
-                    s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
-                    s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
-                    s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
-                    s->field_select[0][0] = (s->picture_structure - 1) & 1;
-                } else {
-                    /* if B type, reuse previous vectors and directions */
-                    s->mv[0][0][0] = s->last_mv[0][0][0];
-                    s->mv[0][0][1] = s->last_mv[0][0][1];
-                    s->mv[1][0][0] = s->last_mv[1][0][0];
-                    s->mv[1][0][1] = s->last_mv[1][0][1];
-                }
-            }
-        }
-    }
-eos: // end of slice
-    *buf += (get_bits_count(&s->gb)-1)/8;
-//printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
-    return 0;
-}
-
-static int slice_decode_thread(AVCodecContext *c, void *arg)
-{
-    MpegEncContext *s   = *(void**)arg;
-    const uint8_t *buf  = s->gb.buffer;
-    int mb_y            = s->start_mb_y;
-    const int field_pic = s->picture_structure != PICT_FRAME;
-
-    s->error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
-
-    for (;;) {
-        uint32_t start_code;
-        int ret;
-
-        ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
-        emms_c();
-//av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
-//ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, s->start_mb_y, s->end_mb_y, s->error_count);
-        if (ret < 0) {
-            if (c->err_recognition & AV_EF_EXPLODE)
-                return ret;
-            if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
-                ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
-        } else {
-            ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_AC_END | ER_DC_END | ER_MV_END);
-        }
-
-        if (s->mb_y == s->end_mb_y)
-            return 0;
-
-        start_code = -1;
-        buf = avpriv_mpv_find_start_code(buf, s->gb.buffer_end, &start_code);
-        mb_y= start_code - SLICE_MIN_START_CODE;
-        if(s->codec_id != CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
-            mb_y += (*buf&0xE0)<<2;
-        mb_y <<= field_pic;
-        if (s->picture_structure == PICT_BOTTOM_FIELD)
-            mb_y++;
-        if (mb_y < 0 || mb_y >= s->end_mb_y)
-            return -1;
-    }
-}
-
-/**
- * Handle slice ends.
- * @return 1 if it seems to be the last slice
- */
-static int slice_end(AVCodecContext *avctx, AVFrame *pict)
-{
-    Mpeg1Context *s1 = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-
-    if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
-        return 0;
-
-    if (s->avctx->hwaccel) {
-        if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
-            av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
-    }
-
-    if (CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
-        ff_xvmc_field_end(s);
-
-    /* end of slice reached */
-    if (/*s->mb_y << field_pic == s->mb_height &&*/ !s->first_field && !s->first_slice) {
-        /* end of image */
-
-        s->current_picture_ptr->f.qscale_type = FF_QSCALE_TYPE_MPEG2;
-
-        ff_er_frame_end(s);
-
-        ff_MPV_frame_end(s);
-
-        if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
-            *pict = s->current_picture_ptr->f;
-            ff_print_debug_info(s, pict);
-        } else {
-            if (avctx->active_thread_type & FF_THREAD_FRAME)
-                s->picture_number++;
-            /* latency of 1 frame for I- and P-frames */
-            /* XXX: use another variable than picture_number */
-            if (s->last_picture_ptr != NULL) {
-                *pict = s->last_picture_ptr->f;
-                 ff_print_debug_info(s, pict);
-            }
-        }
-
-        return 1;
-    } else {
-        return 0;
-    }
-}
-
-static int mpeg1_decode_sequence(AVCodecContext *avctx,
-                                 const uint8_t *buf, int buf_size)
-{
-    Mpeg1Context *s1 = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    int width, height;
-    int i, v, j;
-
-    init_get_bits(&s->gb, buf, buf_size*8);
-
-    width  = get_bits(&s->gb, 12);
-    height = get_bits(&s->gb, 12);
-    if (width <= 0 || height <= 0)
-        return -1;
-    s->aspect_ratio_info = get_bits(&s->gb, 4);
-    if (s->aspect_ratio_info == 0) {
-        av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
-        if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
-            return -1;
-    }
-    s->frame_rate_index = get_bits(&s->gb, 4);
-    if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
-        return -1;
-    s->bit_rate = get_bits(&s->gb, 18) * 400;
-    if (get_bits1(&s->gb) == 0) /* marker */
-        return -1;
-    s->width  = width;
-    s->height = height;
-
-    s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
-    skip_bits(&s->gb, 1);
-
-    /* get matrix */
-    if (get_bits1(&s->gb)) {
-        load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
-    } else {
-        for (i = 0; i < 64; i++) {
-            j = s->dsp.idct_permutation[i];
-            v = ff_mpeg1_default_intra_matrix[i];
-            s->intra_matrix[j]        = v;
-            s->chroma_intra_matrix[j] = v;
-        }
-    }
-    if (get_bits1(&s->gb)) {
-        load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
-    } else {
-        for (i = 0; i < 64; i++) {
-            int j = s->dsp.idct_permutation[i];
-            v = ff_mpeg1_default_non_intra_matrix[i];
-            s->inter_matrix[j]        = v;
-            s->chroma_inter_matrix[j] = v;
-        }
-    }
-
-    if (show_bits(&s->gb, 23) != 0) {
-        av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
-        return -1;
-    }
-
-    /* we set MPEG-2 parameters so that it emulates MPEG-1 */
-    s->progressive_sequence = 1;
-    s->progressive_frame    = 1;
-    s->picture_structure    = PICT_FRAME;
-    s->first_field          = 0;
-    s->frame_pred_frame_dct = 1;
-    s->chroma_format        = 1;
-    s->codec_id             = s->avctx->codec_id = CODEC_ID_MPEG1VIDEO;
-    s->out_format           = FMT_MPEG1;
-    s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
-    if (s->flags & CODEC_FLAG_LOW_DELAY)
-        s->low_delay = 1;
-
-    if (s->avctx->debug & FF_DEBUG_PICT_INFO)
-        av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
-               s->avctx->rc_buffer_size, s->bit_rate);
-
-    return 0;
-}
-
-static int vcr2_init_sequence(AVCodecContext *avctx)
-{
-    Mpeg1Context *s1 = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    int i, v;
-
-    /* start new MPEG-1 context decoding */
-    s->out_format = FMT_MPEG1;
-    if (s1->mpeg_enc_ctx_allocated) {
-        ff_MPV_common_end(s);
-    }
-    s->width  = avctx->coded_width;
-    s->height = avctx->coded_height;
-    avctx->has_b_frames = 0; // true?
-    s->low_delay = 1;
-
-    avctx->pix_fmt = mpeg_get_pixelformat(avctx);
-    avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
-
-    if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel )
-        if (avctx->idct_algo == FF_IDCT_AUTO)
-            avctx->idct_algo = FF_IDCT_SIMPLE;
-
-    if (ff_MPV_common_init(s) < 0)
-        return -1;
-    s1->mpeg_enc_ctx_allocated = 1;
-
-    for (i = 0; i < 64; i++) {
-        int j = s->dsp.idct_permutation[i];
-        v = ff_mpeg1_default_intra_matrix[i];
-        s->intra_matrix[j]        = v;
-        s->chroma_intra_matrix[j] = v;
-
-        v = ff_mpeg1_default_non_intra_matrix[i];
-        s->inter_matrix[j]        = v;
-        s->chroma_inter_matrix[j] = v;
-    }
-
-    s->progressive_sequence  = 1;
-    s->progressive_frame     = 1;
-    s->picture_structure     = PICT_FRAME;
-    s->first_field           = 0;
-    s->frame_pred_frame_dct  = 1;
-    s->chroma_format         = 1;
-    if (s->codec_tag == AV_RL32("BW10")) {
-        s->codec_id              = s->avctx->codec_id = CODEC_ID_MPEG1VIDEO;
-    } else {
-        exchange_uv(s); // common init reset pblocks, so we swap them here
-        s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
-        s->codec_id              = s->avctx->codec_id = CODEC_ID_MPEG2VIDEO;
-    }
-    s1->save_width           = s->width;
-    s1->save_height          = s->height;
-    s1->save_progressive_seq = s->progressive_sequence;
-    return 0;
-}
-
-
-static void mpeg_decode_user_data(AVCodecContext *avctx,
-                                  const uint8_t *p, int buf_size)
-{
-    Mpeg1Context *s = avctx->priv_data;
-    const uint8_t *buf_end = p + buf_size;
-
-    if(buf_size > 29){
-        int i;
-        for(i=0; i<20; i++)
-            if(!memcmp(p+i, "\0TMPGEXS\0", 9)){
-                s->tmpgexs= 1;
-            }
-
-/*        for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
-            av_log(0,0, "%c", p[i]);
-        }
-            av_log(0,0, "\n");*/
-    }
-
-    /* we parse the DTG active format information */
-    if (buf_end - p >= 5 &&
-        p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
-        int flags = p[4];
-        p += 5;
-        if (flags & 0x80) {
-            /* skip event id */
-            p += 2;
-        }
-        if (flags & 0x40) {
-            if (buf_end - p < 1)
-                return;
-            avctx->dtg_active_format = p[0] & 0x0f;
-        }
-    }
-}
-
-static void mpeg_decode_gop(AVCodecContext *avctx,
-                            const uint8_t *buf, int buf_size)
-{
-    Mpeg1Context *s1  = avctx->priv_data;
-    MpegEncContext *s = &s1->mpeg_enc_ctx;
-    int broken_link;
-    int64_t tc;
-
-    init_get_bits(&s->gb, buf, buf_size*8);
-
-    tc = avctx->timecode_frame_start = get_bits(&s->gb, 25);
-
-    s->closed_gop = get_bits1(&s->gb);
-    /*broken_link indicate that after editing the
-      reference frames of the first B-Frames after GOP I-Frame
-      are missing (open gop)*/
-    broken_link = get_bits1(&s->gb);
-
-    if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
-        char tcbuf[AV_TIMECODE_STR_SIZE];
-        av_timecode_make_mpeg_tc_string(tcbuf, tc);
-        av_log(s->avctx, AV_LOG_DEBUG,
-               "GOP (%s) closed_gop=%d broken_link=%d\n",
-               tcbuf, s->closed_gop, broken_link);
-    }
-}
-/**
- * Find the end of the current frame in the bitstream.
- * @return the position of the first byte of the next frame, or -1
- */
-int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
-{
-    int i;
-    uint32_t state = pc->state;
-
-    /* EOF considered as end of frame */
-    if (buf_size == 0)
-        return 0;
-
-/*
- 0  frame start         -> 1/4
- 1  first_SEQEXT        -> 0/2
- 2  first field start   -> 3/0
- 3  second_SEQEXT       -> 2/0
- 4  searching end
-*/
-
-    for (i = 0; i < buf_size; i++) {
-        av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
-        if (pc->frame_start_found & 1) {
-            if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
-                pc->frame_start_found--;
-            else if (state == EXT_START_CODE + 2) {
-                if ((buf[i] & 3) == 3)
-                    pc->frame_start_found = 0;
-                else
-                    pc->frame_start_found = (pc->frame_start_found + 1) & 3;
-            }
-            state++;
-        } else {
-            i = avpriv_mpv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
-            if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
-                i++;
-                pc->frame_start_found = 4;
-            }
-            if (state == SEQ_END_CODE) {
-                pc->frame_start_found = 0;
-                pc->state=-1;
-                return i+1;
-            }
-            if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
-                pc->frame_start_found = 0;
-            if (pc->frame_start_found  < 4 && state == EXT_START_CODE)
-                pc->frame_start_found++;
-            if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
-                if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
-                    pc->frame_start_found = 0;
-                    pc->state             = -1;
-                    return i - 3;
-                }
-            }
-            if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
-                ff_fetch_timestamp(s, i - 3, 1);
-            }
-        }
-    }
-    pc->state = state;
-    return END_NOT_FOUND;
-}
-
-static int decode_chunks(AVCodecContext *avctx,
-                         AVFrame *picture, int *data_size,
-                         const uint8_t *buf, int buf_size);
-
-/* handle buffering and image synchronisation */
-static int mpeg_decode_frame(AVCodecContext *avctx,
-                             void *data, int *data_size,
-                             AVPacket *avpkt)
-{
-    const uint8_t *buf = avpkt->data;
-    int buf_size = avpkt->size;
-    Mpeg1Context *s = avctx->priv_data;
-    AVFrame *picture = data;
-    MpegEncContext *s2 = &s->mpeg_enc_ctx;
-    av_dlog(avctx, "fill_buffer\n");
-
-    if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
-        /* special case for last picture */
-        if (s2->low_delay == 0 && s2->next_picture_ptr) {
-            *picture = s2->next_picture_ptr->f;
-            s2->next_picture_ptr = NULL;
-
-            *data_size = sizeof(AVFrame);
-        }
-        return buf_size;
-    }
-
-    if (s2->flags & CODEC_FLAG_TRUNCATED) {
-        int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
-
-        if (ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0)
-            return buf_size;
-    }
-
-    s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
-    if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
-                                           || s2->codec_tag == AV_RL32("BW10")
-                                          ))
-        vcr2_init_sequence(avctx);
-
-    s->slice_count = 0;
-
-    if (avctx->extradata && !s->parsed_extra) {
-        int ret = decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
-        if(*data_size) {
-            av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
-            *data_size = 0;
-        }
-        s->parsed_extra = 1;
-        if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
-            return ret;
-    }
-
-    return decode_chunks(avctx, picture, data_size, buf, buf_size);
-}
-
-static int decode_chunks(AVCodecContext *avctx,
-                         AVFrame *picture, int *data_size,
-                         const uint8_t *buf, int buf_size)
-{
-    Mpeg1Context *s = avctx->priv_data;
-    MpegEncContext *s2 = &s->mpeg_enc_ctx;
-    const uint8_t *buf_ptr = buf;
-    const uint8_t *buf_end = buf + buf_size;
-    int ret, input_size;
-    int last_code = 0;
-
-    for (;;) {
-        /* find next start code */
-        uint32_t start_code = -1;
-        buf_ptr = avpriv_mpv_find_start_code(buf_ptr, buf_end, &start_code);
-        if (start_code > 0x1ff) {
-            if (s2->pict_type != AV_PICTURE_TYPE_B || avctx->skip_frame <= AVDISCARD_DEFAULT) {
-                if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE)) {
-                    int i;
-                    av_assert0(avctx->thread_count > 1);
-
-                    avctx->execute(avctx, slice_decode_thread,  &s2->thread_context[0], NULL, s->slice_count, sizeof(void*));
-                    for (i = 0; i < s->slice_count; i++)
-                        s2->error_count += s2->thread_context[i]->error_count;
-                }
-
-                if (CONFIG_VDPAU && uses_vdpau(avctx))
-                    ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
-
-
-                if (slice_end(avctx, picture)) {
-                    if (s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
-                        *data_size = sizeof(AVPicture);
-                }
-            }
-            s2->pict_type = 0;
-            return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
-        }
-
-        input_size = buf_end - buf_ptr;
-
-        if (avctx->debug & FF_DEBUG_STARTCODE) {
-            av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
-        }
-
-        /* prepare data for next start code */
-        switch (start_code) {
-        case SEQ_START_CODE:
-            if (last_code == 0) {
-                mpeg1_decode_sequence(avctx, buf_ptr, input_size);
-                if(buf != avctx->extradata)
-                    s->sync=1;
-            } else {
-                av_log(avctx, AV_LOG_ERROR, "ignoring SEQ_START_CODE after %X\n", last_code);
-                if (avctx->err_recognition & AV_EF_EXPLODE)
-                    return AVERROR_INVALIDDATA;
-            }
-            break;
-
-        case PICTURE_START_CODE:
-            if(s->tmpgexs){
-                s2->intra_dc_precision= 3;
-                s2->intra_matrix[0]= 1;
-            }
-            if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) && s->slice_count) {
-                int i;
-
-                avctx->execute(avctx, slice_decode_thread,
-                               s2->thread_context, NULL,
-                               s->slice_count, sizeof(void*));
-                for (i = 0; i < s->slice_count; i++)
-                    s2->error_count += s2->thread_context[i]->error_count;
-                s->slice_count = 0;
-            }
-            if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
-                ret = mpeg_decode_postinit(avctx);
-                if (ret < 0) {
-                    av_log(avctx, AV_LOG_ERROR, "mpeg_decode_postinit() failure\n");
-                    return ret;
-                }
-
-                /* we have a complete image: we try to decompress it */
-                if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
-                    s2->pict_type = 0;
-                s2->first_slice = 1;
-                last_code = PICTURE_START_CODE;
-            } else {
-                av_log(avctx, AV_LOG_ERROR, "ignoring pic after %X\n", last_code);
-                if (avctx->err_recognition & AV_EF_EXPLODE)
-                    return AVERROR_INVALIDDATA;
-            }
-            break;
-        case EXT_START_CODE:
-            init_get_bits(&s2->gb, buf_ptr, input_size*8);
-
-            switch (get_bits(&s2->gb, 4)) {
-            case 0x1:
-                if (last_code == 0) {
-                mpeg_decode_sequence_extension(s);
-                } else {
-                    av_log(avctx, AV_LOG_ERROR, "ignoring seq ext after %X\n", last_code);
-                    if (avctx->err_recognition & AV_EF_EXPLODE)
-                        return AVERROR_INVALIDDATA;
-                }
-                break;
-            case 0x2:
-                mpeg_decode_sequence_display_extension(s);
-                break;
-            case 0x3:
-                mpeg_decode_quant_matrix_extension(s2);
-                break;
-            case 0x7:
-                mpeg_decode_picture_display_extension(s);
-                break;
-            case 0x8:
-                if (last_code == PICTURE_START_CODE) {
-                    mpeg_decode_picture_coding_extension(s);
-                } else {
-                    av_log(avctx, AV_LOG_ERROR, "ignoring pic cod ext after %X\n", last_code);
-                    if (avctx->err_recognition & AV_EF_EXPLODE)
-                        return AVERROR_INVALIDDATA;
-                }
-                break;
-            }
-            break;
-        case USER_START_CODE:
-            mpeg_decode_user_data(avctx, buf_ptr, input_size);
-            break;
-        case GOP_START_CODE:
-            if (last_code == 0) {
-                s2->first_field=0;
-                mpeg_decode_gop(avctx, buf_ptr, input_size);
-                s->sync=1;
-            } else {
-                av_log(avctx, AV_LOG_ERROR, "ignoring GOP_START_CODE after %X\n", last_code);
-                if (avctx->err_recognition & AV_EF_EXPLODE)
-                    return AVERROR_INVALIDDATA;
-            }
-            break;
-        default:
-            if (start_code >= SLICE_MIN_START_CODE &&
-                start_code <= SLICE_MAX_START_CODE && last_code != 0) {
-                const int field_pic = s2->picture_structure != PICT_FRAME;
-                int mb_y = start_code - SLICE_MIN_START_CODE;
-                last_code = SLICE_MIN_START_CODE;
-                if(s2->codec_id != CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
-                    mb_y += (*buf_ptr&0xE0)<<2;
-
-                mb_y <<= field_pic;
-                if (s2->picture_structure == PICT_BOTTOM_FIELD)
-                    mb_y++;
-
-                if (mb_y >= s2->mb_height) {
-                    av_log(s2->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
-                    return -1;
-                }
-
-                if (s2->last_picture_ptr == NULL) {
-                /* Skip B-frames if we do not have reference frames and gop is not closed */
-                    if (s2->pict_type == AV_PICTURE_TYPE_B) {
-                        if (!s2->closed_gop)
-                            break;
-                    }
-                }
-                if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->flags2 & CODEC_FLAG2_SHOW_ALL))
-                    s->sync=1;
-                if (s2->next_picture_ptr == NULL) {
-                /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
-                    if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) break;
-                }
-                if ((avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type == AV_PICTURE_TYPE_B) ||
-                    (avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type != AV_PICTURE_TYPE_I) ||
-                     avctx->skip_frame >= AVDISCARD_ALL)
-                    break;
-
-                if (!s->mpeg_enc_ctx_allocated)
-                    break;
-
-                if (s2->codec_id == CODEC_ID_MPEG2VIDEO) {
-                    if (mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
-                        break;
-                }
-
-                if (!s2->pict_type) {
-                    av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
-                    if (avctx->err_recognition & AV_EF_EXPLODE)
-                        return AVERROR_INVALIDDATA;
-                    break;
-                }
-
-                if (s2->first_slice) {
-                    s2->first_slice = 0;
-                    if (mpeg_field_start(s2, buf, buf_size) < 0)
-                        return -1;
-                }
-                if (!s2->current_picture_ptr) {
-                    av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
-                    return AVERROR_INVALIDDATA;
-                }
-
-                if (uses_vdpau(avctx)) {
-                    s->slice_count++;
-                    break;
-                }
-
-                if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE)) {
-                    int threshold = (s2->mb_height * s->slice_count +
-                                     s2->slice_context_count / 2) /
-                                    s2->slice_context_count;
-                    av_assert0(avctx->thread_count > 1);
-                    if (threshold <= mb_y) {
-                        MpegEncContext *thread_context = s2->thread_context[s->slice_count];
-
-                        thread_context->start_mb_y = mb_y;
-                        thread_context->end_mb_y   = s2->mb_height;
-                        if (s->slice_count) {
-                            s2->thread_context[s->slice_count-1]->end_mb_y = mb_y;
-                            ff_update_duplicate_context(thread_context, s2);
-                        }
-                        init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
-                        s->slice_count++;
-                    }
-                    buf_ptr += 2; // FIXME add minimum number of bytes per slice
-                } else {
-                    ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
-                    emms_c();
-
-                    if (ret < 0) {
-                        if (avctx->err_recognition & AV_EF_EXPLODE)
-                            return ret;
-                        if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
-                            ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
-                    } else {
-                        ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x-1, s2->mb_y, ER_AC_END | ER_DC_END | ER_MV_END);
-                    }
-                }
-            }
-            break;
-        }
-    }
-}
-
-static void flush(AVCodecContext *avctx)
-{
-    Mpeg1Context *s = avctx->priv_data;
-
-    s->sync=0;
-
-    ff_mpeg_flush(avctx);
-}
-
-static int mpeg_decode_end(AVCodecContext *avctx)
-{
-    Mpeg1Context *s = avctx->priv_data;
-
-    if (s->mpeg_enc_ctx_allocated)
-        ff_MPV_common_end(&s->mpeg_enc_ctx);
-    return 0;
-}
-
-static const AVProfile mpeg2_video_profiles[] = {
-    { FF_PROFILE_MPEG2_422,          "4:2:2"              },
-    { FF_PROFILE_MPEG2_HIGH,         "High"               },
-    { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
-    { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
-    { FF_PROFILE_MPEG2_MAIN,         "Main"               },
-    { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
-    { FF_PROFILE_RESERVED,           "Reserved"           },
-    { FF_PROFILE_RESERVED,           "Reserved"           },
-    { FF_PROFILE_UNKNOWN },
-};
-
-
-AVCodec ff_mpeg1video_decoder = {
-    .name                  = "mpeg1video",
-    .type                  = AVMEDIA_TYPE_VIDEO,
-    .id                    = CODEC_ID_MPEG1VIDEO,
-    .priv_data_size        = sizeof(Mpeg1Context),
-    .init                  = mpeg_decode_init,
-    .close                 = mpeg_decode_end,
-    .decode                = mpeg_decode_frame,
-    .capabilities          = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
-                             CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
-                             CODEC_CAP_SLICE_THREADS,
-    .flush                 = flush,
-    .max_lowres            = 3,
-    .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
-    .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
-};
-
-AVCodec ff_mpeg2video_decoder = {
-    .name           = "mpeg2video",
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = CODEC_ID_MPEG2VIDEO,
-    .priv_data_size = sizeof(Mpeg1Context),
-    .init           = mpeg_decode_init,
-    .close          = mpeg_decode_end,
-    .decode         = mpeg_decode_frame,
-    .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
-                      CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
-                      CODEC_CAP_SLICE_THREADS,
-    .flush          = flush,
-    .max_lowres     = 3,
-    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
-    .profiles       = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
-};
-
-//legacy decoder
-AVCodec ff_mpegvideo_decoder = {
-    .name           = "mpegvideo",
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = CODEC_ID_MPEG2VIDEO,
-    .priv_data_size = sizeof(Mpeg1Context),
-    .init           = mpeg_decode_init,
-    .close          = mpeg_decode_end,
-    .decode         = mpeg_decode_frame,
-    .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_SLICE_THREADS,
-    .flush          = flush,
-    .max_lowres     = 3,
-    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
-};
-
-#if CONFIG_MPEG_XVMC_DECODER
-static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
-{
-    if (avctx->active_thread_type & FF_THREAD_SLICE)
-        return -1;
-    if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
-        return -1;
-    if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
-        av_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
-    }
-    mpeg_decode_init(avctx);
-
-    avctx->pix_fmt           = PIX_FMT_XVMC_MPEG2_IDCT;
-    avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
-
-    return 0;
-}
-
-AVCodec ff_mpeg_xvmc_decoder = {
-    .name           = "mpegvideo_xvmc",
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = CODEC_ID_MPEG2VIDEO_XVMC,
-    .priv_data_size = sizeof(Mpeg1Context),
-    .init           = mpeg_mc_decode_init,
-    .close          = mpeg_decode_end,
-    .decode         = mpeg_decode_frame,
-    .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
-                      CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
-    .flush          = flush,
-    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
-};
-
-#endif
-
-#if CONFIG_MPEG_VDPAU_DECODER
-AVCodec ff_mpeg_vdpau_decoder = {
-    .name           = "mpegvideo_vdpau",
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = CODEC_ID_MPEG2VIDEO,
-    .priv_data_size = sizeof(Mpeg1Context),
-    .init           = mpeg_decode_init,
-    .close          = mpeg_decode_end,
-    .decode         = mpeg_decode_frame,
-    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED |
-                      CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
-    .flush          = flush,
-    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
-};
-#endif
-
-#if CONFIG_MPEG1_VDPAU_DECODER
-AVCodec ff_mpeg1_vdpau_decoder = {
-    .name           = "mpeg1video_vdpau",
-    .type           = AVMEDIA_TYPE_VIDEO,
-    .id             = CODEC_ID_MPEG1VIDEO,
-    .priv_data_size = sizeof(Mpeg1Context),
-    .init           = mpeg_decode_init,
-    .close          = mpeg_decode_end,
-    .decode         = mpeg_decode_frame,
-    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED |
-                      CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
-    .flush          = flush,
-    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
-};
-#endif