VP8: idct_mb optimizations
[ffmpeg.git] / libavcodec / parser.c
index 7b01da4..d877f5d 100644 (file)
@@ -1,27 +1,33 @@
 /*
  * Audio and Video frame extraction
- * Copyright (c) 2003 Fabrice Bellard.
- * Copyright (c) 2003 Michael Niedermayer.
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2003 Michael Niedermayer
  *
- * This library is free software; you can redistribute it and/or
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
-#include "avcodec.h"
-#include "mpegvideo.h"
-#include "mpegaudio.h"
 
-AVCodecParser *av_first_parser = NULL;
+#include "parser.h"
+
+static AVCodecParser *av_first_parser = NULL;
+
+AVCodecParser* av_parser_next(AVCodecParser *p){
+    if(p) return p->next;
+    else  return av_first_parser;
+}
 
 void av_register_codec_parser(AVCodecParser *parser)
 {
@@ -35,10 +41,15 @@ AVCodecParserContext *av_parser_init(int codec_id)
     AVCodecParser *parser;
     int ret;
 
+    if(codec_id == CODEC_ID_NONE)
+        return NULL;
+
     for(parser = av_first_parser; parser != NULL; parser = parser->next) {
         if (parser->codec_ids[0] == codec_id ||
             parser->codec_ids[1] == codec_id ||
-            parser->codec_ids[2] == codec_id)
+            parser->codec_ids[2] == codec_id ||
+            parser->codec_ids[3] == codec_id ||
+            parser->codec_ids[4] == codec_id)
             goto found;
     }
     return NULL;
@@ -61,75 +72,125 @@ AVCodecParserContext *av_parser_init(int codec_id)
         }
     }
     s->fetch_timestamp=1;
+    s->pict_type = FF_I_TYPE;
+    s->key_frame = -1;
+    s->convergence_duration = 0;
+    s->dts_sync_point       = INT_MIN;
+    s->dts_ref_dts_delta    = INT_MIN;
+    s->pts_dts_delta        = INT_MIN;
     return s;
 }
 
-/* NOTE: buf_size == 0 is used to signal EOF so that the last frame
-   can be returned if necessary */
-int av_parser_parse(AVCodecParserContext *s, 
+void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
+    int i;
+
+    s->dts= s->pts= AV_NOPTS_VALUE;
+    s->pos= -1;
+    s->offset= 0;
+    for(i = 0; i < AV_PARSER_PTS_NB; i++) {
+        if (   s->cur_offset + off >= s->cur_frame_offset[i]
+            && (s->frame_offset < s->cur_frame_offset[i] ||
+              (!s->frame_offset && !s->next_frame_offset)) // first field/frame
+            //check is disabled  because mpeg-ts doesnt send complete PES packets
+            && /*s->next_frame_offset + off <*/  s->cur_frame_end[i]){
+            s->dts= s->cur_frame_dts[i];
+            s->pts= s->cur_frame_pts[i];
+            s->pos= s->cur_frame_pos[i];
+            s->offset = s->next_frame_offset - s->cur_frame_offset[i];
+            if(remove)
+                s->cur_frame_offset[i]= INT64_MAX;
+            if(s->cur_offset + off < s->cur_frame_end[i])
+                break;
+        }
+    }
+}
+
+/**
+ *
+ * @param buf           input
+ * @param buf_size      input length, to signal EOF, this should be 0 (so that the last frame can be output)
+ * @param pts           input presentation timestamp
+ * @param dts           input decoding timestamp
+ * @param poutbuf       will contain a pointer to the first byte of the output frame
+ * @param poutbuf_size  will contain the length of the output frame
+ * @return the number of bytes of the input bitstream used
+ *
+ * Example:
+ * @code
+ *   while(in_len){
+ *       len = av_parser_parse(myparser, AVCodecContext, &data, &size,
+ *                                       in_data, in_len,
+ *                                       pts, dts);
+ *       in_data += len;
+ *       in_len  -= len;
+ *
+ *       if(size)
+ *          decode_frame(data, size);
+ *   }
+ * @endcode
+ *
+ * @deprecated Use av_parser_parse2() instead.
+ */
+int av_parser_parse(AVCodecParserContext *s,
                     AVCodecContext *avctx,
-                    uint8_t **poutbuf, int *poutbuf_size, 
+                    uint8_t **poutbuf, int *poutbuf_size,
                     const uint8_t *buf, int buf_size,
                     int64_t pts, int64_t dts)
 {
-    int index, i, k;
+    return av_parser_parse2(s, avctx, poutbuf, poutbuf_size, buf, buf_size, pts, dts, AV_NOPTS_VALUE);
+}
+
+int av_parser_parse2(AVCodecParserContext *s,
+                     AVCodecContext *avctx,
+                     uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size,
+                     int64_t pts, int64_t dts,
+                     int64_t pos)
+{
+    int index, i;
     uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
-    
+
+    if(!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
+        s->next_frame_offset =
+        s->cur_offset        = pos;
+        s->flags |= PARSER_FLAG_FETCHED_OFFSET;
+    }
+
     if (buf_size == 0) {
         /* padding is always necessary even if EOF, so we add it here */
         memset(dummy_buf, 0, sizeof(dummy_buf));
         buf = dummy_buf;
-    } else {
+    } else if (s->cur_offset + buf_size !=
+               s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
         /* add a new packet descriptor */
-        k = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
-        s->cur_frame_start_index = k;
-        s->cur_frame_offset[k] = s->cur_offset;
-        s->cur_frame_pts[k] = pts;
-        s->cur_frame_dts[k] = dts;
-
-        /* fill first PTS/DTS */
-        if (s->fetch_timestamp){
-            s->fetch_timestamp=0;
-            s->last_pts = pts;
-            s->last_dts = dts;
-            s->cur_frame_pts[k] =
-            s->cur_frame_dts[k] = AV_NOPTS_VALUE;
-        }
+            i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
+            s->cur_frame_start_index = i;
+            s->cur_frame_offset[i] = s->cur_offset;
+            s->cur_frame_end[i] = s->cur_offset + buf_size;
+            s->cur_frame_pts[i] = pts;
+            s->cur_frame_dts[i] = dts;
+            s->cur_frame_pos[i] = pos;
+    }
+
+    if (s->fetch_timestamp){
+        s->fetch_timestamp=0;
+        s->last_pts = s->pts;
+        s->last_dts = s->dts;
+        s->last_pos = s->pos;
+        ff_fetch_timestamp(s, 0, 0);
     }
 
     /* WARNING: the returned index can be negative */
-    index = s->parser->parser_parse(s, avctx, poutbuf, poutbuf_size, buf, buf_size);
-//av_log(NULL, AV_LOG_DEBUG, "parser: in:%lld, %lld, out:%lld, %lld, in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id);
+    index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
+//av_log(NULL, AV_LOG_DEBUG, "parser: in:%"PRId64", %"PRId64", out:%"PRId64", %"PRId64", in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id);
     /* update the file pointer */
     if (*poutbuf_size) {
         /* fill the data for the current frame */
-        s->frame_offset = s->last_frame_offset;
-        s->pts = s->last_pts;
-        s->dts = s->last_dts;
-        
-        /* offset of the next frame */
-        s->last_frame_offset = s->cur_offset + index;
-        /* find the packet in which the new frame starts. It
-           is tricky because of MPEG video start codes
-           which can begin in one packet and finish in
-           another packet. In the worst case, an MPEG
-           video start code could be in 4 different
-           packets. */
-        k = s->cur_frame_start_index;
-        for(i = 0; i < AV_PARSER_PTS_NB; i++) {
-            if (s->last_frame_offset >= s->cur_frame_offset[k])
-                break;
-            k = (k - 1) & (AV_PARSER_PTS_NB - 1);
-        }
+        s->frame_offset = s->next_frame_offset;
 
-        s->last_pts = s->cur_frame_pts[k];
-        s->last_dts = s->cur_frame_dts[k];
-        
-        /* some parsers tell us the packet size even before seeing the first byte of the next packet,
-           so the next pts/dts is in the next chunk */
-        if(index == buf_size){
-            s->fetch_timestamp=1;
-        }
+        /* offset of the next frame */
+        s->next_frame_offset = s->cur_offset + index;
+        s->fetch_timestamp=1;
     }
     if (index < 0)
         index = 0;
@@ -137,42 +198,61 @@ int av_parser_parse(AVCodecParserContext *s,
     return index;
 }
 
+/**
+ *
+ * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
+ * @deprecated use AVBitstreamFilter
+ */
+int av_parser_change(AVCodecParserContext *s,
+                     AVCodecContext *avctx,
+                     uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size, int keyframe){
+
+    if(s && s->parser->split){
+        if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
+            int i= s->parser->split(avctx, buf, buf_size);
+            buf += i;
+            buf_size -= i;
+        }
+    }
+
+    /* cast to avoid warning about discarding qualifiers */
+    *poutbuf= (uint8_t *) buf;
+    *poutbuf_size= buf_size;
+    if(avctx->extradata){
+        if(  (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
+            /*||(s->pict_type != FF_I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
+            /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
+            int size= buf_size + avctx->extradata_size;
+            *poutbuf_size= size;
+            *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
+
+            memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
+            memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
 void av_parser_close(AVCodecParserContext *s)
 {
-    if (s->parser->parser_close)
-        s->parser->parser_close(s);
-    av_free(s->priv_data);
-    av_free(s);
+    if(s){
+        if (s->parser->parser_close)
+            s->parser->parser_close(s);
+        av_free(s->priv_data);
+        av_free(s);
+    }
 }
 
 /*****************************************************/
 
-//#define END_NOT_FOUND (-100)
-
-#define PICTURE_START_CODE     0x00000100
-#define SEQ_START_CODE         0x000001b3
-#define EXT_START_CODE         0x000001b5
-#define SLICE_MIN_START_CODE   0x00000101
-#define SLICE_MAX_START_CODE   0x000001af
-
-typedef struct ParseContext1{
-    ParseContext pc;
-/* XXX/FIXME PC1 vs. PC */
-    /* MPEG2 specific */
-    int frame_rate;
-    int progressive_sequence;
-    int width, height;
-
-    /* XXX: suppress that, needed by MPEG4 */
-    MpegEncContext *enc;
-    int first_picture;
-} ParseContext1;
-
 /**
  * combines the (truncated) bitstream to a complete frame
- * @returns -1 if no complete frame could be created
+ * @return -1 if no complete frame could be created, AVERROR(ENOMEM) if there was a memory allocation error
  */
-int ff_combine_frame(ParseContext *pc, int next, uint8_t **buf, int *buf_size)
+int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
 {
 #if 0
     if(pc->overread){
@@ -181,17 +261,25 @@ int ff_combine_frame(ParseContext *pc, int next, uint8_t **buf, int *buf_size)
     }
 #endif
 
-    /* copy overreaded bytes from last frame into buffer */
+    /* Copy overread bytes from last frame into buffer. */
     for(; pc->overread>0; pc->overread--){
         pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
     }
-    
+
+    /* flush remaining if EOF */
+    if(!*buf_size && next == END_NOT_FOUND){
+        next= 0;
+    }
+
     pc->last_index= pc->index;
 
     /* copy into buffer end return */
     if(next == END_NOT_FOUND){
-        pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
+        void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
 
+        if(!new_buffer)
+            return AVERROR(ENOMEM);
+        pc->buffer = new_buffer;
         memcpy(&pc->buffer[pc->index], *buf, *buf_size);
         pc->index += *buf_size;
         return -1;
@@ -199,11 +287,14 @@ int ff_combine_frame(ParseContext *pc, int next, uint8_t **buf, int *buf_size)
 
     *buf_size=
     pc->overread_index= pc->index + next;
-    
+
     /* append to buffer */
     if(pc->index){
-        pc->buffer= av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
+        void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
 
+        if(!new_buffer)
+            return AVERROR(ENOMEM);
+        pc->buffer = new_buffer;
         memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
         pc->index = 0;
         *buf= pc->buffer;
@@ -212,6 +303,7 @@ int ff_combine_frame(ParseContext *pc, int next, uint8_t **buf, int *buf_size)
     /* store overread bytes */
     for(;next < 0; next++){
         pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
+        pc->state64 = (pc->state64<<8) | pc->buffer[pc->last_index + next];
         pc->overread++;
     }
 
@@ -225,181 +317,14 @@ int ff_combine_frame(ParseContext *pc, int next, uint8_t **buf, int *buf_size)
     return 0;
 }
 
-static int find_start_code(const uint8_t **pbuf_ptr, const uint8_t *buf_end)
-{
-    const uint8_t *buf_ptr;
-    unsigned int state=0xFFFFFFFF, v;
-    int val;
-
-    buf_ptr = *pbuf_ptr;
-    while (buf_ptr < buf_end) {
-        v = *buf_ptr++;
-        if (state == 0x000001) {
-            state = ((state << 8) | v) & 0xffffff;
-            val = state;
-            goto found;
-        }
-        state = ((state << 8) | v) & 0xffffff;
-    }
-    val = -1;
- found:
-    *pbuf_ptr = buf_ptr;
-    return val;
-}
-
-/* XXX: merge with libavcodec ? */
-#define MPEG1_FRAME_RATE_BASE 1001
-
-static const int frame_rate_tab[16] = {
-        0,        
-    24000,
-    24024,
-    25025,
-    30000,
-    30030,
-    50050,
-    60000,
-    60060,
-  // Xing's 15fps: (9)
-    15015,
-  // libmpeg3's "Unofficial economy rates": (10-13)
-     5005,
-    10010,
-    12012,
-    15015,
-  // random, just to avoid segfault !never encode these
-    25025,
-    25025,
-};
-
-static void mpegvideo_extract_headers(AVCodecParserContext *s, 
-                                      AVCodecContext *avctx,
-                                      const uint8_t *buf, int buf_size)
-{
-    ParseContext1 *pc = s->priv_data;
-    const uint8_t *buf_end;
-    int32_t start_code;
-    int frame_rate_index, ext_type, bytes_left;
-    int frame_rate_ext_n, frame_rate_ext_d;
-    int top_field_first, repeat_first_field, progressive_frame;
-    int horiz_size_ext, vert_size_ext;
-
-    s->repeat_pict = 0;
-    buf_end = buf + buf_size;
-    while (buf < buf_end) {
-        start_code = find_start_code(&buf, buf_end);
-        bytes_left = buf_end - buf;
-        switch(start_code) {
-        case PICTURE_START_CODE:
-            if (bytes_left >= 2) {
-                s->pict_type = (buf[1] >> 3) & 7;
-            }
-            break;
-        case SEQ_START_CODE:
-            if (bytes_left >= 4) {
-                pc->width = avctx->width = (buf[0] << 4) | (buf[1] >> 4);
-                pc->height = avctx->height = ((buf[1] & 0x0f) << 8) | buf[2];
-                frame_rate_index = buf[3] & 0xf;
-                pc->frame_rate = avctx->frame_rate = frame_rate_tab[frame_rate_index];
-                avctx->frame_rate_base = MPEG1_FRAME_RATE_BASE;
-                avctx->codec_id = CODEC_ID_MPEG1VIDEO;
-                avctx->sub_id = 1;
-            }
-            break;
-        case EXT_START_CODE:
-            if (bytes_left >= 1) {
-                ext_type = (buf[0] >> 4);
-                switch(ext_type) {
-                case 0x1: /* sequence extension */
-                    if (bytes_left >= 6) {
-                        horiz_size_ext = ((buf[1] & 1) << 1) | (buf[2] >> 7);
-                        vert_size_ext = (buf[2] >> 5) & 3;
-                        frame_rate_ext_n = (buf[5] >> 5) & 3;
-                        frame_rate_ext_d = (buf[5] & 0x1f);
-                        pc->progressive_sequence = buf[1] & (1 << 3);
-
-                        avctx->width = pc->width | (horiz_size_ext << 12);
-                        avctx->height = pc->height | (vert_size_ext << 12);
-                        avctx->frame_rate = pc->frame_rate * (frame_rate_ext_n + 1);
-                        avctx->frame_rate_base = MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d + 1);
-                        avctx->codec_id = CODEC_ID_MPEG2VIDEO;
-                        avctx->sub_id = 2; /* forces MPEG2 */
-                    }
-                    break;
-                case 0x8: /* picture coding extension */
-                    if (bytes_left >= 5) {
-                        top_field_first = buf[3] & (1 << 7);
-                        repeat_first_field = buf[3] & (1 << 1);
-                        progressive_frame = buf[4] & (1 << 7);
-                    
-                        /* check if we must repeat the frame */
-                        if (repeat_first_field) {
-                            if (pc->progressive_sequence) {
-                                if (top_field_first)
-                                    s->repeat_pict = 4;
-                                else
-                                    s->repeat_pict = 2;
-                            } else if (progressive_frame) {
-                                s->repeat_pict = 1;
-                            }
-                        }
-                    }
-                    break;
-                }
-            }
-            break;
-        case -1:
-            goto the_end;
-        default:
-            /* we stop parsing when we encounter a slice. It ensures
-               that this function takes a negligible amount of time */
-            if (start_code >= SLICE_MIN_START_CODE && 
-                start_code <= SLICE_MAX_START_CODE)
-                goto the_end;
-            break;
-        }
-    }
- the_end: ;
-}
-
-static int mpegvideo_parse(AVCodecParserContext *s,
-                           AVCodecContext *avctx,
-                           uint8_t **poutbuf, int *poutbuf_size, 
-                           const uint8_t *buf, int buf_size)
-{
-    ParseContext1 *pc1 = s->priv_data;
-    ParseContext *pc= &pc1->pc;
-    int next;
-    
-    next= ff_mpeg1_find_frame_end(pc, buf, buf_size);
-    
-    if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
-        *poutbuf = NULL;
-        *poutbuf_size = 0;
-        return buf_size;
-    }
-    /* we have a full frame : we just parse the first few MPEG headers
-       to have the full timing information. The time take by this
-       function should be negligible for uncorrupted streams */
-    mpegvideo_extract_headers(s, avctx, buf, buf_size);
-#if 0
-    printf("pict_type=%d frame_rate=%0.3f repeat_pict=%d\n", 
-           s->pict_type, (double)avctx->frame_rate / avctx->frame_rate_base, s->repeat_pict);
-#endif
-
-    *poutbuf = (uint8_t *)buf;
-    *poutbuf_size = buf_size;
-    return next;
-}
-
 void ff_parse_close(AVCodecParserContext *s)
 {
     ParseContext *pc = s->priv_data;
 
-    av_free(pc->buffer);
+    av_freep(&pc->buffer);
 }
 
-static void parse1_close(AVCodecParserContext *s)
+void ff_parse1_close(AVCodecParserContext *s)
 {
     ParseContext1 *pc1 = s->priv_data;
 
@@ -409,353 +334,16 @@ static void parse1_close(AVCodecParserContext *s)
 
 /*************************/
 
-/* used by parser */
-/* XXX: make it use less memory */
-static int av_mpeg4_decode_header(AVCodecParserContext *s1, 
-                                  AVCodecContext *avctx,
-                                  const uint8_t *buf, int buf_size)
-{
-    ParseContext1 *pc = s1->priv_data;
-    MpegEncContext *s = pc->enc;
-    GetBitContext gb1, *gb = &gb1;
-    int ret;
-
-    s->avctx = avctx;
-    s->current_picture_ptr = &s->current_picture;
-
-    if (avctx->extradata_size && pc->first_picture){
-        init_get_bits(gb, avctx->extradata, avctx->extradata_size*8);
-        ret = ff_mpeg4_decode_picture_header(s, gb);
-    }
-
-    init_get_bits(gb, buf, 8 * buf_size);
-    ret = ff_mpeg4_decode_picture_header(s, gb);
-    if (s->width) {
-        avctx->width = s->width;
-        avctx->height = s->height;
-    }
-    pc->first_picture = 0;
-    return ret;
-}
-
-static int mpeg4video_parse_init(AVCodecParserContext *s)
-{
-    ParseContext1 *pc = s->priv_data;
-
-    pc->enc = av_mallocz(sizeof(MpegEncContext));
-    if (!pc->enc)
-        return -1;
-    pc->first_picture = 1;
-    return 0;
-}
-
-static int mpeg4video_parse(AVCodecParserContext *s,
-                           AVCodecContext *avctx,
-                           uint8_t **poutbuf, int *poutbuf_size, 
+int ff_mpeg4video_split(AVCodecContext *avctx,
                            const uint8_t *buf, int buf_size)
 {
-    ParseContext *pc = s->priv_data;
-    int next;
-    
-    next= ff_mpeg4_find_frame_end(pc, buf, buf_size);
-
-    if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
-        *poutbuf = NULL;
-        *poutbuf_size = 0;
-        return buf_size;
-    }
-    av_mpeg4_decode_header(s, avctx, buf, buf_size);
-
-    *poutbuf = (uint8_t *)buf;
-    *poutbuf_size = buf_size;
-    return next;
-}
-
-/*************************/
-
-typedef struct MpegAudioParseContext {
-    uint8_t inbuf[MPA_MAX_CODED_FRAME_SIZE];   /* input buffer */
-    uint8_t *inbuf_ptr;
-    int frame_size;
-    int free_format_frame_size;
-    int free_format_next_header;
-} MpegAudioParseContext;
-
-#define MPA_HEADER_SIZE 4
-
-/* header + layer + bitrate + freq + lsf/mpeg25 */
-#define SAME_HEADER_MASK \
-   (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
-
-static int mpegaudio_parse_init(AVCodecParserContext *s1)
-{
-    MpegAudioParseContext *s = s1->priv_data;
-    s->inbuf_ptr = s->inbuf;
-    return 0;
-}
+    int i;
+    uint32_t state= -1;
 
-static int mpegaudio_parse(AVCodecParserContext *s1,
-                           AVCodecContext *avctx,
-                           uint8_t **poutbuf, int *poutbuf_size, 
-                           const uint8_t *buf, int buf_size)
-{
-    MpegAudioParseContext *s = s1->priv_data;
-    int len, ret;
-    uint32_t header;
-    const uint8_t *buf_ptr;
-
-    *poutbuf = NULL;
-    *poutbuf_size = 0;
-    buf_ptr = buf;
-    while (buf_size > 0) {
-       len = s->inbuf_ptr - s->inbuf;
-       if (s->frame_size == 0) {
-            /* special case for next header for first frame in free
-               format case (XXX: find a simpler method) */
-            if (s->free_format_next_header != 0) {
-                s->inbuf[0] = s->free_format_next_header >> 24;
-                s->inbuf[1] = s->free_format_next_header >> 16;
-                s->inbuf[2] = s->free_format_next_header >> 8;
-                s->inbuf[3] = s->free_format_next_header;
-                s->inbuf_ptr = s->inbuf + 4;
-                s->free_format_next_header = 0;
-                goto got_header;
-            }
-           /* no header seen : find one. We need at least MPA_HEADER_SIZE
-               bytes to parse it */
-           len = MPA_HEADER_SIZE - len;
-           if (len > buf_size)
-               len = buf_size;
-           if (len > 0) {
-               memcpy(s->inbuf_ptr, buf_ptr, len);
-               buf_ptr += len;
-               buf_size -= len;
-               s->inbuf_ptr += len;
-           }
-           if ((s->inbuf_ptr - s->inbuf) >= MPA_HEADER_SIZE) {
-            got_header:
-               header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
-                   (s->inbuf[2] << 8) | s->inbuf[3];
-
-                ret = mpa_decode_header(avctx, header);
-                if (ret < 0) {
-                   /* no sync found : move by one byte (inefficient, but simple!) */
-                   memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
-                   s->inbuf_ptr--;
-                    dprintf("skip %x\n", header);
-                    /* reset free format frame size to give a chance
-                       to get a new bitrate */
-                    s->free_format_frame_size = 0;
-               } else {
-                    s->frame_size = ret;
-#if 0
-                    /* free format: prepare to compute frame size */
-                   if (decode_header(s, header) == 1) {
-                       s->frame_size = -1;
-                    }
-#endif
-               }
-           }
-        } else 
-#if 0
-        if (s->frame_size == -1) {
-            /* free format : find next sync to compute frame size */
-           len = MPA_MAX_CODED_FRAME_SIZE - len;
-           if (len > buf_size)
-               len = buf_size;
-            if (len == 0) {
-               /* frame too long: resync */
-                s->frame_size = 0;
-               memmove(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
-               s->inbuf_ptr--;
-            } else {
-                uint8_t *p, *pend;
-                uint32_t header1;
-                int padding;
-
-                memcpy(s->inbuf_ptr, buf_ptr, len);
-                /* check for header */
-                p = s->inbuf_ptr - 3;
-                pend = s->inbuf_ptr + len - 4;
-                while (p <= pend) {
-                    header = (p[0] << 24) | (p[1] << 16) |
-                        (p[2] << 8) | p[3];
-                    header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
-                        (s->inbuf[2] << 8) | s->inbuf[3];
-                    /* check with high probability that we have a
-                       valid header */
-                    if ((header & SAME_HEADER_MASK) ==
-                        (header1 & SAME_HEADER_MASK)) {
-                        /* header found: update pointers */
-                        len = (p + 4) - s->inbuf_ptr;
-                        buf_ptr += len;
-                        buf_size -= len;
-                        s->inbuf_ptr = p;
-                        /* compute frame size */
-                        s->free_format_next_header = header;
-                        s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
-                        padding = (header1 >> 9) & 1;
-                        if (s->layer == 1)
-                            s->free_format_frame_size -= padding * 4;
-                        else
-                            s->free_format_frame_size -= padding;
-                        dprintf("free frame size=%d padding=%d\n", 
-                                s->free_format_frame_size, padding);
-                        decode_header(s, header1);
-                        goto next_data;
-                    }
-                    p++;
-                }
-                /* not found: simply increase pointers */
-                buf_ptr += len;
-                s->inbuf_ptr += len;
-                buf_size -= len;
-            }
-       } else 
-#endif
-        if (len < s->frame_size) {
-            if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
-                s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
-           len = s->frame_size - len;
-           if (len > buf_size)
-               len = buf_size;
-           memcpy(s->inbuf_ptr, buf_ptr, len);
-           buf_ptr += len;
-           s->inbuf_ptr += len;
-           buf_size -= len;
-       }
-        //    next_data:
-        if (s->frame_size > 0 && 
-            (s->inbuf_ptr - s->inbuf) >= s->frame_size) {
-            *poutbuf = s->inbuf;
-            *poutbuf_size = s->inbuf_ptr - s->inbuf;
-           s->inbuf_ptr = s->inbuf;
-           s->frame_size = 0;
-           break;
-       }
+    for(i=0; i<buf_size; i++){
+        state= (state<<8) | buf[i];
+        if(state == 0x1B3 || state == 0x1B6)
+            return i-3;
     }
-    return buf_ptr - buf;
-}
-
-#ifdef CONFIG_AC3
-extern int a52_syncinfo (const uint8_t * buf, int * flags,
-                         int * sample_rate, int * bit_rate);
-
-typedef struct AC3ParseContext {
-    uint8_t inbuf[4096]; /* input buffer */
-    uint8_t *inbuf_ptr;
-    int frame_size;
-    int flags;
-} AC3ParseContext;
-
-#define AC3_HEADER_SIZE 7
-#define A52_LFE 16
-
-static int ac3_parse_init(AVCodecParserContext *s1)
-{
-    AC3ParseContext *s = s1->priv_data;
-    s->inbuf_ptr = s->inbuf;
     return 0;
 }
-
-static int ac3_parse(AVCodecParserContext *s1,
-                     AVCodecContext *avctx,
-                     uint8_t **poutbuf, int *poutbuf_size, 
-                     const uint8_t *buf, int buf_size)
-{
-    AC3ParseContext *s = s1->priv_data;
-    const uint8_t *buf_ptr;
-    int len, sample_rate, bit_rate;
-    static const int ac3_channels[8] = {
-       2, 1, 2, 3, 3, 4, 4, 5
-    };
-
-    *poutbuf = NULL;
-    *poutbuf_size = 0;
-
-    buf_ptr = buf;
-    while (buf_size > 0) {
-        len = s->inbuf_ptr - s->inbuf;
-        if (s->frame_size == 0) {
-            /* no header seen : find one. We need at least 7 bytes to parse it */
-            len = AC3_HEADER_SIZE - len;
-            if (len > buf_size)
-                len = buf_size;
-            memcpy(s->inbuf_ptr, buf_ptr, len);
-            buf_ptr += len;
-            s->inbuf_ptr += len;
-            buf_size -= len;
-            if ((s->inbuf_ptr - s->inbuf) == AC3_HEADER_SIZE) {
-                len = a52_syncinfo(s->inbuf, &s->flags, &sample_rate, &bit_rate);
-                if (len == 0) {
-                    /* no sync found : move by one byte (inefficient, but simple!) */
-                    memmove(s->inbuf, s->inbuf + 1, AC3_HEADER_SIZE - 1);
-                    s->inbuf_ptr--;
-                } else {
-                   s->frame_size = len;
-                    /* update codec info */
-                    avctx->sample_rate = sample_rate;
-                    /* set channels,except if the user explicitly requests 1 or 2 channels, XXX/FIXME this is a bit ugly */
-                    if(avctx->channels!=1 && avctx->channels!=2){
-                        avctx->channels = ac3_channels[s->flags & 7];
-                        if (s->flags & A52_LFE)
-                            avctx->channels++;
-                    }
-                   avctx->bit_rate = bit_rate;
-                    avctx->frame_size = 6 * 256;
-                }
-            }
-        } else if (len < s->frame_size) {
-            len = s->frame_size - len;
-            if (len > buf_size)
-                len = buf_size;
-
-            memcpy(s->inbuf_ptr, buf_ptr, len);
-            buf_ptr += len;
-            s->inbuf_ptr += len;
-            buf_size -= len;
-        } else {
-            *poutbuf = s->inbuf;
-            *poutbuf_size = s->frame_size;
-            s->inbuf_ptr = s->inbuf;
-            s->frame_size = 0;
-            break;
-        }
-    }
-    return buf_ptr - buf;
-}
-#endif
-
-AVCodecParser mpegvideo_parser = {
-    { CODEC_ID_MPEG1VIDEO, CODEC_ID_MPEG2VIDEO },
-    sizeof(ParseContext1),
-    NULL,
-    mpegvideo_parse,
-    parse1_close,
-};
-
-AVCodecParser mpeg4video_parser = {
-    { CODEC_ID_MPEG4 },
-    sizeof(ParseContext1),
-    mpeg4video_parse_init,
-    mpeg4video_parse,
-    parse1_close,
-};
-
-AVCodecParser mpegaudio_parser = {
-    { CODEC_ID_MP2, CODEC_ID_MP3 },
-    sizeof(MpegAudioParseContext),
-    mpegaudio_parse_init,
-    mpegaudio_parse,
-    NULL,
-};
-
-#ifdef CONFIG_AC3
-AVCodecParser ac3_parser = {
-    { CODEC_ID_AC3 },
-    sizeof(AC3ParseContext),
-    ac3_parse_init,
-    ac3_parse,
-    NULL,
-};
-#endif