RV40 decoder specific functions
authorKostya Shishkov <kostya.shishkov@gmail.com>
Tue, 4 Dec 2007 17:41:46 +0000 (17:41 +0000)
committerKostya Shishkov <kostya.shishkov@gmail.com>
Tue, 4 Dec 2007 17:41:46 +0000 (17:41 +0000)
Originally committed as revision 11163 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/rv40.c [new file with mode: 0644]

diff --git a/libavcodec/rv40.c b/libavcodec/rv40.c
new file mode 100644 (file)
index 0000000..791ed17
--- /dev/null
@@ -0,0 +1,275 @@
+/*
+ * RV40 decoder
+ * Copyright (c) 2007 Konstantin Shishkov
+ *
+ * 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 2.1 of the License, or (at your option) any later version.
+ *
+ * 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file rv40.c
+ * RV40 decoder
+ */
+
+#include "avcodec.h"
+#include "dsputil.h"
+#include "mpegvideo.h"
+
+#include "rv34.h"
+#include "rv40vlc2.h"
+#include "rv40data.h"
+
+static VLC aic_top_vlc;
+static VLC aic_mode1_vlc[AIC_MODE1_NUM], aic_mode2_vlc[AIC_MODE2_NUM];
+static VLC ptype_vlc[NUM_PTYPE_VLCS], btype_vlc[NUM_BTYPE_VLCS];
+
+/**
+ * Initialize all tables.
+ */
+static void rv40_init_tables()
+{
+    int i;
+
+    init_vlc(&aic_top_vlc, AIC_TOP_BITS, AIC_TOP_SIZE,
+             rv40_aic_top_vlc_bits,  1, 1,
+             rv40_aic_top_vlc_codes, 1, 1, INIT_VLC_USE_STATIC);
+    for(i = 0; i < AIC_MODE1_NUM; i++){
+        // Every tenth VLC table is empty
+        if((i % 10) == 9) continue;
+        init_vlc(&aic_mode1_vlc[i], AIC_MODE1_BITS, AIC_MODE1_SIZE,
+                 aic_mode1_vlc_bits[i],  1, 1,
+                 aic_mode1_vlc_codes[i], 1, 1, INIT_VLC_USE_STATIC);
+    }
+    for(i = 0; i < AIC_MODE2_NUM; i++){
+        init_vlc(&aic_mode2_vlc[i], AIC_MODE2_BITS, AIC_MODE2_SIZE,
+                 aic_mode2_vlc_bits[i],  1, 1,
+                 aic_mode2_vlc_codes[i], 2, 2, INIT_VLC_USE_STATIC);
+    }
+    for(i = 0; i < NUM_PTYPE_VLCS; i++)
+         init_vlc_sparse(&ptype_vlc[i], PTYPE_VLC_BITS, PTYPE_VLC_SIZE,
+                         ptype_vlc_bits[i],  1, 1,
+                         ptype_vlc_codes[i], 1, 1,
+                         ptype_vlc_syms,     1, 1, INIT_VLC_USE_STATIC);
+    for(i = 0; i < NUM_BTYPE_VLCS; i++)
+         init_vlc_sparse(&btype_vlc[i], BTYPE_VLC_BITS, BTYPE_VLC_SIZE,
+                         btype_vlc_bits[i],  1, 1,
+                         btype_vlc_codes[i], 1, 1,
+                         btype_vlc_syms,     1, 1, INIT_VLC_USE_STATIC);
+}
+
+/**
+ * Get stored dimension from bitstream.
+ *
+ * If the width/height is the standard one then it's coded as a 3-bit index.
+ * Otherwise it is coded as escaped 8-bit portions.
+ */
+static int get_dimension(GetBitContext *gb, const int *dim)
+{
+    int t   = get_bits(gb, 3);
+    int val = dim[t];
+    if(val < 0)
+        val = dim[get_bits1(gb) - val];
+    if(!val){
+        do{
+            t = get_bits(gb, 8);
+            val += t << 2;
+        }while(t == 0xFF);
+    }
+    return val;
+}
+
+/**
+ * Get encoded picture size - usually this is called from rv40_parse_slice_header.
+ */
+static void rv40_parse_picture_size(GetBitContext *gb, int *w, int *h)
+{
+    *w = get_dimension(gb, rv40_standard_widths);
+    *h = get_dimension(gb, rv40_standard_heights);
+}
+
+static int rv40_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
+{
+    int t, mb_bits;
+    int w = r->s.width, h = r->s.height;
+    int mb_size;
+
+    memset(si, 0, sizeof(SliceInfo));
+    if(get_bits1(gb))
+        return -1;
+    si->type = get_bits(gb, 2);
+    if(si->type == 1) si->type = 0;
+    si->quant = get_bits(gb, 5);
+    if(get_bits(gb, 2))
+        return -1;
+    si->vlc_set = get_bits(gb, 2);
+    skip_bits1(gb);
+    t = get_bits(gb, 13); /// ???
+    if(!si->type || !get_bits1(gb))
+        rv40_parse_picture_size(gb, &w, &h);
+    si->width  = w;
+    si->height = h;
+    mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
+    mb_bits = ff_rv34_get_start_offset(gb, mb_size);
+    si->start = get_bits(gb, mb_bits);
+
+    return 0;
+}
+
+/**
+ * Decode 4x4 intra types array.
+ */
+static int rv40_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int *dst)
+{
+    MpegEncContext *s = &r->s;
+    int i, j, k, v;
+    int A, B, C;
+    int pattern;
+    int *ptr;
+
+    for(i = 0; i < 4; i++, dst += s->b4_stride){
+        if(!i && s->first_slice_line){
+            pattern = get_vlc2(gb, aic_top_vlc.table, AIC_TOP_BITS, 1);
+            dst[0] = (pattern >> 2) & 2;
+            dst[1] = (pattern >> 1) & 2;
+            dst[2] =  pattern       & 2;
+            dst[3] = (pattern << 1) & 2;
+            continue;
+        }
+        ptr = dst;
+        for(j = 0; j < 4; j++){
+            /* Coefficients are read using VLC chosen by the prediction pattern
+             * The first one (used for retrieving a pair of coefficients) is
+             * constructed from the top, top right and left coefficients
+             * The second one (used for retrieving only one coefficient) is
+             * top + 10 * left.
+             */
+            A = ptr[-s->b4_stride + 1]; // it won't be used for the last coefficient in a row
+            B = ptr[-s->b4_stride];
+            C = ptr[-1];
+            pattern = A + (B << 4) + (C << 8);
+            for(k = 0; k < MODE2_PATTERNS_NUM; k++)
+                if(pattern == rv40_aic_table_index[k])
+                    break;
+            if(j < 3 && k < MODE2_PATTERNS_NUM){ //pattern is found, decoding 2 coefficients
+                v = get_vlc2(gb, aic_mode2_vlc[k].table, AIC_MODE2_BITS, 2);
+                *ptr++ = v/9;
+                *ptr++ = v%9;
+                j++;
+            }else{
+                if(B != -1 && C != -1)
+                    v = get_vlc2(gb, aic_mode1_vlc[B + C*10].table, AIC_MODE1_BITS, 1);
+                else{ // tricky decoding
+                    v = 0;
+                    switch(C){
+                    case -1: // code 0 -> 1, 1 -> 0
+                        if(B < 2)
+                            v = get_bits1(gb) ^ 1;
+                        break;
+                    case  0:
+                    case  2: // code 0 -> 2, 1 -> 0
+                        v = (get_bits1(gb) ^ 1) << 1;
+                        break;
+                    }
+                }
+                *ptr++ = v;
+            }
+        }
+    }
+    return 0;
+}
+
+/**
+ * Decode macroblock information.
+ */
+static int rv40_decode_mb_info(RV34DecContext *r)
+{
+    MpegEncContext *s = &r->s;
+    GetBitContext *gb = &s->gb;
+    int q, i;
+    int prev_type = 0;
+    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
+    int blocks[RV34_MB_TYPES] = {0};
+    int count = 0;
+
+    if(!r->s.mb_skip_run)
+        r->s.mb_skip_run = ff_rv34_get_gamma(gb);
+
+    if(--r->s.mb_skip_run)
+         return RV34_MB_SKIP;
+
+    if(r->avail[0])
+        blocks[r->mb_type[mb_pos - 1]]++;
+    if(r->avail[1]){
+        blocks[r->mb_type[mb_pos - s->mb_stride]]++;
+        if(r->avail[2])
+            blocks[r->mb_type[mb_pos - s->mb_stride + 1]]++;
+        if(r->avail[3])
+            blocks[r->mb_type[mb_pos - s->mb_stride - 1]]++;
+    }
+
+    for(i = 0; i < RV34_MB_TYPES; i++){
+        if(blocks[i] > count){
+            count = blocks[i];
+            prev_type = i;
+        }
+    }
+    if(s->pict_type == P_TYPE){
+        prev_type = block_num_to_ptype_vlc_num[prev_type];
+        q = get_vlc2(gb, ptype_vlc[prev_type].table, PTYPE_VLC_BITS, 1);
+        if(q < PBTYPE_ESCAPE)
+            return q;
+        q = get_vlc2(gb, ptype_vlc[prev_type].table, PTYPE_VLC_BITS, 1);
+        av_log(s->avctx, AV_LOG_ERROR, "Dquant for P-frame\n");
+    }else{
+        prev_type = block_num_to_btype_vlc_num[prev_type];
+        q = get_vlc2(gb, btype_vlc[prev_type].table, BTYPE_VLC_BITS, 1);
+        if(q < PBTYPE_ESCAPE)
+            return q;
+        q = get_vlc2(gb, btype_vlc[prev_type].table, BTYPE_VLC_BITS, 1);
+        av_log(s->avctx, AV_LOG_ERROR, "Dquant for B-frame\n");
+    }
+    return 0;
+}
+
+/**
+ * Initialize decoder.
+ */
+static int rv40_decode_init(AVCodecContext *avctx)
+{
+    RV34DecContext *r = avctx->priv_data;
+
+    r->rv30 = 0;
+    ff_rv34_decode_init(avctx);
+    if(!aic_top_vlc.bits)
+        rv40_init_tables();
+    r->parse_slice_header = rv40_parse_slice_header;
+    r->decode_intra_types = rv40_decode_intra_types;
+    r->decode_mb_info     = rv40_decode_mb_info;
+    r->luma_dc_quant_i = rv40_luma_dc_quant[0];
+    r->luma_dc_quant_p = rv40_luma_dc_quant[1];
+    return 0;
+}
+
+AVCodec rv40_decoder = {
+    "rv40",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_RV40,
+    sizeof(RV34DecContext),
+    rv40_decode_init,
+    NULL,
+    ff_rv34_decode_end,
+    ff_rv34_decode_frame,
+};