libavcodec/rv40.c

   1 /*
   2  * RV40 decoder
   3  * Copyright (c) 2007 Konstantin Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file rv40.c
  24  * RV40 decoder
  25  */
  26
  27 #include "avcodec.h"
  28 #include "dsputil.h"
  29 #include "mpegvideo.h"
  30 #include "golomb.h"
  31
  32 #include "rv34.h"
  33 #include "rv40vlc2.h"
  34 #include "rv40data.h"
  35
  36 static VLC aic_top_vlc;
  37 static VLC aic_mode1_vlc[AIC_MODE1_NUM], aic_mode2_vlc[AIC_MODE2_NUM];
  38 static VLC ptype_vlc[NUM_PTYPE_VLCS], btype_vlc[NUM_BTYPE_VLCS];
  39
  40 /**
  41  * Initialize all tables.
  42  */
  43 static av_cold void rv40_init_tables()
  44 {
  45     int i;
  46
  47     init_vlc(&aic_top_vlc, AIC_TOP_BITS, AIC_TOP_SIZE,
  48              rv40_aic_top_vlc_bits,  1, 1,
  49              rv40_aic_top_vlc_codes, 1, 1, INIT_VLC_USE_STATIC);
  50     for(i = 0; i < AIC_MODE1_NUM; i++){
  51         // Every tenth VLC table is empty
  52         if((i % 10) == 9) continue;
  53         init_vlc(&aic_mode1_vlc[i], AIC_MODE1_BITS, AIC_MODE1_SIZE,
  54                  aic_mode1_vlc_bits[i],  1, 1,
  55                  aic_mode1_vlc_codes[i], 1, 1, INIT_VLC_USE_STATIC);
  56     }
  57     for(i = 0; i < AIC_MODE2_NUM; i++){
  58         init_vlc(&aic_mode2_vlc[i], AIC_MODE2_BITS, AIC_MODE2_SIZE,
  59                  aic_mode2_vlc_bits[i],  1, 1,
  60                  aic_mode2_vlc_codes[i], 2, 2, INIT_VLC_USE_STATIC);
  61     }
  62     for(i = 0; i < NUM_PTYPE_VLCS; i++)
  63          init_vlc_sparse(&ptype_vlc[i], PTYPE_VLC_BITS, PTYPE_VLC_SIZE,
  64                          ptype_vlc_bits[i],  1, 1,
  65                          ptype_vlc_codes[i], 1, 1,
  66                          ptype_vlc_syms,     1, 1, INIT_VLC_USE_STATIC);
  67     for(i = 0; i < NUM_BTYPE_VLCS; i++)
  68          init_vlc_sparse(&btype_vlc[i], BTYPE_VLC_BITS, BTYPE_VLC_SIZE,
  69                          btype_vlc_bits[i],  1, 1,
  70                          btype_vlc_codes[i], 1, 1,
  71                          btype_vlc_syms,     1, 1, INIT_VLC_USE_STATIC);
  72 }
  73
  74 /**
  75  * Get stored dimension from bitstream.
  76  *
  77  * If the width/height is the standard one then it's coded as a 3-bit index.
  78  * Otherwise it is coded as escaped 8-bit portions.
  79  */
  80 static int get_dimension(GetBitContext *gb, const int *dim)
  81 {
  82     int t   = get_bits(gb, 3);
  83     int val = dim[t];
  84     if(val < 0)
  85         val = dim[get_bits1(gb) - val];
  86     if(!val){
  87         do{
  88             t = get_bits(gb, 8);
  89             val += t << 2;
  90         }while(t == 0xFF);
  91     }
  92     return val;
  93 }
  94
  95 /**
  96  * Get encoded picture size - usually this is called from rv40_parse_slice_header.
  97  */
  98 static void rv40_parse_picture_size(GetBitContext *gb, int *w, int *h)
  99 {
 100     *w = get_dimension(gb, rv40_standard_widths);
 101     *h = get_dimension(gb, rv40_standard_heights);
 102 }
 103
 104 static int rv40_parse_slice_header(RV34DecContext *r, GetBitContext *gb, SliceInfo *si)
 105 {
 106     int mb_bits;
 107     int w = r->s.width, h = r->s.height;
 108     int mb_size;
 109
 110     memset(si, 0, sizeof(SliceInfo));
 111     if(get_bits1(gb))
 112         return -1;
 113     si->type = get_bits(gb, 2);
 114     if(si->type == 1) si->type = 0;
 115     si->quant = get_bits(gb, 5);
 116     if(get_bits(gb, 2))
 117         return -1;
 118     si->vlc_set = get_bits(gb, 2);
 119     skip_bits1(gb);
 120     si->pts = get_bits(gb, 13);
 121     if(!si->type || !get_bits1(gb))
 122         rv40_parse_picture_size(gb, &w, &h);
 123     if(avcodec_check_dimensions(r->s.avctx, w, h) < 0)
 124         return -1;
 125     si->width  = w;
 126     si->height = h;
 127     mb_size = ((w + 15) >> 4) * ((h + 15) >> 4);
 128     mb_bits = ff_rv34_get_start_offset(gb, mb_size);
 129     si->start = get_bits(gb, mb_bits);
 130
 131     return 0;
 132 }
 133
 134 /**
 135  * Decode 4x4 intra types array.
 136  */
 137 static int rv40_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst)
 138 {
 139     MpegEncContext *s = &r->s;
 140     int i, j, k, v;
 141     int A, B, C;
 142     int pattern;
 143     int8_t *ptr;
 144
 145     for(i = 0; i < 4; i++, dst += s->b4_stride){
 146         if(!i && s->first_slice_line){
 147             pattern = get_vlc2(gb, aic_top_vlc.table, AIC_TOP_BITS, 1);
 148             dst[0] = (pattern >> 2) & 2;
 149             dst[1] = (pattern >> 1) & 2;
 150             dst[2] =  pattern       & 2;
 151             dst[3] = (pattern << 1) & 2;
 152             continue;
 153         }
 154         ptr = dst;
 155         for(j = 0; j < 4; j++){
 156             /* Coefficients are read using VLC chosen by the prediction pattern
 157              * The first one (used for retrieving a pair of coefficients) is
 158              * constructed from the top, top right and left coefficients
 159              * The second one (used for retrieving only one coefficient) is
 160              * top + 10 * left.
 161              */
 162             A = ptr[-s->b4_stride + 1]; // it won't be used for the last coefficient in a row
 163             B = ptr[-s->b4_stride];
 164             C = ptr[-1];
 165             pattern = A + (B << 4) + (C << 8);
 166             for(k = 0; k < MODE2_PATTERNS_NUM; k++)
 167                 if(pattern == rv40_aic_table_index[k])
 168                     break;
 169             if(j < 3 && k < MODE2_PATTERNS_NUM){ //pattern is found, decoding 2 coefficients
 170                 v = get_vlc2(gb, aic_mode2_vlc[k].table, AIC_MODE2_BITS, 2);
 171                 *ptr++ = v/9;
 172                 *ptr++ = v%9;
 173                 j++;
 174             }else{
 175                 if(B != -1 && C != -1)
 176                     v = get_vlc2(gb, aic_mode1_vlc[B + C*10].table, AIC_MODE1_BITS, 1);
 177                 else{ // tricky decoding
 178                     v = 0;
 179                     switch(C){
 180                     case -1: // code 0 -> 1, 1 -> 0
 181                         if(B < 2)
 182                             v = get_bits1(gb) ^ 1;
 183                         break;
 184                     case  0:
 185                     case  2: // code 0 -> 2, 1 -> 0
 186                         v = (get_bits1(gb) ^ 1) << 1;
 187                         break;
 188                     }
 189                 }
 190                 *ptr++ = v;
 191             }
 192         }
 193     }
 194     return 0;
 195 }
 196
 197 /**
 198  * Decode macroblock information.
 199  */
 200 static int rv40_decode_mb_info(RV34DecContext *r)
 201 {
 202     MpegEncContext *s = &r->s;
 203     GetBitContext *gb = &s->gb;
 204     int q, i;
 205     int prev_type = 0;
 206     int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
 207     int blocks[RV34_MB_TYPES] = {0};
 208     int count = 0;
 209
 210     if(!r->s.mb_skip_run)
 211         r->s.mb_skip_run = svq3_get_ue_golomb(gb) + 1;
 212
 213     if(--r->s.mb_skip_run)
 214          return RV34_MB_SKIP;
 215
 216     if(r->avail_cache[5-1])
 217         blocks[r->mb_type[mb_pos - 1]]++;
 218     if(r->avail_cache[5-4]){
 219         blocks[r->mb_type[mb_pos - s->mb_stride]]++;
 220         if(r->avail_cache[5-2])
 221             blocks[r->mb_type[mb_pos - s->mb_stride + 1]]++;
 222         if(r->avail_cache[5-5])
 223             blocks[r->mb_type[mb_pos - s->mb_stride - 1]]++;
 224     }
 225
 226     for(i = 0; i < RV34_MB_TYPES; i++){
 227         if(blocks[i] > count){
 228             count = blocks[i];
 229             prev_type = i;
 230         }
 231     }
 232     if(s->pict_type == FF_P_TYPE){
 233         prev_type = block_num_to_ptype_vlc_num[prev_type];
 234         q = get_vlc2(gb, ptype_vlc[prev_type].table, PTYPE_VLC_BITS, 1);
 235         if(q < PBTYPE_ESCAPE)
 236             return q;
 237         q = get_vlc2(gb, ptype_vlc[prev_type].table, PTYPE_VLC_BITS, 1);
 238         av_log(s->avctx, AV_LOG_ERROR, "Dquant for P-frame\n");
 239     }else{
 240         prev_type = block_num_to_btype_vlc_num[prev_type];
 241         q = get_vlc2(gb, btype_vlc[prev_type].table, BTYPE_VLC_BITS, 1);
 242         if(q < PBTYPE_ESCAPE)
 243             return q;
 244         q = get_vlc2(gb, btype_vlc[prev_type].table, BTYPE_VLC_BITS, 1);
 245         av_log(s->avctx, AV_LOG_ERROR, "Dquant for B-frame\n");
 246     }
 247     return 0;
 248 }
 249
 250 /**
 251  * Initialize decoder.
 252  */
 253 static av_cold int rv40_decode_init(AVCodecContext *avctx)
 254 {
 255     RV34DecContext *r = avctx->priv_data;
 256
 257     r->rv30 = 0;
 258     ff_rv34_decode_init(avctx);
 259     if(!aic_top_vlc.bits)
 260         rv40_init_tables();
 261     r->parse_slice_header = rv40_parse_slice_header;
 262     r->decode_intra_types = rv40_decode_intra_types;
 263     r->decode_mb_info     = rv40_decode_mb_info;
 264     r->luma_dc_quant_i = rv40_luma_dc_quant[0];
 265     r->luma_dc_quant_p = rv40_luma_dc_quant[1];
 266     return 0;
 267 }
 268
 269 AVCodec rv40_decoder = {
 270     "rv40",
 271     CODEC_TYPE_VIDEO,
 272     CODEC_ID_RV40,
 273     sizeof(RV34DecContext),
 274     rv40_decode_init,
 275     NULL,
 276     ff_rv34_decode_end,
 277     ff_rv34_decode_frame,
 278     CODEC_CAP_DR1 | CODEC_CAP_DELAY,
 279     .long_name = NULL_IF_CONFIG_SMALL("RealVideo 4.0"),
 280 };