libavcodec/mdec.c

   1 /*
   2  * PSX MDEC codec
   3  * Copyright (c) 2003 Michael Niedermayer
   4  *
   5  * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 /**
  25  * @file mdec.c
  26  * PSX MDEC codec.
  27  * This is very similar to intra only MPEG1.
  28  */
  29
  30 #include "avcodec.h"
  31 #include "dsputil.h"
  32 #include "mpegvideo.h"
  33
  34 typedef struct MDECContext{
  35     AVCodecContext *avctx;
  36     DSPContext dsp;
  37     AVFrame picture;
  38     GetBitContext gb;
  39     ScanTable scantable;
  40     int version;
  41     int qscale;
  42     int last_dc[3];
  43     int mb_width;
  44     int mb_height;
  45     int mb_x, mb_y;
  46     DECLARE_ALIGNED_16(DCTELEM, block[6][64]);
  47     DECLARE_ALIGNED_8(uint16_t, intra_matrix[64]);
  48     DECLARE_ALIGNED_8(int, q_intra_matrix[64]);
  49     uint8_t *bitstream_buffer;
  50     unsigned int bitstream_buffer_size;
  51     int block_last_index[6];
  52 } MDECContext;
  53
  54 //very similar to mpeg1
  55 static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n)
  56 {
  57     int level, diff, i, j, run;
  58     int component;
  59     RLTable *rl = &ff_rl_mpeg1;
  60     uint8_t * const scantable= a->scantable.permutated;
  61     const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;
  62     const int qscale= a->qscale;
  63
  64     /* DC coef */
  65     if(a->version==2){
  66         block[0]= 2*get_sbits(&a->gb, 10) + 1024;
  67     }else{
  68         component = (n <= 3 ? 0 : n - 4 + 1);
  69         diff = decode_dc(&a->gb, component);
  70         if (diff >= 0xffff)
  71             return -1;
  72         a->last_dc[component]+= diff;
  73         block[0] = a->last_dc[component]<<3;
  74     }
  75
  76     i = 0;
  77     {
  78         OPEN_READER(re, &a->gb);
  79         /* now quantify & encode AC coefs */
  80         for(;;) {
  81             UPDATE_CACHE(re, &a->gb);
  82             GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
  83
  84             if(level == 127){
  85                 break;
  86             } else if(level != 0) {
  87                 i += run;
  88                 j = scantable[i];
  89                 level= (level*qscale*quant_matrix[j])>>3;
  90                 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
  91                 LAST_SKIP_BITS(re, &a->gb, 1);
  92             } else {
  93                 /* escape */
  94                 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
  95                 UPDATE_CACHE(re, &a->gb);
  96                 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
  97                 i += run;
  98                 j = scantable[i];
  99                 if(level<0){
 100                     level= -level;
 101                     level= (level*qscale*quant_matrix[j])>>3;
 102                     level= (level-1)|1;
 103                     level= -level;
 104                 }else{
 105                     level= (level*qscale*quant_matrix[j])>>3;
 106                     level= (level-1)|1;
 107                 }
 108             }
 109             if (i > 63){
 110                 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
 111                 return -1;
 112             }
 113
 114             block[j] = level;
 115         }
 116         CLOSE_READER(re, &a->gb);
 117     }
 118     a->block_last_index[n] = i;
 119     return 0;
 120 }
 121
 122 static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){
 123     int i;
 124     const int block_index[6]= {5,4,0,1,2,3};
 125
 126     a->dsp.clear_blocks(block[0]);
 127
 128     for(i=0; i<6; i++){
 129         if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0)
 130             return -1;
 131     }
 132     return 0;
 133 }
 134
 135 static inline void idct_put(MDECContext *a, int mb_x, int mb_y){
 136     DCTELEM (*block)[64]= a->block;
 137     int linesize= a->picture.linesize[0];
 138
 139     uint8_t *dest_y  = a->picture.data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
 140     uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
 141     uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;
 142
 143     a->dsp.idct_put(dest_y                 , linesize, block[0]);
 144     a->dsp.idct_put(dest_y              + 8, linesize, block[1]);
 145     a->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
 146     a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
 147
 148     if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
 149         a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
 150         a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
 151     }
 152 }
 153
 154 static int decode_frame(AVCodecContext *avctx,
 155                         void *data, int *data_size,
 156                         const uint8_t *buf, int buf_size)
 157 {
 158     MDECContext * const a = avctx->priv_data;
 159     AVFrame *picture = data;
 160     AVFrame * const p= &a->picture;
 161     int i;
 162
 163     if(p->data[0])
 164         avctx->release_buffer(avctx, p);
 165
 166     p->reference= 0;
 167     if(avctx->get_buffer(avctx, p) < 0){
 168         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 169         return -1;
 170     }
 171     p->pict_type= FF_I_TYPE;
 172     p->key_frame= 1;
 173
 174     a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
 175     for(i=0; i<buf_size; i+=2){
 176         a->bitstream_buffer[i]  = buf[i+1];
 177         a->bitstream_buffer[i+1]= buf[i  ];
 178     }
 179     init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);
 180
 181     /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
 182     skip_bits(&a->gb, 32);
 183
 184     a->qscale=  get_bits(&a->gb, 16);
 185     a->version= get_bits(&a->gb, 16);
 186
 187     a->last_dc[0]=
 188     a->last_dc[1]=
 189     a->last_dc[2]= 128;
 190
 191     for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){
 192         for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){
 193             if( decode_mb(a, a->block) <0)
 194                 return -1;
 195
 196             idct_put(a, a->mb_x, a->mb_y);
 197         }
 198     }
 199
 200     p->quality= a->qscale * FF_QP2LAMBDA;
 201     memset(p->qscale_table, a->qscale, p->qstride*a->mb_height);
 202
 203     *picture   = a->picture;
 204     *data_size = sizeof(AVPicture);
 205
 206     return (get_bits_count(&a->gb)+31)/32*4;
 207 }
 208
 209 static av_cold void mdec_common_init(AVCodecContext *avctx){
 210     MDECContext * const a = avctx->priv_data;
 211
 212     dsputil_init(&a->dsp, avctx);
 213
 214     a->mb_width   = (avctx->coded_width  + 15) / 16;
 215     a->mb_height  = (avctx->coded_height + 15) / 16;
 216
 217     avctx->coded_frame= &a->picture;
 218     a->avctx= avctx;
 219 }
 220
 221 static av_cold int decode_init(AVCodecContext *avctx){
 222     MDECContext * const a = avctx->priv_data;
 223     AVFrame *p= &a->picture;
 224
 225     mdec_common_init(avctx);
 226     init_vlcs();
 227     ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
 228
 229     p->qstride= a->mb_width;
 230     p->qscale_table= av_mallocz( p->qstride * a->mb_height);
 231     avctx->pix_fmt= PIX_FMT_YUV420P;
 232
 233     return 0;
 234 }
 235
 236 static av_cold int decode_end(AVCodecContext *avctx){
 237     MDECContext * const a = avctx->priv_data;
 238
 239     av_freep(&a->bitstream_buffer);
 240     av_freep(&a->picture.qscale_table);
 241     a->bitstream_buffer_size=0;
 242
 243     return 0;
 244 }
 245
 246 AVCodec mdec_decoder = {
 247     "mdec",
 248     CODEC_TYPE_VIDEO,
 249     CODEC_ID_MDEC,
 250     sizeof(MDECContext),
 251     decode_init,
 252     NULL,
 253     decode_end,
 254     decode_frame,
 255     CODEC_CAP_DR1,
 256     .long_name= NULL_IF_CONFIG_SMALL("Sony PlayStation MDEC (Motion DECoder)"),
 257 };
 258