libavcodec/mdec.c

   1 /*
   2  * PSX MDEC codec
   3  * Copyright (c) 2003 Michael Niedermayer
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>
  20  */
  21
  22 /**
  23  * @file mdec.c
  24  * PSX MDEC codec.
  25  * This is very similar to intra only MPEG1.
  26  */
  27
  28 #include "avcodec.h"
  29 #include "dsputil.h"
  30 #include "mpegvideo.h"
  31
  32 //#undef NDEBUG
  33 //#include <assert.h>
  34
  35 typedef struct MDECContext{
  36     AVCodecContext *avctx;
  37     DSPContext dsp;
  38     AVFrame picture;
  39     PutBitContext pb;
  40     GetBitContext gb;
  41     ScanTable scantable;
  42     int version;
  43     int qscale;
  44     int last_dc[3];
  45     int mb_width;
  46     int mb_height;
  47     int mb_x, mb_y;
  48     DCTELEM __align8 block[6][64];
  49     uint16_t __align8 intra_matrix[64];
  50     int __align8 q_intra_matrix[64];
  51     uint8_t *bitstream_buffer;
  52     int bitstream_buffer_size;
  53     int block_last_index[6];
  54 } MDECContext;
  55
  56 //very similar to mpeg1
  57 static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n)
  58 {
  59     int level, diff, i, j, run;
  60     int component;
  61     RLTable *rl = &rl_mpeg1;
  62     uint8_t * const scantable= a->scantable.permutated;
  63     const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;
  64     const int qscale= a->qscale;
  65
  66     /* DC coef */
  67     if(a->version==2){
  68         block[0]= 2*get_sbits(&a->gb, 10) + 1024;
  69     }else{
  70         component = (n <= 3 ? 0 : n - 4 + 1);
  71         diff = decode_dc(&a->gb, component);
  72         if (diff >= 0xffff)
  73             return -1;
  74         a->last_dc[component]+= diff;
  75         block[0] = a->last_dc[component]<<3;
  76     }
  77
  78     i = 0;
  79     {
  80         OPEN_READER(re, &a->gb);
  81         /* now quantify & encode AC coefs */
  82         for(;;) {
  83             UPDATE_CACHE(re, &a->gb);
  84             GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
  85
  86             if(level == 127){
  87                 break;
  88             } else if(level != 0) {
  89                 i += run;
  90                 j = scantable[i];
  91                 level= (level*qscale*quant_matrix[j])>>3;
  92 //                level= (level-1)|1;
  93                 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
  94                 LAST_SKIP_BITS(re, &a->gb, 1);
  95             } else {
  96                 /* escape */
  97                 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
  98                 UPDATE_CACHE(re, &a->gb);
  99                 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
 100                 i += run;
 101                 j = scantable[i];
 102                 if(level<0){
 103                     level= -level;
 104                     level= (level*qscale*quant_matrix[j])>>3;
 105                     level= (level-1)|1;
 106                     level= -level;
 107                 }else{
 108                     level= (level*qscale*quant_matrix[j])>>3;
 109                     level= (level-1)|1;
 110                 }
 111             }
 112             if (i > 63){
 113                 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
 114                 return -1;
 115             }
 116
 117             block[j] = level;
 118         }
 119         CLOSE_READER(re, &a->gb);
 120     }
 121     a->block_last_index[n] = i;
 122     return 0;
 123 }
 124
 125 static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){
 126     int i;
 127     const int block_index[6]= {5,4,0,1,2,3};
 128
 129     a->dsp.clear_blocks(block[0]);
 130
 131     for(i=0; i<6; i++){
 132         if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0)
 133             return -1;
 134     }
 135     return 0;
 136 }
 137
 138 static inline void idct_put(MDECContext *a, int mb_x, int mb_y){
 139     DCTELEM (*block)[64]= a->block;
 140     int linesize= a->picture.linesize[0];
 141
 142     uint8_t *dest_y  = a->picture.data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
 143     uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
 144     uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;
 145
 146     a->dsp.idct_put(dest_y                 , linesize, block[0]);
 147     a->dsp.idct_put(dest_y              + 8, linesize, block[1]);
 148     a->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
 149     a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
 150
 151     if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
 152         a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
 153         a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
 154     }
 155 }
 156
 157 static int decode_frame(AVCodecContext *avctx,
 158                         void *data, int *data_size,
 159                         uint8_t *buf, int buf_size)
 160 {
 161     MDECContext * const a = avctx->priv_data;
 162     AVFrame *picture = data;
 163     AVFrame * const p= (AVFrame*)&a->picture;
 164     int i;
 165
 166     /* special case for last picture */
 167     if (buf_size == 0) {
 168         return 0;
 169     }
 170
 171     if(p->data[0])
 172         avctx->release_buffer(avctx, p);
 173
 174     p->reference= 0;
 175     if(avctx->get_buffer(avctx, p) < 0){
 176         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 177         return -1;
 178     }
 179     p->pict_type= I_TYPE;
 180     p->key_frame= 1;
 181     a->last_dc[0]=
 182     a->last_dc[1]=
 183     a->last_dc[2]= 0;
 184
 185     a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
 186     for(i=0; i<buf_size; i+=2){
 187         a->bitstream_buffer[i]  = buf[i+1];
 188         a->bitstream_buffer[i+1]= buf[i  ];
 189     }
 190     init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);
 191
 192     /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
 193     skip_bits(&a->gb, 32);
 194
 195     a->qscale=  get_bits(&a->gb, 16);
 196     a->version= get_bits(&a->gb, 16);
 197
 198 //    printf("qscale:%d (0x%X), version:%d (0x%X)\n", a->qscale, a->qscale, a->version, a->version);
 199
 200     for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){
 201         for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){
 202             if( decode_mb(a, a->block) <0)
 203                 return -1;
 204
 205             idct_put(a, a->mb_x, a->mb_y);
 206         }
 207     }
 208
 209 //    p->quality= (32 + a->inv_qscale/2)/a->inv_qscale;
 210 //    memset(p->qscale_table, p->quality, p->qstride*a->mb_height);
 211
 212     *picture= *(AVFrame*)&a->picture;
 213     *data_size = sizeof(AVPicture);
 214
 215     emms_c();
 216
 217     return (get_bits_count(&a->gb)+31)/32*4;
 218 }
 219
 220 static void mdec_common_init(AVCodecContext *avctx){
 221     MDECContext * const a = avctx->priv_data;
 222
 223     dsputil_init(&a->dsp, avctx);
 224
 225     a->mb_width   = (avctx->coded_width  + 15) / 16;
 226     a->mb_height  = (avctx->coded_height + 15) / 16;
 227
 228     avctx->coded_frame= (AVFrame*)&a->picture;
 229     a->avctx= avctx;
 230 }
 231
 232 static int decode_init(AVCodecContext *avctx){
 233     MDECContext * const a = avctx->priv_data;
 234     AVFrame *p= (AVFrame*)&a->picture;
 235
 236     mdec_common_init(avctx);
 237     init_vlcs();
 238     ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
 239 /*
 240     for(i=0; i<64; i++){
 241         int index= ff_zigzag_direct[i];
 242         a->intra_matrix[i]= 64*ff_mpeg1_default_intra_matrix[index] / a->inv_qscale;
 243     }
 244 */
 245     p->qstride= a->mb_width;
 246     p->qscale_table= av_mallocz( p->qstride * a->mb_height);
 247
 248     return 0;
 249 }
 250
 251 static int decode_end(AVCodecContext *avctx){
 252     MDECContext * const a = avctx->priv_data;
 253
 254     av_freep(&a->bitstream_buffer);
 255     av_freep(&a->picture.qscale_table);
 256     a->bitstream_buffer_size=0;
 257
 258     return 0;
 259 }
 260
 261 AVCodec mdec_decoder = {
 262     "mdec",
 263     CODEC_TYPE_VIDEO,
 264     CODEC_ID_MDEC,
 265     sizeof(MDECContext),
 266     decode_init,
 267     NULL,
 268     decode_end,
 269     decode_frame,
 270     CODEC_CAP_DR1,
 271 };
 272