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 //#undef NDEBUG
  35 //#include <assert.h>
  36
  37 typedef struct MDECContext{
  38     AVCodecContext *avctx;
  39     DSPContext dsp;
  40     AVFrame picture;
  41     PutBitContext pb;
  42     GetBitContext gb;
  43     ScanTable scantable;
  44     int version;
  45     int qscale;
  46     int last_dc[3];
  47     int mb_width;
  48     int mb_height;
  49     int mb_x, mb_y;
  50     DECLARE_ALIGNED_8(DCTELEM, block[6][64]);
  51     DECLARE_ALIGNED_8(uint16_t, intra_matrix[64]);
  52     DECLARE_ALIGNED_8(int, q_intra_matrix[64]);
  53     uint8_t *bitstream_buffer;
  54     unsigned int bitstream_buffer_size;
  55     int block_last_index[6];
  56 } MDECContext;
  57
  58 //very similar to mpeg1
  59 static inline int mdec_decode_block_intra(MDECContext *a, DCTELEM *block, int n)
  60 {
  61     int level, diff, i, j, run;
  62     int component;
  63     RLTable *rl = &ff_rl_mpeg1;
  64     uint8_t * const scantable= a->scantable.permutated;
  65     const uint16_t *quant_matrix= ff_mpeg1_default_intra_matrix;
  66     const int qscale= a->qscale;
  67
  68     /* DC coef */
  69     if(a->version==2){
  70         block[0]= 2*get_sbits(&a->gb, 10) + 1024;
  71     }else{
  72         component = (n <= 3 ? 0 : n - 4 + 1);
  73         diff = decode_dc(&a->gb, component);
  74         if (diff >= 0xffff)
  75             return -1;
  76         a->last_dc[component]+= diff;
  77         block[0] = a->last_dc[component]<<3;
  78     }
  79
  80     i = 0;
  81     {
  82         OPEN_READER(re, &a->gb);
  83         /* now quantify & encode AC coefs */
  84         for(;;) {
  85             UPDATE_CACHE(re, &a->gb);
  86             GET_RL_VLC(level, run, re, &a->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
  87
  88             if(level == 127){
  89                 break;
  90             } else if(level != 0) {
  91                 i += run;
  92                 j = scantable[i];
  93                 level= (level*qscale*quant_matrix[j])>>3;
  94 //                level= (level-1)|1;
  95                 level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);
  96                 LAST_SKIP_BITS(re, &a->gb, 1);
  97             } else {
  98                 /* escape */
  99                 run = SHOW_UBITS(re, &a->gb, 6)+1; LAST_SKIP_BITS(re, &a->gb, 6);
 100                 UPDATE_CACHE(re, &a->gb);
 101                 level = SHOW_SBITS(re, &a->gb, 10); SKIP_BITS(re, &a->gb, 10);
 102                 i += run;
 103                 j = scantable[i];
 104                 if(level<0){
 105                     level= -level;
 106                     level= (level*qscale*quant_matrix[j])>>3;
 107                     level= (level-1)|1;
 108                     level= -level;
 109                 }else{
 110                     level= (level*qscale*quant_matrix[j])>>3;
 111                     level= (level-1)|1;
 112                 }
 113             }
 114             if (i > 63){
 115                 av_log(a->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);
 116                 return -1;
 117             }
 118
 119             block[j] = level;
 120         }
 121         CLOSE_READER(re, &a->gb);
 122     }
 123     a->block_last_index[n] = i;
 124     return 0;
 125 }
 126
 127 static inline int decode_mb(MDECContext *a, DCTELEM block[6][64]){
 128     int i;
 129     const int block_index[6]= {5,4,0,1,2,3};
 130
 131     a->dsp.clear_blocks(block[0]);
 132
 133     for(i=0; i<6; i++){
 134         if( mdec_decode_block_intra(a, block[ block_index[i] ], block_index[i]) < 0)
 135             return -1;
 136     }
 137     return 0;
 138 }
 139
 140 static inline void idct_put(MDECContext *a, int mb_x, int mb_y){
 141     DCTELEM (*block)[64]= a->block;
 142     int linesize= a->picture.linesize[0];
 143
 144     uint8_t *dest_y  = a->picture.data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
 145     uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
 146     uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;
 147
 148     a->dsp.idct_put(dest_y                 , linesize, block[0]);
 149     a->dsp.idct_put(dest_y              + 8, linesize, block[1]);
 150     a->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
 151     a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);
 152
 153     if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
 154         a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
 155         a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
 156     }
 157 }
 158
 159 static int decode_frame(AVCodecContext *avctx,
 160                         void *data, int *data_size,
 161                         const uint8_t *buf, int buf_size)
 162 {
 163     MDECContext * const a = avctx->priv_data;
 164     AVFrame *picture = data;
 165     AVFrame * const p= (AVFrame*)&a->picture;
 166     int i;
 167
 168     if(p->data[0])
 169         avctx->release_buffer(avctx, p);
 170
 171     p->reference= 0;
 172     if(avctx->get_buffer(avctx, p) < 0){
 173         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 174         return -1;
 175     }
 176     p->pict_type= FF_I_TYPE;
 177     p->key_frame= 1;
 178
 179     a->bitstream_buffer= av_fast_realloc(a->bitstream_buffer, &a->bitstream_buffer_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
 180     for(i=0; i<buf_size; i+=2){
 181         a->bitstream_buffer[i]  = buf[i+1];
 182         a->bitstream_buffer[i+1]= buf[i  ];
 183     }
 184     init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);
 185
 186     /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */
 187     skip_bits(&a->gb, 32);
 188
 189     a->qscale=  get_bits(&a->gb, 16);
 190     a->version= get_bits(&a->gb, 16);
 191
 192     a->last_dc[0]=
 193     a->last_dc[1]=
 194     a->last_dc[2]= 128;
 195
 196 //    printf("qscale:%d (0x%X), version:%d (0x%X)\n", a->qscale, a->qscale, a->version, a->version);
 197
 198     for(a->mb_x=0; a->mb_x<a->mb_width; a->mb_x++){
 199         for(a->mb_y=0; a->mb_y<a->mb_height; a->mb_y++){
 200             if( decode_mb(a, a->block) <0)
 201                 return -1;
 202
 203             idct_put(a, a->mb_x, a->mb_y);
 204         }
 205     }
 206
 207 //    p->quality= (32 + a->inv_qscale/2)/a->inv_qscale;
 208 //    memset(p->qscale_table, p->quality, p->qstride*a->mb_height);
 209
 210     *picture= *(AVFrame*)&a->picture;
 211     *data_size = sizeof(AVPicture);
 212
 213     emms_c();
 214
 215     return (get_bits_count(&a->gb)+31)/32*4;
 216 }
 217
 218 static av_cold void mdec_common_init(AVCodecContext *avctx){
 219     MDECContext * const a = avctx->priv_data;
 220
 221     dsputil_init(&a->dsp, avctx);
 222
 223     a->mb_width   = (avctx->coded_width  + 15) / 16;
 224     a->mb_height  = (avctx->coded_height + 15) / 16;
 225
 226     avctx->coded_frame= (AVFrame*)&a->picture;
 227     a->avctx= avctx;
 228 }
 229
 230 static av_cold int decode_init(AVCodecContext *avctx){
 231     MDECContext * const a = avctx->priv_data;
 232     AVFrame *p= (AVFrame*)&a->picture;
 233
 234     mdec_common_init(avctx);
 235     init_vlcs();
 236     ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_zigzag_direct);
 237 /*
 238     for(i=0; i<64; i++){
 239         int index= ff_zigzag_direct[i];
 240         a->intra_matrix[i]= 64*ff_mpeg1_default_intra_matrix[index] / a->inv_qscale;
 241     }
 242 */
 243     p->qstride= a->mb_width;
 244     p->qscale_table= av_mallocz( p->qstride * a->mb_height);
 245     avctx->pix_fmt= PIX_FMT_YUV420P;
 246
 247     return 0;
 248 }
 249
 250 static av_cold int decode_end(AVCodecContext *avctx){
 251     MDECContext * const a = avctx->priv_data;
 252
 253     av_freep(&a->bitstream_buffer);
 254     av_freep(&a->picture.qscale_table);
 255     a->bitstream_buffer_size=0;
 256
 257     return 0;
 258 }
 259
 260 AVCodec mdec_decoder = {
 261     "mdec",
 262     CODEC_TYPE_VIDEO,
 263     CODEC_ID_MDEC,
 264     sizeof(MDECContext),
 265     decode_init,
 266     NULL,
 267     decode_end,
 268     decode_frame,
 269     CODEC_CAP_DR1,
 270 };
 271