libavcodec/dxa.c

   1 /*
   2  * Feeble Files/ScummVM DXA 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 dxa.c
  24  * DXA Video decoder
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "avcodec.h"
  31
  32 #include <zlib.h>
  33
  34 /*
  35  * Decoder context
  36  */
  37 typedef struct DxaDecContext {
  38     AVCodecContext *avctx;
  39     AVFrame pic, prev;
  40
  41     int dsize;
  42     uint8_t *decomp_buf;
  43     uint32_t pal[256];
  44 } DxaDecContext;
  45
  46 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
  47 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
  48
  49 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
  50 {
  51     uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
  52     int i, j, k;
  53     int type, x, y, d, d2;
  54     int stride = c->pic.linesize[0];
  55     uint32_t mask;
  56
  57     code = src  + 12;
  58     data = code + ((avctx->width * avctx->height) >> 4);
  59     mv   = data + AV_RB32(src + 0);
  60     msk  = mv   + AV_RB32(src + 4);
  61
  62     for(j = 0; j < avctx->height; j += 4){
  63         for(i = 0; i < avctx->width; i += 4){
  64             tmp  = dst + i;
  65             tmp2 = ref + i;
  66             type = *code++;
  67             switch(type){
  68             case 4: // motion compensation
  69                 x = (*mv) >> 4;    if(x & 8) x = 8 - x;
  70                 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
  71                 tmp2 += x + y*stride;
  72             case 0: // skip
  73             case 5: // skip in method 12
  74                 for(y = 0; y < 4; y++){
  75                     memcpy(tmp, tmp2, 4);
  76                     tmp  += stride;
  77                     tmp2 += stride;
  78                 }
  79                 break;
  80             case 1:  // masked change
  81             case 10: // masked change with only half of pixels changed
  82             case 11: // cases 10-15 are for method 12 only
  83             case 12:
  84             case 13:
  85             case 14:
  86             case 15:
  87                 if(type == 1){
  88                     mask = AV_RB16(msk);
  89                     msk += 2;
  90                 }else{
  91                     type -= 10;
  92                     mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
  93                     msk++;
  94                 }
  95                 for(y = 0; y < 4; y++){
  96                     for(x = 0; x < 4; x++){
  97                         tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
  98                         mask <<= 1;
  99                     }
 100                     tmp  += stride;
 101                     tmp2 += stride;
 102                 }
 103                 break;
 104             case 2: // fill block
 105                 for(y = 0; y < 4; y++){
 106                     memset(tmp, data[0], 4);
 107                     tmp += stride;
 108                 }
 109                 data++;
 110                 break;
 111             case 3: // raw block
 112                 for(y = 0; y < 4; y++){
 113                     memcpy(tmp, data, 4);
 114                     data += 4;
 115                     tmp  += stride;
 116                 }
 117                 break;
 118             case 8: // subblocks - method 13 only
 119                 mask = *msk++;
 120                 for(k = 0; k < 4; k++){
 121                     d  = ((k & 1) << 1) + ((k & 2) * stride);
 122                     d2 = ((k & 1) << 1) + ((k & 2) * stride);
 123                     tmp2 = ref + i + d2;
 124                     switch(mask & 0xC0){
 125                     case 0x80: // motion compensation
 126                         x = (*mv) >> 4;    if(x & 8) x = 8 - x;
 127                         y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
 128                         tmp2 += x + y*stride;
 129                     case 0x00: // skip
 130                         tmp[d + 0         ] = tmp2[0];
 131                         tmp[d + 1         ] = tmp2[1];
 132                         tmp[d + 0 + stride] = tmp2[0 + stride];
 133                         tmp[d + 1 + stride] = tmp2[1 + stride];
 134                         break;
 135                     case 0x40: // fill
 136                         tmp[d + 0         ] = data[0];
 137                         tmp[d + 1         ] = data[0];
 138                         tmp[d + 0 + stride] = data[0];
 139                         tmp[d + 1 + stride] = data[0];
 140                         data++;
 141                         break;
 142                     case 0xC0: // raw
 143                         tmp[d + 0         ] = *data++;
 144                         tmp[d + 1         ] = *data++;
 145                         tmp[d + 0 + stride] = *data++;
 146                         tmp[d + 1 + stride] = *data++;
 147                         break;
 148                     }
 149                     mask <<= 2;
 150                 }
 151                 break;
 152             case 32: // vector quantization - 2 colors
 153                 mask = AV_RB16(msk);
 154                 msk += 2;
 155                 for(y = 0; y < 4; y++){
 156                     for(x = 0; x < 4; x++){
 157                         tmp[x] = data[mask & 1];
 158                         mask >>= 1;
 159                     }
 160                     tmp  += stride;
 161                     tmp2 += stride;
 162                 }
 163                 data += 2;
 164                 break;
 165             case 33: // vector quantization - 3 or 4 colors
 166             case 34:
 167                 mask = AV_RB32(msk);
 168                 msk += 4;
 169                 for(y = 0; y < 4; y++){
 170                     for(x = 0; x < 4; x++){
 171                         tmp[x] = data[mask & 3];
 172                         mask >>= 2;
 173                     }
 174                     tmp  += stride;
 175                     tmp2 += stride;
 176                 }
 177                 data += type - 30;
 178                 break;
 179             default:
 180                 av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
 181                 return -1;
 182             }
 183         }
 184         dst += stride * 4;
 185         ref += stride * 4;
 186     }
 187     return 0;
 188 }
 189
 190 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
 191 {
 192     DxaDecContext * const c = avctx->priv_data;
 193     uint8_t *outptr, *srcptr, *tmpptr;
 194     unsigned long dsize;
 195     int i, j, compr;
 196     int stride;
 197     int orig_buf_size = buf_size;
 198     int pc = 0;
 199
 200     /* make the palette available on the way out */
 201     if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
 202         int r, g, b;
 203
 204         buf += 4;
 205         for(i = 0; i < 256; i++){
 206             r = *buf++;
 207             g = *buf++;
 208             b = *buf++;
 209             c->pal[i] = (r << 16) | (g << 8) | b;
 210         }
 211         pc = 1;
 212         buf_size -= 768+4;
 213     }
 214
 215     if(avctx->get_buffer(avctx, &c->pic) < 0){
 216         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 217         return -1;
 218     }
 219     memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
 220     c->pic.palette_has_changed = pc;
 221
 222     outptr = c->pic.data[0];
 223     srcptr = c->decomp_buf;
 224     tmpptr = c->prev.data[0];
 225     stride = c->pic.linesize[0];
 226
 227     if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
 228         compr = -1;
 229     else
 230         compr = buf[4];
 231
 232     dsize = c->dsize;
 233     if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
 234         av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
 235         return -1;
 236     }
 237     switch(compr){
 238     case -1:
 239         c->pic.key_frame = 0;
 240         c->pic.pict_type = FF_P_TYPE;
 241         if(c->prev.data[0])
 242             memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
 243         else{ // Should happen only when first frame is 'NULL'
 244             memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
 245             c->pic.key_frame = 1;
 246             c->pic.pict_type = FF_I_TYPE;
 247         }
 248         break;
 249     case 2:
 250     case 3:
 251     case 4:
 252     case 5:
 253         c->pic.key_frame = !(compr & 1);
 254         c->pic.pict_type = (compr & 1) ? FF_P_TYPE : FF_I_TYPE;
 255         for(j = 0; j < avctx->height; j++){
 256             if(compr & 1){
 257                 for(i = 0; i < avctx->width; i++)
 258                     outptr[i] = srcptr[i] ^ tmpptr[i];
 259                 tmpptr += stride;
 260             }else
 261                 memcpy(outptr, srcptr, avctx->width);
 262             outptr += stride;
 263             srcptr += avctx->width;
 264         }
 265         break;
 266     case 12: // ScummVM coding
 267     case 13:
 268         c->pic.key_frame = 0;
 269         c->pic.pict_type = FF_P_TYPE;
 270         decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
 271         break;
 272     default:
 273         av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
 274         return -1;
 275     }
 276
 277     FFSWAP(AVFrame, c->pic, c->prev);
 278     if(c->pic.data[0])
 279         avctx->release_buffer(avctx, &c->pic);
 280
 281     *data_size = sizeof(AVFrame);
 282     *(AVFrame*)data = c->prev;
 283
 284     /* always report that the buffer was completely consumed */
 285     return orig_buf_size;
 286 }
 287
 288 static av_cold int decode_init(AVCodecContext *avctx)
 289 {
 290     DxaDecContext * const c = avctx->priv_data;
 291
 292     c->avctx = avctx;
 293     avctx->pix_fmt = PIX_FMT_PAL8;
 294
 295     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
 296         return -1;
 297     }
 298
 299     c->dsize = avctx->width * avctx->height * 2;
 300     if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
 301         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 302         return -1;
 303     }
 304
 305     return 0;
 306 }
 307
 308 static av_cold int decode_end(AVCodecContext *avctx)
 309 {
 310     DxaDecContext * const c = avctx->priv_data;
 311
 312     av_freep(&c->decomp_buf);
 313     if(c->prev.data[0])
 314         avctx->release_buffer(avctx, &c->prev);
 315     if(c->pic.data[0])
 316         avctx->release_buffer(avctx, &c->pic);
 317
 318     return 0;
 319 }
 320
 321 AVCodec dxa_decoder = {
 322     "dxa",
 323     CODEC_TYPE_VIDEO,
 324     CODEC_ID_DXA,
 325     sizeof(DxaDecContext),
 326     decode_init,
 327     NULL,
 328     decode_end,
 329     decode_frame,
 330     .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
 331 };
 332