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 libavcodec/dxa.c
  24  * DXA Video decoder
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "libavutil/intreadwrite.h"
  31 #include "avcodec.h"
  32
  33 #include <zlib.h>
  34
  35 /*
  36  * Decoder context
  37  */
  38 typedef struct DxaDecContext {
  39     AVCodecContext *avctx;
  40     AVFrame pic, prev;
  41
  42     int dsize;
  43     uint8_t *decomp_buf;
  44     uint32_t pal[256];
  45 } DxaDecContext;
  46
  47 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
  48 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
  49
  50 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
  51 {
  52     uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
  53     int i, j, k;
  54     int type, x, y, d, d2;
  55     int stride = c->pic.linesize[0];
  56     uint32_t mask;
  57
  58     code = src  + 12;
  59     data = code + ((avctx->width * avctx->height) >> 4);
  60     mv   = data + AV_RB32(src + 0);
  61     msk  = mv   + AV_RB32(src + 4);
  62
  63     for(j = 0; j < avctx->height; j += 4){
  64         for(i = 0; i < avctx->width; i += 4){
  65             tmp  = dst + i;
  66             tmp2 = ref + i;
  67             type = *code++;
  68             switch(type){
  69             case 4: // motion compensation
  70                 x = (*mv) >> 4;    if(x & 8) x = 8 - x;
  71                 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
  72                 tmp2 += x + y*stride;
  73             case 0: // skip
  74             case 5: // skip in method 12
  75                 for(y = 0; y < 4; y++){
  76                     memcpy(tmp, tmp2, 4);
  77                     tmp  += stride;
  78                     tmp2 += stride;
  79                 }
  80                 break;
  81             case 1:  // masked change
  82             case 10: // masked change with only half of pixels changed
  83             case 11: // cases 10-15 are for method 12 only
  84             case 12:
  85             case 13:
  86             case 14:
  87             case 15:
  88                 if(type == 1){
  89                     mask = AV_RB16(msk);
  90                     msk += 2;
  91                 }else{
  92                     type -= 10;
  93                     mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
  94                     msk++;
  95                 }
  96                 for(y = 0; y < 4; y++){
  97                     for(x = 0; x < 4; x++){
  98                         tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
  99                         mask <<= 1;
 100                     }
 101                     tmp  += stride;
 102                     tmp2 += stride;
 103                 }
 104                 break;
 105             case 2: // fill block
 106                 for(y = 0; y < 4; y++){
 107                     memset(tmp, data[0], 4);
 108                     tmp += stride;
 109                 }
 110                 data++;
 111                 break;
 112             case 3: // raw block
 113                 for(y = 0; y < 4; y++){
 114                     memcpy(tmp, data, 4);
 115                     data += 4;
 116                     tmp  += stride;
 117                 }
 118                 break;
 119             case 8: // subblocks - method 13 only
 120                 mask = *msk++;
 121                 for(k = 0; k < 4; k++){
 122                     d  = ((k & 1) << 1) + ((k & 2) * stride);
 123                     d2 = ((k & 1) << 1) + ((k & 2) * stride);
 124                     tmp2 = ref + i + d2;
 125                     switch(mask & 0xC0){
 126                     case 0x80: // motion compensation
 127                         x = (*mv) >> 4;    if(x & 8) x = 8 - x;
 128                         y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
 129                         tmp2 += x + y*stride;
 130                     case 0x00: // skip
 131                         tmp[d + 0         ] = tmp2[0];
 132                         tmp[d + 1         ] = tmp2[1];
 133                         tmp[d + 0 + stride] = tmp2[0 + stride];
 134                         tmp[d + 1 + stride] = tmp2[1 + stride];
 135                         break;
 136                     case 0x40: // fill
 137                         tmp[d + 0         ] = data[0];
 138                         tmp[d + 1         ] = data[0];
 139                         tmp[d + 0 + stride] = data[0];
 140                         tmp[d + 1 + stride] = data[0];
 141                         data++;
 142                         break;
 143                     case 0xC0: // raw
 144                         tmp[d + 0         ] = *data++;
 145                         tmp[d + 1         ] = *data++;
 146                         tmp[d + 0 + stride] = *data++;
 147                         tmp[d + 1 + stride] = *data++;
 148                         break;
 149                     }
 150                     mask <<= 2;
 151                 }
 152                 break;
 153             case 32: // vector quantization - 2 colors
 154                 mask = AV_RB16(msk);
 155                 msk += 2;
 156                 for(y = 0; y < 4; y++){
 157                     for(x = 0; x < 4; x++){
 158                         tmp[x] = data[mask & 1];
 159                         mask >>= 1;
 160                     }
 161                     tmp  += stride;
 162                     tmp2 += stride;
 163                 }
 164                 data += 2;
 165                 break;
 166             case 33: // vector quantization - 3 or 4 colors
 167             case 34:
 168                 mask = AV_RB32(msk);
 169                 msk += 4;
 170                 for(y = 0; y < 4; y++){
 171                     for(x = 0; x < 4; x++){
 172                         tmp[x] = data[mask & 3];
 173                         mask >>= 2;
 174                     }
 175                     tmp  += stride;
 176                     tmp2 += stride;
 177                 }
 178                 data += type - 30;
 179                 break;
 180             default:
 181                 av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
 182                 return -1;
 183             }
 184         }
 185         dst += stride * 4;
 186         ref += stride * 4;
 187     }
 188     return 0;
 189 }
 190
 191 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
 192 {
 193     const uint8_t *buf = avpkt->data;
 194     int buf_size = avpkt->size;
 195     DxaDecContext * const c = avctx->priv_data;
 196     uint8_t *outptr, *srcptr, *tmpptr;
 197     unsigned long dsize;
 198     int i, j, compr;
 199     int stride;
 200     int orig_buf_size = buf_size;
 201     int pc = 0;
 202
 203     /* make the palette available on the way out */
 204     if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
 205         int r, g, b;
 206
 207         buf += 4;
 208         for(i = 0; i < 256; i++){
 209             r = *buf++;
 210             g = *buf++;
 211             b = *buf++;
 212             c->pal[i] = (r << 16) | (g << 8) | b;
 213         }
 214         pc = 1;
 215         buf_size -= 768+4;
 216     }
 217
 218     if(avctx->get_buffer(avctx, &c->pic) < 0){
 219         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 220         return -1;
 221     }
 222     memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
 223     c->pic.palette_has_changed = pc;
 224
 225     outptr = c->pic.data[0];
 226     srcptr = c->decomp_buf;
 227     tmpptr = c->prev.data[0];
 228     stride = c->pic.linesize[0];
 229
 230     if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
 231         compr = -1;
 232     else
 233         compr = buf[4];
 234
 235     dsize = c->dsize;
 236     if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
 237         av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
 238         return -1;
 239     }
 240     switch(compr){
 241     case -1:
 242         c->pic.key_frame = 0;
 243         c->pic.pict_type = FF_P_TYPE;
 244         if(c->prev.data[0])
 245             memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
 246         else{ // Should happen only when first frame is 'NULL'
 247             memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
 248             c->pic.key_frame = 1;
 249             c->pic.pict_type = FF_I_TYPE;
 250         }
 251         break;
 252     case 2:
 253     case 3:
 254     case 4:
 255     case 5:
 256         c->pic.key_frame = !(compr & 1);
 257         c->pic.pict_type = (compr & 1) ? FF_P_TYPE : FF_I_TYPE;
 258         for(j = 0; j < avctx->height; j++){
 259             if(compr & 1){
 260                 for(i = 0; i < avctx->width; i++)
 261                     outptr[i] = srcptr[i] ^ tmpptr[i];
 262                 tmpptr += stride;
 263             }else
 264                 memcpy(outptr, srcptr, avctx->width);
 265             outptr += stride;
 266             srcptr += avctx->width;
 267         }
 268         break;
 269     case 12: // ScummVM coding
 270     case 13:
 271         c->pic.key_frame = 0;
 272         c->pic.pict_type = FF_P_TYPE;
 273         decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
 274         break;
 275     default:
 276         av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
 277         return -1;
 278     }
 279
 280     FFSWAP(AVFrame, c->pic, c->prev);
 281     if(c->pic.data[0])
 282         avctx->release_buffer(avctx, &c->pic);
 283
 284     *data_size = sizeof(AVFrame);
 285     *(AVFrame*)data = c->prev;
 286
 287     /* always report that the buffer was completely consumed */
 288     return orig_buf_size;
 289 }
 290
 291 static av_cold int decode_init(AVCodecContext *avctx)
 292 {
 293     DxaDecContext * const c = avctx->priv_data;
 294
 295     c->avctx = avctx;
 296     avctx->pix_fmt = PIX_FMT_PAL8;
 297
 298     c->dsize = avctx->width * avctx->height * 2;
 299     if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
 300         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 301         return -1;
 302     }
 303
 304     return 0;
 305 }
 306
 307 static av_cold int decode_end(AVCodecContext *avctx)
 308 {
 309     DxaDecContext * const c = avctx->priv_data;
 310
 311     av_freep(&c->decomp_buf);
 312     if(c->prev.data[0])
 313         avctx->release_buffer(avctx, &c->prev);
 314     if(c->pic.data[0])
 315         avctx->release_buffer(avctx, &c->pic);
 316
 317     return 0;
 318 }
 319
 320 AVCodec dxa_decoder = {
 321     "dxa",
 322     CODEC_TYPE_VIDEO,
 323     CODEC_ID_DXA,
 324     sizeof(DxaDecContext),
 325     decode_init,
 326     NULL,
 327     decode_end,
 328     decode_frame,
 329     CODEC_CAP_DR1,
 330     .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
 331 };
 332