libavcodec/dxa.c

   1 /*
   2  * Feeble Files/ScummVM DXA decoder
   3  * Copyright (c) 2007 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  24  * DXA Video decoder
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "libavutil/common.h"
  31 #include "libavutil/intreadwrite.h"
  32 #include "avcodec.h"
  33 #include "internal.h"
  34
  35 #include <zlib.h>
  36
  37 /*
  38  * Decoder context
  39  */
  40 typedef struct DxaDecContext {
  41     AVFrame *prev;
  42
  43     int dsize;
  44     uint8_t *decomp_buf;
  45     uint32_t pal[256];
  46 } DxaDecContext;
  47
  48 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
  49 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
  50
  51 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst,
  52                      int stride, uint8_t *src, uint8_t *ref)
  53 {
  54     uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
  55     int i, j, k;
  56     int type, x, y, d, d2;
  57     uint32_t mask;
  58
  59     code = src  + 12;
  60     data = code + ((avctx->width * avctx->height) >> 4);
  61     mv   = data + AV_RB32(src + 0);
  62     msk  = mv   + AV_RB32(src + 4);
  63
  64     for(j = 0; j < avctx->height; j += 4){
  65         for(i = 0; i < avctx->width; i += 4){
  66             tmp  = dst + i;
  67             tmp2 = ref + i;
  68             type = *code++;
  69             switch(type){
  70             case 4: // motion compensation
  71                 x = (*mv) >> 4;    if(x & 8) x = 8 - x;
  72                 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
  73                 tmp2 += x + y*stride;
  74             case 0: // skip
  75             case 5: // skip in method 12
  76                 for(y = 0; y < 4; y++){
  77                     memcpy(tmp, tmp2, 4);
  78                     tmp  += stride;
  79                     tmp2 += stride;
  80                 }
  81                 break;
  82             case 1:  // masked change
  83             case 10: // masked change with only half of pixels changed
  84             case 11: // cases 10-15 are for method 12 only
  85             case 12:
  86             case 13:
  87             case 14:
  88             case 15:
  89                 if(type == 1){
  90                     mask = AV_RB16(msk);
  91                     msk += 2;
  92                 }else{
  93                     type -= 10;
  94                     mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
  95                     msk++;
  96                 }
  97                 for(y = 0; y < 4; y++){
  98                     for(x = 0; x < 4; x++){
  99                         tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
 100                         mask <<= 1;
 101                     }
 102                     tmp  += stride;
 103                     tmp2 += stride;
 104                 }
 105                 break;
 106             case 2: // fill block
 107                 for(y = 0; y < 4; y++){
 108                     memset(tmp, data[0], 4);
 109                     tmp += stride;
 110                 }
 111                 data++;
 112                 break;
 113             case 3: // raw block
 114                 for(y = 0; y < 4; y++){
 115                     memcpy(tmp, data, 4);
 116                     data += 4;
 117                     tmp  += stride;
 118                 }
 119                 break;
 120             case 8: // subblocks - method 13 only
 121                 mask = *msk++;
 122                 for(k = 0; k < 4; k++){
 123                     d  = ((k & 1) << 1) + ((k & 2) * stride);
 124                     d2 = ((k & 1) << 1) + ((k & 2) * stride);
 125                     tmp2 = ref + i + d2;
 126                     switch(mask & 0xC0){
 127                     case 0x80: // motion compensation
 128                         x = (*mv) >> 4;    if(x & 8) x = 8 - x;
 129                         y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
 130                         tmp2 += x + y*stride;
 131                     case 0x00: // skip
 132                         tmp[d + 0         ] = tmp2[0];
 133                         tmp[d + 1         ] = tmp2[1];
 134                         tmp[d + 0 + stride] = tmp2[0 + stride];
 135                         tmp[d + 1 + stride] = tmp2[1 + stride];
 136                         break;
 137                     case 0x40: // fill
 138                         tmp[d + 0         ] = data[0];
 139                         tmp[d + 1         ] = data[0];
 140                         tmp[d + 0 + stride] = data[0];
 141                         tmp[d + 1 + stride] = data[0];
 142                         data++;
 143                         break;
 144                     case 0xC0: // raw
 145                         tmp[d + 0         ] = *data++;
 146                         tmp[d + 1         ] = *data++;
 147                         tmp[d + 0 + stride] = *data++;
 148                         tmp[d + 1 + stride] = *data++;
 149                         break;
 150                     }
 151                     mask <<= 2;
 152                 }
 153                 break;
 154             case 32: // vector quantization - 2 colors
 155                 mask = AV_RB16(msk);
 156                 msk += 2;
 157                 for(y = 0; y < 4; y++){
 158                     for(x = 0; x < 4; x++){
 159                         tmp[x] = data[mask & 1];
 160                         mask >>= 1;
 161                     }
 162                     tmp  += stride;
 163                     tmp2 += stride;
 164                 }
 165                 data += 2;
 166                 break;
 167             case 33: // vector quantization - 3 or 4 colors
 168             case 34:
 169                 mask = AV_RB32(msk);
 170                 msk += 4;
 171                 for(y = 0; y < 4; y++){
 172                     for(x = 0; x < 4; x++){
 173                         tmp[x] = data[mask & 3];
 174                         mask >>= 2;
 175                     }
 176                     tmp  += stride;
 177                     tmp2 += stride;
 178                 }
 179                 data += type - 30;
 180                 break;
 181             default:
 182                 av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
 183                 return AVERROR_INVALIDDATA;
 184             }
 185         }
 186         dst += stride * 4;
 187         ref += stride * 4;
 188     }
 189     return 0;
 190 }
 191
 192 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
 193 {
 194     AVFrame *frame = data;
 195     const uint8_t *buf = avpkt->data;
 196     int buf_size = avpkt->size;
 197     DxaDecContext * const c = avctx->priv_data;
 198     uint8_t *outptr, *srcptr, *tmpptr;
 199     unsigned long dsize;
 200     int i, j, compr, ret;
 201     int stride;
 202     int orig_buf_size = buf_size;
 203     int pc = 0;
 204
 205     /* make the palette available on the way out */
 206     if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
 207         int r, g, b;
 208
 209         buf += 4;
 210         for(i = 0; i < 256; i++){
 211             r = *buf++;
 212             g = *buf++;
 213             b = *buf++;
 214             c->pal[i] = (r << 16) | (g << 8) | b;
 215         }
 216         pc = 1;
 217         buf_size -= 768+4;
 218     }
 219
 220     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
 221         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 222         return ret;
 223     }
 224     memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
 225     frame->palette_has_changed = pc;
 226
 227     outptr = frame->data[0];
 228     srcptr = c->decomp_buf;
 229     tmpptr = c->prev->data[0];
 230     stride = frame->linesize[0];
 231
 232     if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
 233         compr = -1;
 234     else
 235         compr = buf[4];
 236
 237     dsize = c->dsize;
 238     if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
 239         av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
 240         return AVERROR_UNKNOWN;
 241     }
 242     switch(compr){
 243     case -1:
 244         frame->key_frame = 0;
 245         frame->pict_type = AV_PICTURE_TYPE_P;
 246         if (c->prev->data[0])
 247             memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height);
 248         else{ // Should happen only when first frame is 'NULL'
 249             memset(frame->data[0], 0, frame->linesize[0] * avctx->height);
 250             frame->key_frame = 1;
 251             frame->pict_type = AV_PICTURE_TYPE_I;
 252         }
 253         break;
 254     case 2:
 255     case 4:
 256         frame->key_frame = 1;
 257         frame->pict_type = AV_PICTURE_TYPE_I;
 258         for (j = 0; j < avctx->height; j++) {
 259                 memcpy(outptr, srcptr, avctx->width);
 260             outptr += stride;
 261             srcptr += avctx->width;
 262         }
 263         break;
 264     case 3:
 265     case 5:
 266         if (!tmpptr) {
 267             av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
 268             return AVERROR_INVALIDDATA;
 269         }
 270         frame->key_frame = 0;
 271         frame->pict_type = AV_PICTURE_TYPE_P;
 272         for (j = 0; j < avctx->height; j++) {
 273             for (i = 0; i < avctx->width; i++)
 274                 outptr[i] = srcptr[i] ^ tmpptr[i];
 275             tmpptr += stride;
 276             outptr += stride;
 277             srcptr += avctx->width;
 278         }
 279         break;
 280     case 12: // ScummVM coding
 281     case 13:
 282         frame->key_frame = 0;
 283         frame->pict_type = AV_PICTURE_TYPE_P;
 284         decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, c->prev->data[0]);
 285         break;
 286     default:
 287         av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
 288         return AVERROR_INVALIDDATA;
 289     }
 290
 291     av_frame_unref(c->prev);
 292     if ((ret = av_frame_ref(c->prev, frame)) < 0)
 293         return ret;
 294
 295     *got_frame = 1;
 296
 297     /* always report that the buffer was completely consumed */
 298     return orig_buf_size;
 299 }
 300
 301 static av_cold int decode_init(AVCodecContext *avctx)
 302 {
 303     DxaDecContext * const c = avctx->priv_data;
 304
 305     c->prev = av_frame_alloc();
 306     if (!c->prev)
 307         return AVERROR(ENOMEM);
 308
 309     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 310
 311     c->dsize = avctx->width * avctx->height * 2;
 312     if (!(c->decomp_buf = av_malloc(c->dsize))) {
 313         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 314         return AVERROR(ENOMEM);
 315     }
 316
 317     return 0;
 318 }
 319
 320 static av_cold int decode_end(AVCodecContext *avctx)
 321 {
 322     DxaDecContext * const c = avctx->priv_data;
 323
 324     av_freep(&c->decomp_buf);
 325     av_frame_free(&c->prev);
 326
 327     return 0;
 328 }
 329
 330 AVCodec ff_dxa_decoder = {
 331     .name           = "dxa",
 332     .long_name      = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
 333     .type           = AVMEDIA_TYPE_VIDEO,
 334     .id             = AV_CODEC_ID_DXA,
 335     .priv_data_size = sizeof(DxaDecContext),
 336     .init           = decode_init,
 337     .close          = decode_end,
 338     .decode         = decode_frame,
 339     .capabilities   = AV_CODEC_CAP_DR1,
 340 };