FFmpeg: libavcodec/dxa.c Source File

00001 /*
00002  * Feeble Files/ScummVM DXA decoder
00003  * Copyright (c) 2007 Konstantin Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include <stdio.h>
00028 #include <stdlib.h>
00029 
00030 #include "libavutil/intreadwrite.h"
00031 #include "avcodec.h"
00032 
00033 #include <zlib.h>
00034 
00035 /*
00036  * Decoder context
00037  */
00038 typedef struct DxaDecContext {
00039     AVFrame pic, prev;
00040 
00041     int dsize;
00042     uint8_t *decomp_buf;
00043     uint32_t pal[256];
00044 } DxaDecContext;
00045 
00046 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
00047 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
00048 
00049 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
00050 {
00051     uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
00052     int i, j, k;
00053     int type, x, y, d, d2;
00054     int stride = c->pic.linesize[0];
00055     uint32_t mask;
00056 
00057     code = src  + 12;
00058     data = code + ((avctx->width * avctx->height) >> 4);
00059     mv   = data + AV_RB32(src + 0);
00060     msk  = mv   + AV_RB32(src + 4);
00061 
00062     for(j = 0; j < avctx->height; j += 4){
00063         for(i = 0; i < avctx->width; i += 4){
00064             tmp  = dst + i;
00065             tmp2 = ref + i;
00066             type = *code++;
00067             switch(type){
00068             case 4: // motion compensation
00069                 x = (*mv) >> 4;    if(x & 8) x = 8 - x;
00070                 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
00071                 tmp2 += x + y*stride;
00072             case 0: // skip
00073             case 5: // skip in method 12
00074                 for(y = 0; y < 4; y++){
00075                     memcpy(tmp, tmp2, 4);
00076                     tmp  += stride;
00077                     tmp2 += stride;
00078                 }
00079                 break;
00080             case 1:  // masked change
00081             case 10: // masked change with only half of pixels changed
00082             case 11: // cases 10-15 are for method 12 only
00083             case 12:
00084             case 13:
00085             case 14:
00086             case 15:
00087                 if(type == 1){
00088                     mask = AV_RB16(msk);
00089                     msk += 2;
00090                 }else{
00091                     type -= 10;
00092                     mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
00093                     msk++;
00094                 }
00095                 for(y = 0; y < 4; y++){
00096                     for(x = 0; x < 4; x++){
00097                         tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
00098                         mask <<= 1;
00099                     }
00100                     tmp  += stride;
00101                     tmp2 += stride;
00102                 }
00103                 break;
00104             case 2: // fill block
00105                 for(y = 0; y < 4; y++){
00106                     memset(tmp, data[0], 4);
00107                     tmp += stride;
00108                 }
00109                 data++;
00110                 break;
00111             case 3: // raw block
00112                 for(y = 0; y < 4; y++){
00113                     memcpy(tmp, data, 4);
00114                     data += 4;
00115                     tmp  += stride;
00116                 }
00117                 break;
00118             case 8: // subblocks - method 13 only
00119                 mask = *msk++;
00120                 for(k = 0; k < 4; k++){
00121                     d  = ((k & 1) << 1) + ((k & 2) * stride);
00122                     d2 = ((k & 1) << 1) + ((k & 2) * stride);
00123                     tmp2 = ref + i + d2;
00124                     switch(mask & 0xC0){
00125                     case 0x80: // motion compensation
00126                         x = (*mv) >> 4;    if(x & 8) x = 8 - x;
00127                         y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
00128                         tmp2 += x + y*stride;
00129                     case 0x00: // skip
00130                         tmp[d + 0         ] = tmp2[0];
00131                         tmp[d + 1         ] = tmp2[1];
00132                         tmp[d + 0 + stride] = tmp2[0 + stride];
00133                         tmp[d + 1 + stride] = tmp2[1 + stride];
00134                         break;
00135                     case 0x40: // fill
00136                         tmp[d + 0         ] = data[0];
00137                         tmp[d + 1         ] = data[0];
00138                         tmp[d + 0 + stride] = data[0];
00139                         tmp[d + 1 + stride] = data[0];
00140                         data++;
00141                         break;
00142                     case 0xC0: // raw
00143                         tmp[d + 0         ] = *data++;
00144                         tmp[d + 1         ] = *data++;
00145                         tmp[d + 0 + stride] = *data++;
00146                         tmp[d + 1 + stride] = *data++;
00147                         break;
00148                     }
00149                     mask <<= 2;
00150                 }
00151                 break;
00152             case 32: // vector quantization - 2 colors
00153                 mask = AV_RB16(msk);
00154                 msk += 2;
00155                 for(y = 0; y < 4; y++){
00156                     for(x = 0; x < 4; x++){
00157                         tmp[x] = data[mask & 1];
00158                         mask >>= 1;
00159                     }
00160                     tmp  += stride;
00161                     tmp2 += stride;
00162                 }
00163                 data += 2;
00164                 break;
00165             case 33: // vector quantization - 3 or 4 colors
00166             case 34:
00167                 mask = AV_RB32(msk);
00168                 msk += 4;
00169                 for(y = 0; y < 4; y++){
00170                     for(x = 0; x < 4; x++){
00171                         tmp[x] = data[mask & 3];
00172                         mask >>= 2;
00173                     }
00174                     tmp  += stride;
00175                     tmp2 += stride;
00176                 }
00177                 data += type - 30;
00178                 break;
00179             default:
00180                 av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
00181                 return -1;
00182             }
00183         }
00184         dst += stride * 4;
00185         ref += stride * 4;
00186     }
00187     return 0;
00188 }
00189 
00190 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
00191 {
00192     const uint8_t *buf = avpkt->data;
00193     int buf_size = avpkt->size;
00194     DxaDecContext * const c = avctx->priv_data;
00195     uint8_t *outptr, *srcptr, *tmpptr;
00196     unsigned long dsize;
00197     int i, j, compr;
00198     int stride;
00199     int orig_buf_size = buf_size;
00200     int pc = 0;
00201 
00202     /* make the palette available on the way out */
00203     if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
00204         int r, g, b;
00205 
00206         buf += 4;
00207         for(i = 0; i < 256; i++){
00208             r = *buf++;
00209             g = *buf++;
00210             b = *buf++;
00211             c->pal[i] = 0xFF << 24 | r << 16 | g << 8 | b;
00212         }
00213         pc = 1;
00214         buf_size -= 768+4;
00215     }
00216 
00217     if(avctx->get_buffer(avctx, &c->pic) < 0){
00218         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00219         return -1;
00220     }
00221     memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
00222     c->pic.palette_has_changed = pc;
00223 
00224     outptr = c->pic.data[0];
00225     srcptr = c->decomp_buf;
00226     tmpptr = c->prev.data[0];
00227     stride = c->pic.linesize[0];
00228 
00229     if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
00230         compr = -1;
00231     else
00232         compr = buf[4];
00233 
00234     dsize = c->dsize;
00235     if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
00236         av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
00237         return -1;
00238     }
00239     switch(compr){
00240     case -1:
00241         c->pic.key_frame = 0;
00242         c->pic.pict_type = AV_PICTURE_TYPE_P;
00243         if(c->prev.data[0])
00244             memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
00245         else{ // Should happen only when first frame is 'NULL'
00246             memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
00247             c->pic.key_frame = 1;
00248             c->pic.pict_type = AV_PICTURE_TYPE_I;
00249         }
00250         break;
00251     case 2:
00252     case 3:
00253     case 4:
00254     case 5:
00255         c->pic.key_frame = !(compr & 1);
00256         c->pic.pict_type = (compr & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
00257         for(j = 0; j < avctx->height; j++){
00258             if(compr & 1){
00259                 for(i = 0; i < avctx->width; i++)
00260                     outptr[i] = srcptr[i] ^ tmpptr[i];
00261                 tmpptr += stride;
00262             }else
00263                 memcpy(outptr, srcptr, avctx->width);
00264             outptr += stride;
00265             srcptr += avctx->width;
00266         }
00267         break;
00268     case 12: // ScummVM coding
00269     case 13:
00270         c->pic.key_frame = 0;
00271         c->pic.pict_type = AV_PICTURE_TYPE_P;
00272         decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
00273         break;
00274     default:
00275         av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
00276         return -1;
00277     }
00278 
00279     FFSWAP(AVFrame, c->pic, c->prev);
00280     if(c->pic.data[0])
00281         avctx->release_buffer(avctx, &c->pic);
00282 
00283     *data_size = sizeof(AVFrame);
00284     *(AVFrame*)data = c->prev;
00285 
00286     /* always report that the buffer was completely consumed */
00287     return orig_buf_size;
00288 }
00289 
00290 static av_cold int decode_init(AVCodecContext *avctx)
00291 {
00292     DxaDecContext * const c = avctx->priv_data;
00293 
00294     avctx->pix_fmt = PIX_FMT_PAL8;
00295 
00296     avcodec_get_frame_defaults(&c->pic);
00297     avcodec_get_frame_defaults(&c->prev);
00298 
00299     c->dsize = avctx->width * avctx->height * 2;
00300     if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
00301         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
00302         return -1;
00303     }
00304 
00305     return 0;
00306 }
00307 
00308 static av_cold int decode_end(AVCodecContext *avctx)
00309 {
00310     DxaDecContext * const c = avctx->priv_data;
00311 
00312     av_freep(&c->decomp_buf);
00313     if(c->prev.data[0])
00314         avctx->release_buffer(avctx, &c->prev);
00315     if(c->pic.data[0])
00316         avctx->release_buffer(avctx, &c->pic);
00317 
00318     return 0;
00319 }
00320 
00321 AVCodec ff_dxa_decoder = {
00322     .name           = "dxa",
00323     .type           = AVMEDIA_TYPE_VIDEO,
00324     .id             = CODEC_ID_DXA,
00325     .priv_data_size = sizeof(DxaDecContext),
00326     .init           = decode_init,
00327     .close          = decode_end,
00328     .decode         = decode_frame,
00329     .capabilities   = CODEC_CAP_DR1,
00330     .long_name      = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
00331 };