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     AVCodecContext *avctx;
00040     AVFrame pic, prev;
00041 
00042     int dsize;
00043     uint8_t *decomp_buf;
00044     uint32_t pal[256];
00045 } DxaDecContext;
00046 
00047 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
00048 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
00049 
00050 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, uint8_t *src, uint8_t *ref)
00051 {
00052     uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
00053     int i, j, k;
00054     int type, x, y, d, d2;
00055     int stride = c->pic.linesize[0];
00056     uint32_t mask;
00057 
00058     code = src  + 12;
00059     data = code + ((avctx->width * avctx->height) >> 4);
00060     mv   = data + AV_RB32(src + 0);
00061     msk  = mv   + AV_RB32(src + 4);
00062 
00063     for(j = 0; j < avctx->height; j += 4){
00064         for(i = 0; i < avctx->width; i += 4){
00065             tmp  = dst + i;
00066             tmp2 = ref + i;
00067             type = *code++;
00068             switch(type){
00069             case 4: // motion compensation
00070                 x = (*mv) >> 4;    if(x & 8) x = 8 - x;
00071                 y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
00072                 tmp2 += x + y*stride;
00073             case 0: // skip
00074             case 5: // skip in method 12
00075                 for(y = 0; y < 4; y++){
00076                     memcpy(tmp, tmp2, 4);
00077                     tmp  += stride;
00078                     tmp2 += stride;
00079                 }
00080                 break;
00081             case 1:  // masked change
00082             case 10: // masked change with only half of pixels changed
00083             case 11: // cases 10-15 are for method 12 only
00084             case 12:
00085             case 13:
00086             case 14:
00087             case 15:
00088                 if(type == 1){
00089                     mask = AV_RB16(msk);
00090                     msk += 2;
00091                 }else{
00092                     type -= 10;
00093                     mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
00094                     msk++;
00095                 }
00096                 for(y = 0; y < 4; y++){
00097                     for(x = 0; x < 4; x++){
00098                         tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
00099                         mask <<= 1;
00100                     }
00101                     tmp  += stride;
00102                     tmp2 += stride;
00103                 }
00104                 break;
00105             case 2: // fill block
00106                 for(y = 0; y < 4; y++){
00107                     memset(tmp, data[0], 4);
00108                     tmp += stride;
00109                 }
00110                 data++;
00111                 break;
00112             case 3: // raw block
00113                 for(y = 0; y < 4; y++){
00114                     memcpy(tmp, data, 4);
00115                     data += 4;
00116                     tmp  += stride;
00117                 }
00118                 break;
00119             case 8: // subblocks - method 13 only
00120                 mask = *msk++;
00121                 for(k = 0; k < 4; k++){
00122                     d  = ((k & 1) << 1) + ((k & 2) * stride);
00123                     d2 = ((k & 1) << 1) + ((k & 2) * stride);
00124                     tmp2 = ref + i + d2;
00125                     switch(mask & 0xC0){
00126                     case 0x80: // motion compensation
00127                         x = (*mv) >> 4;    if(x & 8) x = 8 - x;
00128                         y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
00129                         tmp2 += x + y*stride;
00130                     case 0x00: // skip
00131                         tmp[d + 0         ] = tmp2[0];
00132                         tmp[d + 1         ] = tmp2[1];
00133                         tmp[d + 0 + stride] = tmp2[0 + stride];
00134                         tmp[d + 1 + stride] = tmp2[1 + stride];
00135                         break;
00136                     case 0x40: // fill
00137                         tmp[d + 0         ] = data[0];
00138                         tmp[d + 1         ] = data[0];
00139                         tmp[d + 0 + stride] = data[0];
00140                         tmp[d + 1 + stride] = data[0];
00141                         data++;
00142                         break;
00143                     case 0xC0: // raw
00144                         tmp[d + 0         ] = *data++;
00145                         tmp[d + 1         ] = *data++;
00146                         tmp[d + 0 + stride] = *data++;
00147                         tmp[d + 1 + stride] = *data++;
00148                         break;
00149                     }
00150                     mask <<= 2;
00151                 }
00152                 break;
00153             case 32: // vector quantization - 2 colors
00154                 mask = AV_RB16(msk);
00155                 msk += 2;
00156                 for(y = 0; y < 4; y++){
00157                     for(x = 0; x < 4; x++){
00158                         tmp[x] = data[mask & 1];
00159                         mask >>= 1;
00160                     }
00161                     tmp  += stride;
00162                     tmp2 += stride;
00163                 }
00164                 data += 2;
00165                 break;
00166             case 33: // vector quantization - 3 or 4 colors
00167             case 34:
00168                 mask = AV_RB32(msk);
00169                 msk += 4;
00170                 for(y = 0; y < 4; y++){
00171                     for(x = 0; x < 4; x++){
00172                         tmp[x] = data[mask & 3];
00173                         mask >>= 2;
00174                     }
00175                     tmp  += stride;
00176                     tmp2 += stride;
00177                 }
00178                 data += type - 30;
00179                 break;
00180             default:
00181                 av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
00182                 return -1;
00183             }
00184         }
00185         dst += stride * 4;
00186         ref += stride * 4;
00187     }
00188     return 0;
00189 }
00190 
00191 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
00192 {
00193     const uint8_t *buf = avpkt->data;
00194     int buf_size = avpkt->size;
00195     DxaDecContext * const c = avctx->priv_data;
00196     uint8_t *outptr, *srcptr, *tmpptr;
00197     unsigned long dsize;
00198     int i, j, compr;
00199     int stride;
00200     int orig_buf_size = buf_size;
00201     int pc = 0;
00202 
00203     /* make the palette available on the way out */
00204     if(buf[0]=='C' && buf[1]=='M' && buf[2]=='A' && buf[3]=='P'){
00205         int r, g, b;
00206 
00207         buf += 4;
00208         for(i = 0; i < 256; i++){
00209             r = *buf++;
00210             g = *buf++;
00211             b = *buf++;
00212             c->pal[i] = (r << 16) | (g << 8) | b;
00213         }
00214         pc = 1;
00215         buf_size -= 768+4;
00216     }
00217 
00218     if(avctx->get_buffer(avctx, &c->pic) < 0){
00219         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00220         return -1;
00221     }
00222     memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
00223     c->pic.palette_has_changed = pc;
00224 
00225     outptr = c->pic.data[0];
00226     srcptr = c->decomp_buf;
00227     tmpptr = c->prev.data[0];
00228     stride = c->pic.linesize[0];
00229 
00230     if(buf[0]=='N' && buf[1]=='U' && buf[2]=='L' && buf[3]=='L')
00231         compr = -1;
00232     else
00233         compr = buf[4];
00234 
00235     dsize = c->dsize;
00236     if((compr != 4 && compr != -1) && uncompress(c->decomp_buf, &dsize, buf + 9, buf_size - 9) != Z_OK){
00237         av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
00238         return -1;
00239     }
00240     switch(compr){
00241     case -1:
00242         c->pic.key_frame = 0;
00243         c->pic.pict_type = AV_PICTURE_TYPE_P;
00244         if(c->prev.data[0])
00245             memcpy(c->pic.data[0], c->prev.data[0], c->pic.linesize[0] * avctx->height);
00246         else{ // Should happen only when first frame is 'NULL'
00247             memset(c->pic.data[0], 0, c->pic.linesize[0] * avctx->height);
00248             c->pic.key_frame = 1;
00249             c->pic.pict_type = AV_PICTURE_TYPE_I;
00250         }
00251         break;
00252     case 2:
00253     case 3:
00254     case 4:
00255     case 5:
00256         c->pic.key_frame = !(compr & 1);
00257         c->pic.pict_type = (compr & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
00258         for(j = 0; j < avctx->height; j++){
00259             if(compr & 1){
00260                 for(i = 0; i < avctx->width; i++)
00261                     outptr[i] = srcptr[i] ^ tmpptr[i];
00262                 tmpptr += stride;
00263             }else
00264                 memcpy(outptr, srcptr, avctx->width);
00265             outptr += stride;
00266             srcptr += avctx->width;
00267         }
00268         break;
00269     case 12: // ScummVM coding
00270     case 13:
00271         c->pic.key_frame = 0;
00272         c->pic.pict_type = AV_PICTURE_TYPE_P;
00273         decode_13(avctx, c, c->pic.data[0], srcptr, c->prev.data[0]);
00274         break;
00275     default:
00276         av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", buf[4]);
00277         return -1;
00278     }
00279 
00280     FFSWAP(AVFrame, c->pic, c->prev);
00281     if(c->pic.data[0])
00282         avctx->release_buffer(avctx, &c->pic);
00283 
00284     *data_size = sizeof(AVFrame);
00285     *(AVFrame*)data = c->prev;
00286 
00287     /* always report that the buffer was completely consumed */
00288     return orig_buf_size;
00289 }
00290 
00291 static av_cold int decode_init(AVCodecContext *avctx)
00292 {
00293     DxaDecContext * const c = avctx->priv_data;
00294 
00295     c->avctx = avctx;
00296     avctx->pix_fmt = PIX_FMT_PAL8;
00297 
00298     avcodec_get_frame_defaults(&c->pic);
00299     avcodec_get_frame_defaults(&c->prev);
00300 
00301     c->dsize = avctx->width * avctx->height * 2;
00302     if((c->decomp_buf = av_malloc(c->dsize)) == NULL) {
00303         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
00304         return -1;
00305     }
00306 
00307     return 0;
00308 }
00309 
00310 static av_cold int decode_end(AVCodecContext *avctx)
00311 {
00312     DxaDecContext * const c = avctx->priv_data;
00313 
00314     av_freep(&c->decomp_buf);
00315     if(c->prev.data[0])
00316         avctx->release_buffer(avctx, &c->prev);
00317     if(c->pic.data[0])
00318         avctx->release_buffer(avctx, &c->pic);
00319 
00320     return 0;
00321 }
00322 
00323 AVCodec ff_dxa_decoder = {
00324     "dxa",
00325     AVMEDIA_TYPE_VIDEO,
00326     CODEC_ID_DXA,
00327     sizeof(DxaDecContext),
00328     decode_init,
00329     NULL,
00330     decode_end,
00331     decode_frame,
00332     CODEC_CAP_DR1,
00333     .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
00334 };
00335