libavcodec/tscc.c

   1 /*
   2  * TechSmith Camtasia decoder
   3  * Copyright (c) 2004 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 tscc.c
  24  * TechSmith Camtasia decoder
  25  *
  26  * Fourcc: TSCC
  27  *
  28  * Codec is very simple:
  29  *  it codes picture (picture difference, really)
  30  *  with algorithm almost identical to Windows RLE8,
  31  *  only without padding and with greater pixel sizes,
  32  *  then this coded picture is packed with ZLib
  33  *
  34  * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
  35  *
  36  */
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40
  41 #include "avcodec.h"
  42
  43 #ifdef CONFIG_ZLIB
  44 #include <zlib.h>
  45 #endif
  46
  47
  48 /*
  49  * Decoder context
  50  */
  51 typedef struct TsccContext {
  52
  53     AVCodecContext *avctx;
  54     AVFrame pic;
  55
  56     // Bits per pixel
  57     int bpp;
  58     // Decompressed data size
  59     unsigned int decomp_size;
  60     // Decompression buffer
  61     unsigned char* decomp_buf;
  62     int height;
  63 #ifdef CONFIG_ZLIB
  64     z_stream zstream;
  65 #endif
  66 } CamtasiaContext;
  67
  68 /*
  69  *
  70  * Decode RLE - almost identical to Windows BMP RLE8
  71  *              and enhanced to bigger color depths
  72  *
  73  */
  74
  75 static int decode_rle(CamtasiaContext *c, unsigned int srcsize)
  76 {
  77     unsigned char *src = c->decomp_buf;
  78     unsigned char *output, *output_end;
  79     int p1, p2, line=c->height, pos=0, i;
  80     uint16_t pix16;
  81     uint32_t pix32;
  82
  83     output = c->pic.data[0] + (c->height - 1) * c->pic.linesize[0];
  84     output_end = c->pic.data[0] + (c->height) * c->pic.linesize[0];
  85     while(src < c->decomp_buf + srcsize) {
  86         p1 = *src++;
  87         if(p1 == 0) { //Escape code
  88             p2 = *src++;
  89             if(p2 == 0) { //End-of-line
  90                 output = c->pic.data[0] + (--line) * c->pic.linesize[0];
  91                 if (line < 0)
  92                     return -1;
  93                 pos = 0;
  94                 continue;
  95             } else if(p2 == 1) { //End-of-picture
  96                 return 0;
  97             } else if(p2 == 2) { //Skip
  98                 p1 = *src++;
  99                 p2 = *src++;
 100                 line -= p2;
 101                 if (line < 0)
 102                     return -1;
 103                 pos += p1;
 104                 output = c->pic.data[0] + line * c->pic.linesize[0] + pos * (c->bpp / 8);
 105                 continue;
 106             }
 107             // Copy data
 108             if (output + p2 * (c->bpp / 8) > output_end) {
 109                 src += p2 * (c->bpp / 8);
 110                 continue;
 111             }
 112             if ((c->bpp == 8) || (c->bpp == 24)) {
 113                 for(i = 0; i < p2 * (c->bpp / 8); i++) {
 114                     *output++ = *src++;
 115                 }
 116                 // RLE8 copy is actually padded - and runs are not!
 117                 if(c->bpp == 8 && (p2 & 1)) {
 118                     src++;
 119                 }
 120             } else if (c->bpp == 16) {
 121                 for(i = 0; i < p2; i++) {
 122                     pix16 = AV_RL16(src);
 123                     src += 2;
 124                     *(uint16_t*)output = pix16;
 125                     output += 2;
 126                 }
 127             } else if (c->bpp == 32) {
 128                 for(i = 0; i < p2; i++) {
 129                     pix32 = AV_RL32(src);
 130                     src += 4;
 131                     *(uint32_t*)output = pix32;
 132                     output += 4;
 133                 }
 134             }
 135             pos += p2;
 136         } else { //Run of pixels
 137             int pix[4]; //original pixel
 138             switch(c->bpp){
 139             case  8: pix[0] = *src++;
 140                      break;
 141             case 16: pix16 = AV_RL16(src);
 142                      src += 2;
 143                      *(uint16_t*)pix = pix16;
 144                      break;
 145             case 24: pix[0] = *src++;
 146                      pix[1] = *src++;
 147                      pix[2] = *src++;
 148                      break;
 149             case 32: pix32 = AV_RL32(src);
 150                      src += 4;
 151                      *(uint32_t*)pix = pix32;
 152                      break;
 153             }
 154             if (output + p1 * (c->bpp / 8) > output_end)
 155                 continue;
 156             for(i = 0; i < p1; i++) {
 157                 switch(c->bpp){
 158                 case  8: *output++ = pix[0];
 159                          break;
 160                 case 16: *(uint16_t*)output = pix16;
 161                          output += 2;
 162                          break;
 163                 case 24: *output++ = pix[0];
 164                          *output++ = pix[1];
 165                          *output++ = pix[2];
 166                          break;
 167                 case 32: *(uint32_t*)output = pix32;
 168                          output += 4;
 169                          break;
 170                 }
 171             }
 172             pos += p1;
 173         }
 174     }
 175
 176     av_log(c->avctx, AV_LOG_ERROR, "Camtasia warning: no End-of-picture code\n");
 177     return 1;
 178 }
 179
 180 /*
 181  *
 182  * Decode a frame
 183  *
 184  */
 185 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
 186 {
 187     CamtasiaContext * const c = avctx->priv_data;
 188     const unsigned char *encoded = buf;
 189     unsigned char *outptr;
 190 #ifdef CONFIG_ZLIB
 191     int zret; // Zlib return code
 192 #endif
 193     int len = buf_size;
 194
 195     if(c->pic.data[0])
 196             avctx->release_buffer(avctx, &c->pic);
 197
 198     c->pic.reference = 1;
 199     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
 200     if(avctx->get_buffer(avctx, &c->pic) < 0){
 201         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 202         return -1;
 203     }
 204
 205     outptr = c->pic.data[0]; // Output image pointer
 206
 207 #ifdef CONFIG_ZLIB
 208     zret = inflateReset(&(c->zstream));
 209     if (zret != Z_OK) {
 210         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
 211         return -1;
 212     }
 213     c->zstream.next_in = encoded;
 214     c->zstream.avail_in = len;
 215     c->zstream.next_out = c->decomp_buf;
 216     c->zstream.avail_out = c->decomp_size;
 217     zret = inflate(&(c->zstream), Z_FINISH);
 218     // Z_DATA_ERROR means empty picture
 219     if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
 220         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
 221         return -1;
 222     }
 223
 224
 225     if(zret != Z_DATA_ERROR)
 226         decode_rle(c, c->zstream.avail_out);
 227
 228     /* make the palette available on the way out */
 229     if (c->avctx->pix_fmt == PIX_FMT_PAL8) {
 230         memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE);
 231         if (c->avctx->palctrl->palette_changed) {
 232             c->pic.palette_has_changed = 1;
 233             c->avctx->palctrl->palette_changed = 0;
 234         }
 235     }
 236
 237 #else
 238     av_log(avctx, AV_LOG_ERROR, "BUG! Zlib support not compiled in frame decoder.\n");
 239     return -1;
 240 #endif
 241
 242     *data_size = sizeof(AVFrame);
 243     *(AVFrame*)data = c->pic;
 244
 245     /* always report that the buffer was completely consumed */
 246     return buf_size;
 247 }
 248
 249
 250
 251 /*
 252  *
 253  * Init tscc decoder
 254  *
 255  */
 256 static av_cold int decode_init(AVCodecContext *avctx)
 257 {
 258     CamtasiaContext * const c = avctx->priv_data;
 259     int zret; // Zlib return code
 260
 261     c->avctx = avctx;
 262
 263     c->pic.data[0] = NULL;
 264     c->height = avctx->height;
 265
 266     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
 267         return 1;
 268     }
 269
 270 #ifdef CONFIG_ZLIB
 271     // Needed if zlib unused or init aborted before inflateInit
 272     memset(&(c->zstream), 0, sizeof(z_stream));
 273 #else
 274     av_log(avctx, AV_LOG_ERROR, "Zlib support not compiled.\n");
 275     return 1;
 276 #endif
 277     switch(avctx->bits_per_coded_sample){
 278     case  8: avctx->pix_fmt = PIX_FMT_PAL8; break;
 279     case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
 280     case 24:
 281              avctx->pix_fmt = PIX_FMT_BGR24;
 282              break;
 283     case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
 284     default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
 285              return -1;
 286     }
 287     c->bpp = avctx->bits_per_coded_sample;
 288     c->decomp_size = (avctx->width * c->bpp + (avctx->width + 254) / 255 + 2) * avctx->height + 2;//RLE in the 'best' case
 289
 290     /* Allocate decompression buffer */
 291     if (c->decomp_size) {
 292         if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
 293             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 294             return 1;
 295         }
 296     }
 297
 298 #ifdef CONFIG_ZLIB
 299     c->zstream.zalloc = Z_NULL;
 300     c->zstream.zfree = Z_NULL;
 301     c->zstream.opaque = Z_NULL;
 302     zret = inflateInit(&(c->zstream));
 303     if (zret != Z_OK) {
 304         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 305         return 1;
 306     }
 307 #endif
 308
 309     return 0;
 310 }
 311
 312
 313
 314 /*
 315  *
 316  * Uninit tscc decoder
 317  *
 318  */
 319 static av_cold int decode_end(AVCodecContext *avctx)
 320 {
 321     CamtasiaContext * const c = avctx->priv_data;
 322
 323     av_freep(&c->decomp_buf);
 324
 325     if (c->pic.data[0])
 326         avctx->release_buffer(avctx, &c->pic);
 327 #ifdef CONFIG_ZLIB
 328     inflateEnd(&(c->zstream));
 329 #endif
 330
 331     return 0;
 332 }
 333
 334 AVCodec tscc_decoder = {
 335         "camtasia",
 336         CODEC_TYPE_VIDEO,
 337         CODEC_ID_TSCC,
 338         sizeof(CamtasiaContext),
 339         decode_init,
 340         NULL,
 341         decode_end,
 342         decode_frame,
 343         CODEC_CAP_DR1,
 344         .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
 345 };
 346