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 libavcodec/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 #include "msrledec.h"
  43
  44 #include <zlib.h>
  45
  46
  47 /*
  48  * Decoder context
  49  */
  50 typedef struct TsccContext {
  51
  52     AVCodecContext *avctx;
  53     AVFrame pic;
  54
  55     // Bits per pixel
  56     int bpp;
  57     // Decompressed data size
  58     unsigned int decomp_size;
  59     // Decompression buffer
  60     unsigned char* decomp_buf;
  61     int height;
  62     z_stream zstream;
  63 } CamtasiaContext;
  64
  65 /*
  66  *
  67  * Decode a frame
  68  *
  69  */
  70 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
  71 {
  72     CamtasiaContext * const c = avctx->priv_data;
  73     const unsigned char *encoded = buf;
  74     unsigned char *outptr;
  75     int zret; // Zlib return code
  76     int len = buf_size;
  77
  78     if(c->pic.data[0])
  79             avctx->release_buffer(avctx, &c->pic);
  80
  81     c->pic.reference = 1;
  82     c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
  83     if(avctx->get_buffer(avctx, &c->pic) < 0){
  84         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  85         return -1;
  86     }
  87
  88     outptr = c->pic.data[0]; // Output image pointer
  89
  90     zret = inflateReset(&(c->zstream));
  91     if (zret != Z_OK) {
  92         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
  93         return -1;
  94     }
  95     c->zstream.next_in = encoded;
  96     c->zstream.avail_in = len;
  97     c->zstream.next_out = c->decomp_buf;
  98     c->zstream.avail_out = c->decomp_size;
  99     zret = inflate(&(c->zstream), Z_FINISH);
 100     // Z_DATA_ERROR means empty picture
 101     if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
 102         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
 103         return -1;
 104     }
 105
 106
 107     if(zret != Z_DATA_ERROR)
 108         ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->zstream.avail_out);
 109
 110     /* make the palette available on the way out */
 111     if (c->avctx->pix_fmt == PIX_FMT_PAL8) {
 112         memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE);
 113         if (c->avctx->palctrl->palette_changed) {
 114             c->pic.palette_has_changed = 1;
 115             c->avctx->palctrl->palette_changed = 0;
 116         }
 117     }
 118
 119     *data_size = sizeof(AVFrame);
 120     *(AVFrame*)data = c->pic;
 121
 122     /* always report that the buffer was completely consumed */
 123     return buf_size;
 124 }
 125
 126
 127
 128 /*
 129  *
 130  * Init tscc decoder
 131  *
 132  */
 133 static av_cold int decode_init(AVCodecContext *avctx)
 134 {
 135     CamtasiaContext * const c = avctx->priv_data;
 136     int zret; // Zlib return code
 137
 138     c->avctx = avctx;
 139
 140     c->pic.data[0] = NULL;
 141     c->height = avctx->height;
 142
 143     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
 144         return 1;
 145     }
 146
 147     // Needed if zlib unused or init aborted before inflateInit
 148     memset(&(c->zstream), 0, sizeof(z_stream));
 149     switch(avctx->bits_per_coded_sample){
 150     case  8: avctx->pix_fmt = PIX_FMT_PAL8; break;
 151     case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
 152     case 24:
 153              avctx->pix_fmt = PIX_FMT_BGR24;
 154              break;
 155     case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
 156     default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
 157              return -1;
 158     }
 159     c->bpp = avctx->bits_per_coded_sample;
 160     c->decomp_size = (avctx->width * c->bpp + (avctx->width + 254) / 255 + 2) * avctx->height + 2;//RLE in the 'best' case
 161
 162     /* Allocate decompression buffer */
 163     if (c->decomp_size) {
 164         if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
 165             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 166             return 1;
 167         }
 168     }
 169
 170     c->zstream.zalloc = Z_NULL;
 171     c->zstream.zfree = Z_NULL;
 172     c->zstream.opaque = Z_NULL;
 173     zret = inflateInit(&(c->zstream));
 174     if (zret != Z_OK) {
 175         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 176         return 1;
 177     }
 178
 179     return 0;
 180 }
 181
 182
 183
 184 /*
 185  *
 186  * Uninit tscc decoder
 187  *
 188  */
 189 static av_cold int decode_end(AVCodecContext *avctx)
 190 {
 191     CamtasiaContext * const c = avctx->priv_data;
 192
 193     av_freep(&c->decomp_buf);
 194
 195     if (c->pic.data[0])
 196         avctx->release_buffer(avctx, &c->pic);
 197     inflateEnd(&(c->zstream));
 198
 199     return 0;
 200 }
 201
 202 AVCodec tscc_decoder = {
 203         "camtasia",
 204         CODEC_TYPE_VIDEO,
 205         CODEC_ID_TSCC,
 206         sizeof(CamtasiaContext),
 207         decode_init,
 208         NULL,
 209         decode_end,
 210         decode_frame,
 211         CODEC_CAP_DR1,
 212         .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
 213 };
 214