ffmpeg/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
  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 "internal.h"
  43 #include "msrledec.h"
  44
  45 #include <zlib.h>
  46
  47 typedef struct TsccContext {
  48
  49     AVCodecContext *avctx;
  50     AVFrame *frame;
  51
  52     // Bits per pixel
  53     int bpp;
  54     // Decompressed data size
  55     unsigned int decomp_size;
  56     // Decompression buffer
  57     unsigned char* decomp_buf;
  58     GetByteContext gb;
  59     int height;
  60     z_stream zstream;
  61
  62     uint32_t pal[256];
  63 } CamtasiaContext;
  64
  65 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  66                         AVPacket *avpkt)
  67 {
  68     const uint8_t *buf = avpkt->data;
  69     int buf_size = avpkt->size;
  70     CamtasiaContext * const c = avctx->priv_data;
  71     AVFrame *frame = c->frame;
  72     int ret;
  73
  74     if ((ret = ff_reget_buffer(avctx, frame)) < 0)
  75         return ret;
  76
  77     ret = inflateReset(&c->zstream);
  78     if (ret != Z_OK) {
  79         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
  80         return AVERROR_UNKNOWN;
  81     }
  82     c->zstream.next_in   = buf;
  83     c->zstream.avail_in  = buf_size;
  84     c->zstream.next_out = c->decomp_buf;
  85     c->zstream.avail_out = c->decomp_size;
  86     ret = inflate(&c->zstream, Z_FINISH);
  87     // Z_DATA_ERROR means empty picture
  88     if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
  89         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
  90         return AVERROR_UNKNOWN;
  91     }
  92
  93
  94     if (ret != Z_DATA_ERROR) {
  95         bytestream2_init(&c->gb, c->decomp_buf,
  96                          c->decomp_size - c->zstream.avail_out);
  97         ff_msrle_decode(avctx, (AVPicture*)frame, c->bpp, &c->gb);
  98     }
  99
 100     /* make the palette available on the way out */
 101     if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
 102         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 103
 104         if (pal) {
 105             frame->palette_has_changed = 1;
 106             memcpy(c->pal, pal, AVPALETTE_SIZE);
 107         }
 108         memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
 109     }
 110
 111     if ((ret = av_frame_ref(data, frame)) < 0)
 112         return ret;
 113     *got_frame      = 1;
 114
 115     /* always report that the buffer was completely consumed */
 116     return buf_size;
 117 }
 118
 119 static av_cold int decode_init(AVCodecContext *avctx)
 120 {
 121     CamtasiaContext * const c = avctx->priv_data;
 122     int zret; // Zlib return code
 123
 124     c->avctx = avctx;
 125
 126     c->height = avctx->height;
 127
 128     // Needed if zlib unused or init aborted before inflateInit
 129     memset(&c->zstream, 0, sizeof(z_stream));
 130     switch(avctx->bits_per_coded_sample){
 131     case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
 132     case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
 133     case 24:
 134              avctx->pix_fmt = AV_PIX_FMT_BGR24;
 135              break;
 136     case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
 137     default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
 138              return AVERROR_PATCHWELCOME;
 139     }
 140     c->bpp = avctx->bits_per_coded_sample;
 141     // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
 142     c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
 143
 144     /* Allocate decompression buffer */
 145     if (c->decomp_size) {
 146         if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
 147             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 148             return AVERROR(ENOMEM);
 149         }
 150     }
 151
 152     c->zstream.zalloc = Z_NULL;
 153     c->zstream.zfree = Z_NULL;
 154     c->zstream.opaque = Z_NULL;
 155     zret = inflateInit(&c->zstream);
 156     if (zret != Z_OK) {
 157         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 158         return AVERROR_UNKNOWN;
 159     }
 160
 161     c->frame = av_frame_alloc();
 162
 163     return 0;
 164 }
 165
 166 static av_cold int decode_end(AVCodecContext *avctx)
 167 {
 168     CamtasiaContext * const c = avctx->priv_data;
 169
 170     av_freep(&c->decomp_buf);
 171     av_frame_free(&c->frame);
 172
 173     inflateEnd(&c->zstream);
 174
 175     return 0;
 176 }
 177
 178 AVCodec ff_tscc_decoder = {
 179     .name           = "camtasia",
 180     .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
 181     .type           = AVMEDIA_TYPE_VIDEO,
 182     .id             = AV_CODEC_ID_TSCC,
 183     .priv_data_size = sizeof(CamtasiaContext),
 184     .init           = decode_init,
 185     .close          = decode_end,
 186     .decode         = decode_frame,
 187     .capabilities   = CODEC_CAP_DR1,
 188 };