libavcodec/tscc.c

   1 /*
   2  * TechSmith Camtasia decoder
   3  * Copyright (c) 2004 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  51     // Bits per pixel
  52     int bpp;
  53     // Decompressed data size
  54     unsigned int decomp_size;
  55     // Decompression buffer
  56     unsigned char* decomp_buf;
  57     GetByteContext gb;
  58     int height;
  59     z_stream zstream;
  60
  61     uint32_t pal[256];
  62 } CamtasiaContext;
  63
  64 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  65                         AVPacket *avpkt)
  66 {
  67     const uint8_t *buf = avpkt->data;
  68     int buf_size = avpkt->size;
  69     CamtasiaContext * const c = avctx->priv_data;
  70     const unsigned char *encoded = buf;
  71     AVFrame *frame = data;
  72     int zret; // Zlib return code
  73     int ret, len = buf_size;
  74
  75     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0){
  76         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  77         return ret;
  78     }
  79
  80     zret = inflateReset(&c->zstream);
  81     if (zret != Z_OK) {
  82         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
  83         return AVERROR_UNKNOWN;
  84     }
  85     c->zstream.next_in = encoded;
  86     c->zstream.avail_in = len;
  87     c->zstream.next_out = c->decomp_buf;
  88     c->zstream.avail_out = c->decomp_size;
  89     zret = inflate(&c->zstream, Z_FINISH);
  90     // Z_DATA_ERROR means empty picture
  91     if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
  92         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
  93         return AVERROR_UNKNOWN;
  94     }
  95
  96
  97     if (zret != Z_DATA_ERROR) {
  98         bytestream2_init(&c->gb, c->decomp_buf,
  99                          c->decomp_size - c->zstream.avail_out);
 100         ff_msrle_decode(avctx, (AVPicture*)frame, c->bpp, &c->gb);
 101     }
 102
 103     /* make the palette available on the way out */
 104     if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
 105         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 106
 107         if (pal) {
 108             frame->palette_has_changed = 1;
 109             memcpy(c->pal, pal, AVPALETTE_SIZE);
 110         }
 111         memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
 112     }
 113
 114     *got_frame      = 1;
 115
 116     /* always report that the buffer was completely consumed */
 117     return buf_size;
 118 }
 119
 120 static av_cold int decode_init(AVCodecContext *avctx)
 121 {
 122     CamtasiaContext * const c = avctx->priv_data;
 123     int zret; // Zlib return code
 124
 125     c->avctx = avctx;
 126
 127     c->height = avctx->height;
 128
 129     // Needed if zlib unused or init aborted before inflateInit
 130     memset(&c->zstream, 0, sizeof(z_stream));
 131     switch(avctx->bits_per_coded_sample){
 132     case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
 133     case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
 134     case 24:
 135              avctx->pix_fmt = AV_PIX_FMT_BGR24;
 136              break;
 137     case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
 138     default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
 139              return AVERROR_INVALIDDATA;
 140     }
 141     c->bpp = avctx->bits_per_coded_sample;
 142     // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
 143     c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
 144
 145     /* Allocate decompression buffer */
 146     if (c->decomp_size) {
 147         if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
 148             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
 149             return AVERROR(ENOMEM);
 150         }
 151     }
 152
 153     c->zstream.zalloc = Z_NULL;
 154     c->zstream.zfree = Z_NULL;
 155     c->zstream.opaque = Z_NULL;
 156     zret = inflateInit(&c->zstream);
 157     if (zret != Z_OK) {
 158         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 159         return AVERROR_UNKNOWN;
 160     }
 161
 162     return 0;
 163 }
 164
 165 static av_cold int decode_end(AVCodecContext *avctx)
 166 {
 167     CamtasiaContext * const c = avctx->priv_data;
 168
 169     av_freep(&c->decomp_buf);
 170
 171     inflateEnd(&c->zstream);
 172
 173     return 0;
 174 }
 175
 176 AVCodec ff_tscc_decoder = {
 177     .name           = "camtasia",
 178     .type           = AVMEDIA_TYPE_VIDEO,
 179     .id             = AV_CODEC_ID_TSCC,
 180     .priv_data_size = sizeof(CamtasiaContext),
 181     .init           = decode_init,
 182     .close          = decode_end,
 183     .decode         = decode_frame,
 184     .capabilities   = CODEC_CAP_DR1,
 185     .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
 186 };