2 * TechSmith Camtasia decoder
3 * Copyright (c) 2004 Konstantin Shishkov
5 * This file is part of Libav.
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.
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.
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
24 * TechSmith Camtasia decoder
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
34 * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
46 typedef struct TsccContext {
48 AVCodecContext *avctx;
52 // Decompressed data size
53 unsigned int decomp_size;
54 // Decompression buffer
55 unsigned char* decomp_buf;
63 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
66 const uint8_t *buf = avpkt->data;
67 int buf_size = avpkt->size;
68 CamtasiaContext * const c = avctx->priv_data;
69 AVFrame *frame = data;
72 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0){
73 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
77 ret = inflateReset(&c->zstream);
79 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
80 return AVERROR_UNKNOWN;
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;
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, frame, c->bpp, &c->gb);
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);
105 frame->palette_has_changed = 1;
106 memcpy(c->pal, pal, AVPALETTE_SIZE);
108 memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
113 /* always report that the buffer was completely consumed */
117 static av_cold int decode_init(AVCodecContext *avctx)
119 CamtasiaContext * const c = avctx->priv_data;
120 int zret; // Zlib return code
124 c->height = avctx->height;
126 // Needed if zlib unused or init aborted before inflateInit
127 memset(&c->zstream, 0, sizeof(z_stream));
128 switch(avctx->bits_per_coded_sample){
129 case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
130 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
132 avctx->pix_fmt = AV_PIX_FMT_BGR24;
134 case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
135 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
136 return AVERROR_INVALIDDATA;
138 c->bpp = avctx->bits_per_coded_sample;
139 // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
140 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
142 /* Allocate decompression buffer */
143 if (c->decomp_size) {
144 if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
145 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
146 return AVERROR(ENOMEM);
150 c->zstream.zalloc = Z_NULL;
151 c->zstream.zfree = Z_NULL;
152 c->zstream.opaque = Z_NULL;
153 zret = inflateInit(&c->zstream);
155 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
156 return AVERROR_UNKNOWN;
162 static av_cold int decode_end(AVCodecContext *avctx)
164 CamtasiaContext * const c = avctx->priv_data;
166 av_freep(&c->decomp_buf);
168 inflateEnd(&c->zstream);
173 AVCodec ff_tscc_decoder = {
175 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
176 .type = AVMEDIA_TYPE_VIDEO,
177 .id = AV_CODEC_ID_TSCC,
178 .priv_data_size = sizeof(CamtasiaContext),
181 .decode = decode_frame,
182 .capabilities = AV_CODEC_CAP_DR1,