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
47 typedef struct TsccContext {
49 AVCodecContext *avctx;
53 // Decompressed data size
54 unsigned int decomp_size;
55 // Decompression buffer
56 unsigned char* decomp_buf;
64 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
67 const uint8_t *buf = avpkt->data;
68 int buf_size = avpkt->size;
69 CamtasiaContext * const c = avctx->priv_data;
70 AVFrame *frame = data;
73 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0){
74 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
78 ret = inflateReset(&c->zstream);
80 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
81 return AVERROR_UNKNOWN;
83 c->zstream.next_in = buf;
84 c->zstream.avail_in = buf_size;
85 c->zstream.next_out = c->decomp_buf;
86 c->zstream.avail_out = c->decomp_size;
87 ret = inflate(&c->zstream, Z_FINISH);
88 // Z_DATA_ERROR means empty picture
89 if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
90 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
91 return AVERROR_UNKNOWN;
95 if (ret != Z_DATA_ERROR) {
96 bytestream2_init(&c->gb, c->decomp_buf,
97 c->decomp_size - c->zstream.avail_out);
98 ff_msrle_decode(avctx, (AVPicture*)frame, c->bpp, &c->gb);
101 /* make the palette available on the way out */
102 if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
103 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
106 frame->palette_has_changed = 1;
107 memcpy(c->pal, pal, AVPALETTE_SIZE);
109 memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
114 /* always report that the buffer was completely consumed */
118 static av_cold int decode_init(AVCodecContext *avctx)
120 CamtasiaContext * const c = avctx->priv_data;
121 int zret; // Zlib return code
125 c->height = avctx->height;
127 // Needed if zlib unused or init aborted before inflateInit
128 memset(&c->zstream, 0, sizeof(z_stream));
129 switch(avctx->bits_per_coded_sample){
130 case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
131 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
133 avctx->pix_fmt = AV_PIX_FMT_BGR24;
135 case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
136 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
137 return AVERROR_INVALIDDATA;
139 c->bpp = avctx->bits_per_coded_sample;
140 // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
141 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
143 /* Allocate decompression buffer */
144 if (c->decomp_size) {
145 if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
146 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
147 return AVERROR(ENOMEM);
151 c->zstream.zalloc = Z_NULL;
152 c->zstream.zfree = Z_NULL;
153 c->zstream.opaque = Z_NULL;
154 zret = inflateInit(&c->zstream);
156 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
157 return AVERROR_UNKNOWN;
163 static av_cold int decode_end(AVCodecContext *avctx)
165 CamtasiaContext * const c = avctx->priv_data;
167 av_freep(&c->decomp_buf);
169 inflateEnd(&c->zstream);
174 AVCodec ff_tscc_decoder = {
176 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
177 .type = AVMEDIA_TYPE_VIDEO,
178 .id = AV_CODEC_ID_TSCC,
179 .priv_data_size = sizeof(CamtasiaContext),
182 .decode = decode_frame,
183 .capabilities = CODEC_CAP_DR1,