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;
54 // Decompressed data size
55 unsigned int decomp_size;
56 // Decompression buffer
57 unsigned char* decomp_buf;
65 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
68 const uint8_t *buf = avpkt->data;
69 int buf_size = avpkt->size;
70 CamtasiaContext * const c = avctx->priv_data;
71 const unsigned char *encoded = buf;
72 int zret; // Zlib return code
73 int ret, len = buf_size;
76 avctx->release_buffer(avctx, &c->pic);
79 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
80 if ((ret = ff_get_buffer(avctx, &c->pic)) < 0){
81 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
85 zret = inflateReset(&c->zstream);
87 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
88 return AVERROR_UNKNOWN;
90 c->zstream.next_in = encoded;
91 c->zstream.avail_in = len;
92 c->zstream.next_out = c->decomp_buf;
93 c->zstream.avail_out = c->decomp_size;
94 zret = inflate(&c->zstream, Z_FINISH);
95 // Z_DATA_ERROR means empty picture
96 if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
97 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
98 return AVERROR_UNKNOWN;
102 if (zret != Z_DATA_ERROR) {
103 bytestream2_init(&c->gb, c->decomp_buf,
104 c->decomp_size - c->zstream.avail_out);
105 ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, &c->gb);
108 /* make the palette available on the way out */
109 if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
110 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
113 c->pic.palette_has_changed = 1;
114 memcpy(c->pal, pal, AVPALETTE_SIZE);
116 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
120 *(AVFrame*)data = c->pic;
122 /* always report that the buffer was completely consumed */
126 static av_cold int decode_init(AVCodecContext *avctx)
128 CamtasiaContext * const c = avctx->priv_data;
129 int zret; // Zlib return code
133 c->height = avctx->height;
135 // Needed if zlib unused or init aborted before inflateInit
136 memset(&c->zstream, 0, sizeof(z_stream));
137 switch(avctx->bits_per_coded_sample){
138 case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
139 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
141 avctx->pix_fmt = AV_PIX_FMT_BGR24;
143 case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
144 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
145 return AVERROR_INVALIDDATA;
147 c->bpp = avctx->bits_per_coded_sample;
148 // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
149 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
151 /* Allocate decompression buffer */
152 if (c->decomp_size) {
153 if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
154 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
155 return AVERROR(ENOMEM);
159 c->zstream.zalloc = Z_NULL;
160 c->zstream.zfree = Z_NULL;
161 c->zstream.opaque = Z_NULL;
162 zret = inflateInit(&c->zstream);
164 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
165 return AVERROR_UNKNOWN;
171 static av_cold int decode_end(AVCodecContext *avctx)
173 CamtasiaContext * const c = avctx->priv_data;
175 av_freep(&c->decomp_buf);
178 avctx->release_buffer(avctx, &c->pic);
179 inflateEnd(&c->zstream);
184 AVCodec ff_tscc_decoder = {
186 .type = AVMEDIA_TYPE_VIDEO,
187 .id = AV_CODEC_ID_TSCC,
188 .priv_data_size = sizeof(CamtasiaContext),
191 .decode = decode_frame,
192 .capabilities = CODEC_CAP_DR1,
193 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),