Libav
tscc.c
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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 
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 
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;
58  int height;
59  z_stream zstream;
60 
61  uint32_t pal[256];
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) {
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) {
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 
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 
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 
177  .name = "camtasia",
178  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
179  .type = AVMEDIA_TYPE_VIDEO,
180  .id = AV_CODEC_ID_TSCC,
181  .priv_data_size = sizeof(CamtasiaContext),
182  .init = decode_init,
183  .close = decode_end,
184  .decode = decode_frame,
185  .capabilities = CODEC_CAP_DR1,
186 };