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 "msrledec.h"
43 
44 #include <zlib.h>
45 
46 
47 /*
48  * Decoder context
49  */
50 typedef struct TsccContext {
51 
54 
55  // Bits per pixel
56  int bpp;
57  // Decompressed data size
58  unsigned int decomp_size;
59  // Decompression buffer
60  unsigned char* decomp_buf;
61  int height;
62  z_stream zstream;
63 
64  uint32_t pal[256];
66 
67 /*
68  *
69  * Decode a frame
70  *
71  */
72 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
73 {
74  const uint8_t *buf = avpkt->data;
75  int buf_size = avpkt->size;
76  CamtasiaContext * const c = avctx->priv_data;
77  const unsigned char *encoded = buf;
78  int zret; // Zlib return code
79  int len = buf_size;
80 
81  if(c->pic.data[0])
82  avctx->release_buffer(avctx, &c->pic);
83 
84  c->pic.reference = 1;
86  if(avctx->get_buffer(avctx, &c->pic) < 0){
87  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
88  return -1;
89  }
90 
91  zret = inflateReset(&c->zstream);
92  if (zret != Z_OK) {
93  av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
94  return -1;
95  }
96  c->zstream.next_in = encoded;
97  c->zstream.avail_in = len;
98  c->zstream.next_out = c->decomp_buf;
99  c->zstream.avail_out = c->decomp_size;
100  zret = inflate(&c->zstream, Z_FINISH);
101  // Z_DATA_ERROR means empty picture
102  if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
103  av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
104  return -1;
105  }
106 
107 
108  if(zret != Z_DATA_ERROR)
109  ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->decomp_size - c->zstream.avail_out);
110 
111  /* make the palette available on the way out */
112  if (c->avctx->pix_fmt == PIX_FMT_PAL8) {
113  const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
114 
115  if (pal) {
116  c->pic.palette_has_changed = 1;
117  memcpy(c->pal, pal, AVPALETTE_SIZE);
118  }
119  memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
120  }
121 
122  *data_size = sizeof(AVFrame);
123  *(AVFrame*)data = c->pic;
124 
125  /* always report that the buffer was completely consumed */
126  return buf_size;
127 }
128 
129 
130 
131 /*
132  *
133  * Init tscc decoder
134  *
135  */
137 {
138  CamtasiaContext * const c = avctx->priv_data;
139  int zret; // Zlib return code
140 
141  c->avctx = avctx;
142 
143  c->height = avctx->height;
144 
145  // Needed if zlib unused or init aborted before inflateInit
146  memset(&c->zstream, 0, sizeof(z_stream));
147  switch(avctx->bits_per_coded_sample){
148  case 8: avctx->pix_fmt = PIX_FMT_PAL8; break;
149  case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
150  case 24:
151  avctx->pix_fmt = PIX_FMT_BGR24;
152  break;
153  case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
154  default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
155  return -1;
156  }
157  c->bpp = avctx->bits_per_coded_sample;
158  // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
159  c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
160 
161  /* Allocate decompression buffer */
162  if (c->decomp_size) {
163  if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
164  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
165  return 1;
166  }
167  }
168 
169  c->zstream.zalloc = Z_NULL;
170  c->zstream.zfree = Z_NULL;
171  c->zstream.opaque = Z_NULL;
172  zret = inflateInit(&c->zstream);
173  if (zret != Z_OK) {
174  av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
175  return 1;
176  }
177 
178  return 0;
179 }
180 
181 
182 
183 /*
184  *
185  * Uninit tscc decoder
186  *
187  */
189 {
190  CamtasiaContext * const c = avctx->priv_data;
191 
192  av_freep(&c->decomp_buf);
193 
194  if (c->pic.data[0])
195  avctx->release_buffer(avctx, &c->pic);
196  inflateEnd(&c->zstream);
197 
198  return 0;
199 }
200 
202  .name = "camtasia",
203  .type = AVMEDIA_TYPE_VIDEO,
204  .id = CODEC_ID_TSCC,
205  .priv_data_size = sizeof(CamtasiaContext),
206  .init = decode_init,
207  .close = decode_end,
208  .decode = decode_frame,
209  .capabilities = CODEC_CAP_DR1,
210  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
211 };
212