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tscc.c
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1 /*
2  * TechSmith Camtasia decoder
3  * Copyright (c) 2004 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * TechSmith Camtasia decoder
25  *
26  * Fourcc: TSCC
27  *
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
33  *
34  * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
35  *
36  */
37 
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 
51 
52  // Bits per pixel
53  int bpp;
54  // Decompressed data size
55  unsigned int decomp_size;
56  // Decompression buffer
57  unsigned char* decomp_buf;
59  int height;
60  z_stream zstream;
61 
62  uint32_t pal[256];
64 
65 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
66  AVPacket *avpkt)
67 {
68  const uint8_t *buf = avpkt->data;
69  int buf_size = avpkt->size;
70  CamtasiaContext * const c = avctx->priv_data;
71  AVFrame *frame = c->frame;
72  int ret;
73 
74  if ((ret = ff_reget_buffer(avctx, frame)) < 0)
75  return ret;
76 
77  ret = inflateReset(&c->zstream);
78  if (ret != Z_OK) {
79  av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
80  return AVERROR_UNKNOWN;
81  }
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;
91  }
92 
93 
94  if (ret != Z_DATA_ERROR) {
96  c->decomp_size - c->zstream.avail_out);
97  ff_msrle_decode(avctx, (AVPicture*)frame, c->bpp, &c->gb);
98  }
99 
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);
103 
104  if (pal) {
105  frame->palette_has_changed = 1;
106  memcpy(c->pal, pal, AVPALETTE_SIZE);
107  }
108  memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
109  }
110 
111  if ((ret = av_frame_ref(data, frame)) < 0)
112  return ret;
113  *got_frame = 1;
114 
115  /* always report that the buffer was completely consumed */
116  return buf_size;
117 }
118 
120 {
121  CamtasiaContext * const c = avctx->priv_data;
122  int zret; // Zlib return code
123 
124  c->avctx = avctx;
125 
126  c->height = avctx->height;
127 
128  // Needed if zlib unused or init aborted before inflateInit
129  memset(&c->zstream, 0, sizeof(z_stream));
130  switch(avctx->bits_per_coded_sample){
131  case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
132  case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
133  case 24:
134  avctx->pix_fmt = AV_PIX_FMT_BGR24;
135  break;
136  case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
137  default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
138  return AVERROR_PATCHWELCOME;
139  }
140  c->bpp = avctx->bits_per_coded_sample;
141  // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
142  c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
143 
144  /* Allocate decompression buffer */
145  if (c->decomp_size) {
146  if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
147  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
148  return AVERROR(ENOMEM);
149  }
150  }
151 
152  c->zstream.zalloc = Z_NULL;
153  c->zstream.zfree = Z_NULL;
154  c->zstream.opaque = Z_NULL;
155  zret = inflateInit(&c->zstream);
156  if (zret != Z_OK) {
157  av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
158  return AVERROR_UNKNOWN;
159  }
160 
161  c->frame = av_frame_alloc();
162 
163  return 0;
164 }
165 
167 {
168  CamtasiaContext * const c = avctx->priv_data;
169 
170  av_freep(&c->decomp_buf);
171  av_frame_free(&c->frame);
172 
173  inflateEnd(&c->zstream);
174 
175  return 0;
176 }
177 
179  .name = "camtasia",
180  .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
181  .type = AVMEDIA_TYPE_VIDEO,
182  .id = AV_CODEC_ID_TSCC,
183  .priv_data_size = sizeof(CamtasiaContext),
184  .init = decode_init,
185  .close = decode_end,
186  .decode = decode_frame,
187  .capabilities = CODEC_CAP_DR1,
188 };