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 #include <stdio.h>
38 #include <stdlib.h>
39
40 #include "avcodec.h"
41 #include "internal.h"
42 #include "msrledec.h"
43
44 #include <zlib.h>
45
46 typedef struct TsccContext {
47
48 AVCodecContext *avctx;
49 AVFrame *frame;
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;
57 GetByteContext gb;
58 int height;
59 z_stream zstream;
60
61 uint32_t pal[256];
62 } CamtasiaContext;
63
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)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 AVFrame *frame = c->frame;
71 int ret;
72 int palette_has_changed = 0;
73
74 if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
75 buffer_size_t size;
76 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &size);
77
78 if (pal && size == AVPALETTE_SIZE) {
79 palette_has_changed = 1;
80 memcpy(c->pal, pal, AVPALETTE_SIZE);
81 } else if (pal) {
82 av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);
83 }
84 }
85
86 ret = inflateReset(&c->zstream);
87 if (ret != Z_OK) {
88 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
89 return AVERROR_UNKNOWN;
90 }
91 c->zstream.next_in = buf;
92 c->zstream.avail_in = buf_size;
93 c->zstream.next_out = c->decomp_buf;
94 c->zstream.avail_out = c->decomp_size;
95 ret = inflate(&c->zstream, Z_FINISH);
96 // Z_DATA_ERROR means empty picture
97 if (ret == Z_DATA_ERROR && !palette_has_changed) {
98 return buf_size;
99 }
100
101 if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
102 av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
103 return AVERROR_UNKNOWN;
104 }
105
106 if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
107 return ret;
108
109 if (ret != Z_DATA_ERROR) {
110 bytestream2_init(&c->gb, c->decomp_buf,
111 c->decomp_size - c->zstream.avail_out);
112 ff_msrle_decode(avctx, frame, c->bpp, &c->gb);
113 }
114
115 /* make the palette available on the way out */
116 if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
117 frame->palette_has_changed = palette_has_changed;
118 memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
119 }
120
121 if ((ret = av_frame_ref(data, frame)) < 0)
122 return ret;
123 *got_frame = 1;
124
125 /* always report that the buffer was completely consumed */
126 return buf_size;
127 }
128
decode_init(AVCodecContext * avctx)129 static av_cold int decode_init(AVCodecContext *avctx)
130 {
131 CamtasiaContext * const c = avctx->priv_data;
132 int zret; // Zlib return code
133
134 c->avctx = avctx;
135
136 c->height = avctx->height;
137
138 // Needed if zlib unused or init aborted before inflateInit
139 memset(&c->zstream, 0, sizeof(z_stream));
140 switch(avctx->bits_per_coded_sample){
141 case 8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
142 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
143 case 24:
144 avctx->pix_fmt = AV_PIX_FMT_BGR24;
145 break;
146 case 32: avctx->pix_fmt = AV_PIX_FMT_0RGB32; break;
147 default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
148 return AVERROR_PATCHWELCOME;
149 }
150 c->bpp = avctx->bits_per_coded_sample;
151 // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
152 c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
153
154 /* Allocate decompression buffer */
155 if (c->decomp_size) {
156 if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
157 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
158 return AVERROR(ENOMEM);
159 }
160 }
161
162 c->zstream.zalloc = Z_NULL;
163 c->zstream.zfree = Z_NULL;
164 c->zstream.opaque = Z_NULL;
165 zret = inflateInit(&c->zstream);
166 if (zret != Z_OK) {
167 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
168 return AVERROR_UNKNOWN;
169 }
170
171 c->frame = av_frame_alloc();
172 if (!c->frame)
173 return AVERROR(ENOMEM);
174
175 return 0;
176 }
177
decode_end(AVCodecContext * avctx)178 static av_cold int decode_end(AVCodecContext *avctx)
179 {
180 CamtasiaContext * const c = avctx->priv_data;
181
182 av_freep(&c->decomp_buf);
183 av_frame_free(&c->frame);
184
185 inflateEnd(&c->zstream);
186
187 return 0;
188 }
189
190 AVCodec ff_tscc_decoder = {
191 .name = "camtasia",
192 .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
193 .type = AVMEDIA_TYPE_VIDEO,
194 .id = AV_CODEC_ID_TSCC,
195 .priv_data_size = sizeof(CamtasiaContext),
196 .init = decode_init,
197 .close = decode_end,
198 .decode = decode_frame,
199 .capabilities = AV_CODEC_CAP_DR1,
200 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
201 };
202