path: root/libavcodec/tscc.c (plain)
blob: cb86b584c1dd1559e2489f93b880c02bccb73e05

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