path: root/libavcodec/xma_parser.c (plain)
blob: 05136792726edf3f0142feda9c49597cb46e6f3c

1	/*
2	* This file is part of FFmpeg.
3	*
4	* FFmpeg is free software; you can redistribute it and/or
5	* modify it under the terms of the GNU Lesser General Public
6	* License as published by the Free Software Foundation; either
7	* version 2.1 of the License, or (at your option) any later version.
8	*
9	* FFmpeg is distributed in the hope that it will be useful,
10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12	* Lesser General Public License for more details.
13	*
14	* You should have received a copy of the GNU Lesser General Public
15	* License along with FFmpeg; if not, write to the Free Software
16	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17	*/
18
19	/**
20	* @file
21	* XMA2 audio parser
22	*/
23
24	#include "parser.h"
25
26	typedef struct XMAParserContext{
27	int skip_packets;
28	} XMAParserContext;
29
30	static int xma_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
31	const uint8_t **poutbuf, int *poutbuf_size,
32	const uint8_t *buf, int buf_size)
33	{
34	XMAParserContext *s = s1->priv_data;
35
36	if (buf_size % 2048 == 0) {
37	int duration = 0, packet, nb_packets = buf_size / 2048;
38
39	for (packet = 0; packet < nb_packets; packet++) {
40	if (s->skip_packets == 0) {
41	duration += buf[packet * 2048] * 128;
42	s->skip_packets = buf[packet * 2048 + 3] + 1;
43	}
44	s->skip_packets--;
45	}
46
47	s1->duration = duration;
48	s1->key_frame = !!duration;
49	}
50
51	/* always return the full packet. this parser isn't doing any splitting or
52	combining, only packet analysis */
53	*poutbuf = buf;
54	*poutbuf_size = buf_size;
55	return buf_size;
56	}
57
58	AVCodecParser ff_xma_parser = {
59	.codec_ids = { AV_CODEC_ID_XMA2 },
60	.priv_data_size = sizeof(XMAParserContext),
61	.parser_parse = xma_parse,
62	};
63