path: root/libavcodec/tak_parser.c (plain)
blob: 835a47bd529cfc37c1add9b3e2112e410185a1c3

1	/*
2	* TAK parser
3	* Copyright (c) 2012 Michael Niedermayer
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	* TAK parser
25	**/
26
27	#define BITSTREAM_READER_LE
28	#include "parser.h"
29	#include "tak.h"
30
31	typedef struct TAKParseContext {
32	ParseContext pc;
33	TAKStreamInfo ti;
34	int index;
35	} TAKParseContext;
36
37	static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx,
38	const uint8_t **poutbuf, int *poutbuf_size,
39	const uint8_t *buf, int buf_size)
40	{
41	TAKParseContext *t = s->priv_data;
42	ParseContext *pc = &t->pc;
43	int next = END_NOT_FOUND;
44	GetBitContext gb;
45	int consumed = 0;
46	int needed = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
47	int ret;
48
49	if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
50	TAKStreamInfo ti;
51	if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
52	return ret;
53	if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
54	s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
55	: t->ti.frame_samples;
56	*poutbuf = buf;
57	*poutbuf_size = buf_size;
58	return buf_size;
59	}
60
61	while (buf_size || t->index + needed <= pc->index) {
62	if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
63	int tmp_buf_size = FFMIN(TAK_MAX_FRAME_HEADER_BYTES,
64	buf_size);
65	const uint8_t *tmp_buf = buf;
66
67	if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
68	return AVERROR(ENOMEM);
69	consumed += tmp_buf_size;
70	buf += tmp_buf_size;
71	buf_size -= tmp_buf_size;
72	}
73
74	for (; t->index + needed <= pc->index; t->index++) {
75	if (pc->buffer[ t->index ] == 0xFF &&
76	pc->buffer[ t->index + 1 ] == 0xA0) {
77	TAKStreamInfo ti;
78
79	if ((ret = init_get_bits8(&gb, pc->buffer + t->index,
80	pc->index - t->index)) < 0)
81	return ret;
82	if (!ff_tak_decode_frame_header(avctx, &gb,
83	pc->frame_start_found ? &ti : &t->ti, 127) &&
84	!ff_tak_check_crc(pc->buffer + t->index,
85	get_bits_count(&gb) / 8)) {
86	if (!pc->frame_start_found) {
87	pc->frame_start_found = 1;
88	s->duration = t->ti.last_frame_samples ?
89	t->ti.last_frame_samples :
90	t->ti.frame_samples;
91	s->key_frame = !!(t->ti.flags & TAK_FRAME_FLAG_HAS_INFO);
92	} else {
93	pc->frame_start_found = 0;
94	next = t->index - pc->index;
95	t->index = 0;
96	goto found;
97	}
98	}
99	}
100	}
101	}
102	found:
103
104	if (consumed && !buf_size && next == END_NOT_FOUND ||
105	ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
106	*poutbuf = NULL;
107	*poutbuf_size = 0;
108	return buf_size + consumed;
109	}
110
111	if (next != END_NOT_FOUND) {
112	next += consumed;
113	pc->overread = FFMAX(0, -next);
114	}
115
116	*poutbuf = buf;
117	*poutbuf_size = buf_size;
118	return next;
119	}
120
121	AVCodecParser ff_tak_parser = {
122	.codec_ids = { AV_CODEC_ID_TAK },
123	.priv_data_size = sizeof(TAKParseContext),
124	.parser_parse = tak_parse,
125	.parser_close = ff_parse_close,
126	};
127