1 /*
2 * Audio and Video frame extraction
3 * Copyright (c) 2003 Fabrice Bellard
4 * Copyright (c) 2003 Michael Niedermayer
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "parser.h"
24 #include "aac_ac3_parser.h"
25 #include "adts_header.h"
26 #include "adts_parser.h"
27 #include "get_bits.h"
28 #include "mpeg4audio.h"
29
aac_sync(uint64_t state,AACAC3ParseContext * hdr_info,int * need_next_header,int * new_frame_start)30 static int aac_sync(uint64_t state, AACAC3ParseContext *hdr_info,
31 int *need_next_header, int *new_frame_start)
32 {
33 GetBitContext bits;
34 AACADTSHeaderInfo hdr;
35 int size;
36 union {
37 uint64_t u64;
38 uint8_t u8[8 + AV_INPUT_BUFFER_PADDING_SIZE];
39 } tmp;
40
41 tmp.u64 = av_be2ne64(state);
42 init_get_bits(&bits, tmp.u8 + 8 - AV_AAC_ADTS_HEADER_SIZE,
43 AV_AAC_ADTS_HEADER_SIZE * 8);
44
45 if ((size = ff_adts_header_parse(&bits, &hdr)) < 0)
46 return 0;
47 *need_next_header = 0;
48 *new_frame_start = 1;
49 hdr_info->sample_rate = hdr.sample_rate;
50 hdr_info->channels = ff_mpeg4audio_channels[hdr.chan_config];
51 hdr_info->samples = hdr.samples;
52 hdr_info->bit_rate = hdr.bit_rate;
53 return size;
54 }
55
aac_parse_init(AVCodecParserContext * s1)56 static av_cold int aac_parse_init(AVCodecParserContext *s1)
57 {
58 AACAC3ParseContext *s = s1->priv_data;
59 s->header_size = AV_AAC_ADTS_HEADER_SIZE;
60 s->sync = aac_sync;
61 return 0;
62 }
63
64
65 AVCodecParser ff_aac_parser = {
66 .codec_ids = { AV_CODEC_ID_AAC },
67 .priv_data_size = sizeof(AACAC3ParseContext),
68 .parser_init = aac_parse_init,
69 .parser_parse = ff_aac_ac3_parse,
70 .parser_close = ff_parse_close,
71 };
72