2 * Audio and Video frame extraction
3 * Copyright (c) 2003 Fabrice Bellard
4 * Copyright (c) 2003 Michael Niedermayer
6 * This file is part of FFmpeg.
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.
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.
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
24 #include "aac_ac3_parser.h"
25 #include "aac_parser.h"
26 #include "bitstream.h"
27 #include "mpeg4audio.h"
29 #define AAC_HEADER_SIZE 7
31 int ff_aac_parse_header(GetBitContext
*gbc
, AACADTSHeaderInfo
*hdr
)
33 int size
, rdb
, ch
, sr
;
36 if(get_bits(gbc
, 12) != 0xfff)
37 return AAC_AC3_PARSE_ERROR_SYNC
;
39 skip_bits1(gbc
); /* id */
40 skip_bits(gbc
, 2); /* layer */
41 crc_abs
= get_bits1(gbc
); /* protection_absent */
42 aot
= get_bits(gbc
, 2); /* profile_objecttype */
43 sr
= get_bits(gbc
, 4); /* sample_frequency_index */
44 if(!ff_mpeg4audio_sample_rates
[sr
])
45 return AAC_AC3_PARSE_ERROR_SAMPLE_RATE
;
46 skip_bits1(gbc
); /* private_bit */
47 ch
= get_bits(gbc
, 3); /* channel_configuration */
49 if(!ff_mpeg4audio_channels
[ch
])
50 return AAC_AC3_PARSE_ERROR_CHANNEL_CFG
;
52 skip_bits1(gbc
); /* original/copy */
53 skip_bits1(gbc
); /* home */
55 /* adts_variable_header */
56 skip_bits1(gbc
); /* copyright_identification_bit */
57 skip_bits1(gbc
); /* copyright_identification_start */
58 size
= get_bits(gbc
, 13); /* aac_frame_length */
59 if(size
< AAC_HEADER_SIZE
)
60 return AAC_AC3_PARSE_ERROR_FRAME_SIZE
;
62 skip_bits(gbc
, 11); /* adts_buffer_fullness */
63 rdb
= get_bits(gbc
, 2); /* number_of_raw_data_blocks_in_frame */
65 hdr
->object_type
= aot
+ 1;
66 hdr
->chan_config
= ch
;
67 hdr
->crc_absent
= crc_abs
;
68 hdr
->num_aac_frames
= rdb
+ 1;
69 hdr
->sampling_index
= sr
;
70 hdr
->sample_rate
= ff_mpeg4audio_sample_rates
[sr
];
71 hdr
->samples
= (rdb
+ 1) * 1024;
72 hdr
->bit_rate
= size
* 8 * hdr
->sample_rate
/ hdr
->samples
;
77 static int aac_sync(uint64_t state
, AACAC3ParseContext
*hdr_info
,
78 int *need_next_header
, int *new_frame_start
)
81 AACADTSHeaderInfo hdr
;
88 tmp
.u64
= be2me_64(state
);
89 init_get_bits(&bits
, tmp
.u8
+8-AAC_HEADER_SIZE
, AAC_HEADER_SIZE
* 8);
91 if ((size
= ff_aac_parse_header(&bits
, &hdr
)) < 0)
93 *need_next_header
= 0;
95 hdr_info
->sample_rate
= hdr
.sample_rate
;
96 hdr_info
->channels
= ff_mpeg4audio_channels
[hdr
.chan_config
];
97 hdr_info
->samples
= hdr
.samples
;
98 hdr_info
->bit_rate
= hdr
.bit_rate
;
102 static av_cold
int aac_parse_init(AVCodecParserContext
*s1
)
104 AACAC3ParseContext
*s
= s1
->priv_data
;
105 s
->header_size
= AAC_HEADER_SIZE
;
111 AVCodecParser aac_parser
= {
113 sizeof(AACAC3ParseContext
),