2 * MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration bitstream filter
3 * Copyright (c) 2009 Alex Converse <alex.converse@gmail.com>
5 * This file is part of FFmpeg.
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.
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.
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
23 #include "aacadtsdec.h"
26 #include "mpeg4audio.h"
29 typedef struct AACBSFContext
{
34 * This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
35 * ADTS header and removes the ADTS header.
37 static int aac_adtstoasc_filter(AVBitStreamFilterContext
*bsfc
,
38 AVCodecContext
*avctx
, const char *args
,
39 uint8_t **poutbuf
, int *poutbuf_size
,
40 const uint8_t *buf
, int buf_size
,
45 AACADTSHeaderInfo hdr
;
47 AACBSFContext
*ctx
= bsfc
->priv_data
;
49 init_get_bits(&gb
, buf
, AAC_ADTS_HEADER_SIZE
*8);
51 *poutbuf
= (uint8_t*) buf
;
52 *poutbuf_size
= buf_size
;
55 if (show_bits(&gb
, 12) != 0xfff)
58 if (avpriv_aac_parse_header(&gb
, &hdr
) < 0) {
59 av_log(avctx
, AV_LOG_ERROR
, "Error parsing ADTS frame header!\n");
60 return AVERROR_INVALIDDATA
;
63 if (!hdr
.crc_absent
&& hdr
.num_aac_frames
> 1) {
64 avpriv_report_missing_feature(avctx
,
65 "Multiple RDBs per frame with CRC");
66 return AVERROR_PATCHWELCOME
;
69 buf
+= AAC_ADTS_HEADER_SIZE
+ 2*!hdr
.crc_absent
;
70 buf_size
-= AAC_ADTS_HEADER_SIZE
+ 2*!hdr
.crc_absent
;
72 if (!ctx
->first_frame_done
) {
74 uint8_t pce_data
[MAX_PCE_SIZE
];
75 if (!hdr
.chan_config
) {
76 init_get_bits(&gb
, buf
, buf_size
* 8);
77 if (get_bits(&gb
, 3) != 5) {
78 avpriv_report_missing_feature(avctx
,
79 "PCE-based channel configuration "
80 "without PCE as first syntax "
82 return AVERROR_PATCHWELCOME
;
84 init_put_bits(&pb
, pce_data
, MAX_PCE_SIZE
);
85 pce_size
= avpriv_copy_pce_data(&pb
, &gb
)/8;
87 buf_size
-= get_bits_count(&gb
)/8;
88 buf
+= get_bits_count(&gb
)/8;
90 av_free(avctx
->extradata
);
91 avctx
->extradata_size
= 2 + pce_size
;
92 avctx
->extradata
= av_mallocz(avctx
->extradata_size
+ FF_INPUT_BUFFER_PADDING_SIZE
);
94 init_put_bits(&pb
, avctx
->extradata
, avctx
->extradata_size
);
95 put_bits(&pb
, 5, hdr
.object_type
);
96 put_bits(&pb
, 4, hdr
.sampling_index
);
97 put_bits(&pb
, 4, hdr
.chan_config
);
98 put_bits(&pb
, 1, 0); //frame length - 1024 samples
99 put_bits(&pb
, 1, 0); //does not depend on core coder
100 put_bits(&pb
, 1, 0); //is not extension
103 memcpy(avctx
->extradata
+ 2, pce_data
, pce_size
);
106 ctx
->first_frame_done
= 1;
109 *poutbuf
= (uint8_t*) buf
;
110 *poutbuf_size
= buf_size
;
115 AVBitStreamFilter ff_aac_adtstoasc_bsf
= {
116 .name
= "aac_adtstoasc",
117 .priv_data_size
= sizeof(AACBSFContext
),
118 .filter
= aac_adtstoasc_filter
,