1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
/*
* MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration bitstream filter
* Copyright (c) 2009 Alex Converse <alex.converse@gmail.com>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "adts_header.h"
#include "adts_parser.h"
#include "avcodec.h"
#include "bsf.h"
#include "put_bits.h"
#include "get_bits.h"
#include "mpeg4audio.h"
#include "internal.h"
typedef struct AACBSFContext {
int first_frame_done;
} AACBSFContext;
/**
* This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
* ADTS header and removes the ADTS header.
*/
static int aac_adtstoasc_filter(AVBSFContext *bsfc, AVPacket *out)
{
AACBSFContext *ctx = bsfc->priv_data;
GetBitContext gb;
PutBitContext pb;
AACADTSHeaderInfo hdr;
AVPacket *in;
int ret;
ret = ff_bsf_get_packet(bsfc, &in);
if (ret < 0)
return ret;
if (in->size < AV_AAC_ADTS_HEADER_SIZE)
goto packet_too_small;
init_get_bits(&gb, in->data, AV_AAC_ADTS_HEADER_SIZE * 8);
if (bsfc->par_in->extradata && show_bits(&gb, 12) != 0xfff)
goto finish;
if (ff_adts_header_parse(&gb, &hdr) < 0) {
av_log(bsfc, AV_LOG_ERROR, "Error parsing ADTS frame header!\n");
ret = AVERROR_INVALIDDATA;
goto fail;
}
if (!hdr.crc_absent && hdr.num_aac_frames > 1) {
avpriv_report_missing_feature(bsfc,
"Multiple RDBs per frame with CRC");
ret = AVERROR_PATCHWELCOME;
goto fail;
}
in->size -= AV_AAC_ADTS_HEADER_SIZE + 2 * !hdr.crc_absent;
if (in->size <= 0)
goto packet_too_small;
in->data += AV_AAC_ADTS_HEADER_SIZE + 2 * !hdr.crc_absent;
if (!ctx->first_frame_done) {
int pce_size = 0;
uint8_t pce_data[MAX_PCE_SIZE];
uint8_t *extradata;
if (!hdr.chan_config) {
init_get_bits(&gb, in->data, in->size * 8);
if (get_bits(&gb, 3) != 5) {
avpriv_report_missing_feature(bsfc,
"PCE-based channel configuration "
"without PCE as first syntax "
"element");
ret = AVERROR_PATCHWELCOME;
goto fail;
}
init_put_bits(&pb, pce_data, MAX_PCE_SIZE);
pce_size = ff_copy_pce_data(&pb, &gb) / 8;
flush_put_bits(&pb);
in->size -= get_bits_count(&gb)/8;
in->data += get_bits_count(&gb)/8;
}
extradata = av_packet_new_side_data(in, AV_PKT_DATA_NEW_EXTRADATA,
2 + pce_size);
if (!extradata) {
ret = AVERROR(ENOMEM);
goto fail;
}
init_put_bits(&pb, extradata, 2 + pce_size);
put_bits(&pb, 5, hdr.object_type);
put_bits(&pb, 4, hdr.sampling_index);
put_bits(&pb, 4, hdr.chan_config);
put_bits(&pb, 1, 0); //frame length - 1024 samples
put_bits(&pb, 1, 0); //does not depend on core coder
put_bits(&pb, 1, 0); //is not extension
flush_put_bits(&pb);
if (pce_size) {
memcpy(extradata + 2, pce_data, pce_size);
}
ctx->first_frame_done = 1;
}
finish:
av_packet_move_ref(out, in);
av_packet_free(&in);
return 0;
packet_too_small:
av_log(bsfc, AV_LOG_ERROR, "Input packet too small\n");
ret = AVERROR_INVALIDDATA;
fail:
av_packet_free(&in);
return ret;
}
static int aac_adtstoasc_init(AVBSFContext *ctx)
{
/* Validate the extradata if the stream is already MPEG-4 AudioSpecificConfig */
if (ctx->par_in->extradata) {
MPEG4AudioConfig mp4ac;
int ret = avpriv_mpeg4audio_get_config(&mp4ac, ctx->par_in->extradata,
ctx->par_in->extradata_size * 8, 1);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Error parsing AudioSpecificConfig extradata!\n");
return ret;
}
}
return 0;
}
static const enum AVCodecID codec_ids[] = {
AV_CODEC_ID_AAC, AV_CODEC_ID_NONE,
};
const AVBitStreamFilter ff_aac_adtstoasc_bsf = {
.name = "aac_adtstoasc",
.priv_data_size = sizeof(AACBSFContext),
.init = aac_adtstoasc_init,
.filter = aac_adtstoasc_filter,
.codec_ids = codec_ids,
};
|
