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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
* ADTS muxer.
* Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
* Mans Rullgard <mans@mansr.com>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavcodec/get_bits.h"
#include "libavcodec/put_bits.h"
#include "libavcodec/avcodec.h"
#include "libavcodec/mpeg4audio.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include "apetag.h"
#include "id3v2.h"
#define ADTS_HEADER_SIZE 7
typedef struct ADTSContext {
AVClass *class;
int write_adts;
int objecttype;
int sample_rate_index;
int channel_conf;
int pce_size;
int apetag;
int id3v2tag;
uint8_t pce_data[MAX_PCE_SIZE];
} ADTSContext;
#define ADTS_MAX_FRAME_BYTES ((1 << 13) - 1)
static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, const uint8_t *buf, int size)
{
GetBitContext gb;
PutBitContext pb;
MPEG4AudioConfig m4ac;
int off, ret;
ret = init_get_bits8(&gb, buf, size);
if (ret < 0)
return ret;
off = avpriv_mpeg4audio_get_config2(&m4ac, buf, size, 1, s);
if (off < 0)
return off;
skip_bits_long(&gb, off);
adts->objecttype = m4ac.object_type - 1;
adts->sample_rate_index = m4ac.sampling_index;
adts->channel_conf = m4ac.chan_config;
if (adts->objecttype > 3U) {
av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1);
return AVERROR_INVALIDDATA;
}
if (adts->sample_rate_index == 15) {
av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n");
return AVERROR_INVALIDDATA;
}
if (get_bits(&gb, 1)) {
av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n");
return AVERROR_INVALIDDATA;
}
if (get_bits(&gb, 1)) {
av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n");
return AVERROR_INVALIDDATA;
}
if (get_bits(&gb, 1)) {
av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n");
return AVERROR_INVALIDDATA;
}
if (!adts->channel_conf) {
init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE);
put_bits(&pb, 3, 5); //ID_PCE
adts->pce_size = (ff_copy_pce_data(&pb, &gb) + 3) / 8;
flush_put_bits(&pb);
}
adts->write_adts = 1;
return 0;
}
static int adts_init(AVFormatContext *s)
{
ADTSContext *adts = s->priv_data;
AVCodecParameters *par = s->streams[0]->codecpar;
if (par->codec_id != AV_CODEC_ID_AAC) {
av_log(s, AV_LOG_ERROR, "Only AAC streams can be muxed by the ADTS muxer\n");
return AVERROR(EINVAL);
}
if (par->extradata_size > 0)
return adts_decode_extradata(s, adts, par->extradata,
par->extradata_size);
return 0;
}
static int adts_write_header(AVFormatContext *s)
{
ADTSContext *adts = s->priv_data;
if (adts->id3v2tag)
ff_id3v2_write_simple(s, 4, ID3v2_DEFAULT_MAGIC);
return 0;
}
static int adts_write_frame_header(ADTSContext *ctx,
uint8_t *buf, int size, int pce_size)
{
PutBitContext pb;
unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size;
if (full_frame_size > ADTS_MAX_FRAME_BYTES) {
av_log(NULL, AV_LOG_ERROR, "ADTS frame size too large: %u (max %d)\n",
full_frame_size, ADTS_MAX_FRAME_BYTES);
return AVERROR_INVALIDDATA;
}
init_put_bits(&pb, buf, ADTS_HEADER_SIZE);
/* adts_fixed_header */
put_bits(&pb, 12, 0xfff); /* syncword */
put_bits(&pb, 1, 0); /* ID */
put_bits(&pb, 2, 0); /* layer */
put_bits(&pb, 1, 1); /* protection_absent */
put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */
put_bits(&pb, 4, ctx->sample_rate_index);
put_bits(&pb, 1, 0); /* private_bit */
put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */
put_bits(&pb, 1, 0); /* original_copy */
put_bits(&pb, 1, 0); /* home */
/* adts_variable_header */
put_bits(&pb, 1, 0); /* copyright_identification_bit */
put_bits(&pb, 1, 0); /* copyright_identification_start */
put_bits(&pb, 13, full_frame_size); /* aac_frame_length */
put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */
put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */
flush_put_bits(&pb);
return 0;
}
static int adts_write_packet(AVFormatContext *s, AVPacket *pkt)
{
ADTSContext *adts = s->priv_data;
AVCodecParameters *par = s->streams[0]->codecpar;
AVIOContext *pb = s->pb;
uint8_t buf[ADTS_HEADER_SIZE];
if (!pkt->size)
return 0;
if (!par->extradata_size) {
uint8_t *side_data;
int side_data_size = 0, ret;
side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
&side_data_size);
if (side_data_size) {
ret = adts_decode_extradata(s, adts, side_data, side_data_size);
if (ret < 0)
return ret;
ret = ff_alloc_extradata(par, side_data_size);
if (ret < 0)
return ret;
memcpy(par->extradata, side_data, side_data_size);
}
}
if (adts->write_adts) {
int err = adts_write_frame_header(adts, buf, pkt->size,
adts->pce_size);
if (err < 0)
return err;
avio_write(pb, buf, ADTS_HEADER_SIZE);
if (adts->pce_size) {
avio_write(pb, adts->pce_data, adts->pce_size);
adts->pce_size = 0;
}
}
avio_write(pb, pkt->data, pkt->size);
return 0;
}
static int adts_write_trailer(AVFormatContext *s)
{
ADTSContext *adts = s->priv_data;
if (adts->apetag)
ff_ape_write_tag(s);
return 0;
}
#define ENC AV_OPT_FLAG_ENCODING_PARAM
#define OFFSET(obj) offsetof(ADTSContext, obj)
static const AVOption options[] = {
{ "write_id3v2", "Enable ID3v2 tag writing", OFFSET(id3v2tag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC},
{ "write_apetag", "Enable APE tag writing", OFFSET(apetag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC},
{ NULL },
};
static const AVClass adts_muxer_class = {
.class_name = "ADTS muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_adts_muxer = {
.name = "adts",
.long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"),
.mime_type = "audio/aac",
.extensions = "aac,adts",
.priv_data_size = sizeof(ADTSContext),
.audio_codec = AV_CODEC_ID_AAC,
.video_codec = AV_CODEC_ID_NONE,
.init = adts_init,
.write_header = adts_write_header,
.write_packet = adts_write_packet,
.write_trailer = adts_write_trailer,
.priv_class = &adts_muxer_class,
.flags = AVFMT_NOTIMESTAMPS,
};
|
