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
|
/*
* raw ADTS AAC demuxer
* Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
* Copyright (c) 2009 Robert Swain ( rob opendot cl )
*
* 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "id3v1.h"
#include "id3v2.h"
#include "apetag.h"
#define ADTS_HEADER_SIZE 7
static int adts_aac_probe(const AVProbeData *p)
{
int max_frames = 0, first_frames = 0;
int fsize, frames;
const uint8_t *buf0 = p->buf;
const uint8_t *buf2;
const uint8_t *buf;
const uint8_t *end = buf0 + p->buf_size - 7;
buf = buf0;
for (; buf < end; buf = buf2 + 1) {
buf2 = buf;
for (frames = 0; buf2 < end; frames++) {
uint32_t header = AV_RB16(buf2);
if ((header & 0xFFF6) != 0xFFF0) {
if (buf != buf0) {
// Found something that isn't an ADTS header, starting
// from a position other than the start of the buffer.
// Discard the count we've accumulated so far since it
// probably was a false positive.
frames = 0;
}
break;
}
fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
if (fsize < 7)
break;
fsize = FFMIN(fsize, end - buf2);
buf2 += fsize;
}
max_frames = FFMAX(max_frames, frames);
if (buf == buf0)
first_frames = frames;
}
if (first_frames >= 3)
return AVPROBE_SCORE_EXTENSION + 1;
else if (max_frames > 100)
return AVPROBE_SCORE_EXTENSION;
else if (max_frames >= 3)
return AVPROBE_SCORE_EXTENSION / 2;
else if (first_frames >= 1)
return 1;
else
return 0;
}
static int adts_aac_read_header(AVFormatContext *s)
{
AVStream *st;
uint16_t state;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = s->iformat->raw_codec_id;
st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
ff_id3v1_read(s);
if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
int64_t cur = avio_tell(s->pb);
ff_ape_parse_tag(s);
avio_seek(s->pb, cur, SEEK_SET);
}
// skip data until the first ADTS frame is found
state = avio_r8(s->pb);
while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
state = (state << 8) | avio_r8(s->pb);
if ((state >> 4) != 0xFFF)
continue;
avio_seek(s->pb, -2, SEEK_CUR);
break;
}
if ((state >> 4) != 0xFFF)
return AVERROR_INVALIDDATA;
// LCM of all possible ADTS sample rates
avpriv_set_pts_info(st, 64, 1, 28224000);
return 0;
}
static int handle_id3(AVFormatContext *s, AVPacket *pkt)
{
AVDictionary *metadata = NULL;
AVIOContext ioctx;
ID3v2ExtraMeta *id3v2_extra_meta = NULL;
int ret;
ret = av_append_packet(s->pb, pkt, ff_id3v2_tag_len(pkt->data) - pkt->size);
if (ret < 0) {
av_packet_unref(pkt);
return ret;
}
ffio_init_context(&ioctx, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL);
ff_id3v2_read_dict(&ioctx, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
if ((ret = ff_id3v2_parse_priv_dict(&metadata, &id3v2_extra_meta)) < 0)
goto error;
if (metadata) {
if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0)
goto error;
s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
}
error:
av_packet_unref(pkt);
ff_id3v2_free_extra_meta(&id3v2_extra_meta);
av_dict_free(&metadata);
return ret;
}
static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret, fsize;
// Parse all the ID3 headers between frames
while (1) {
ret = av_get_packet(s->pb, pkt, FFMAX(ID3v2_HEADER_SIZE, ADTS_HEADER_SIZE));
if (ret >= ID3v2_HEADER_SIZE && ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) {
if ((ret = handle_id3(s, pkt)) >= 0) {
continue;
}
}
break;
}
if (ret < 0)
return ret;
if (ret < ADTS_HEADER_SIZE) {
av_packet_unref(pkt);
return AVERROR(EIO);
}
if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
av_packet_unref(pkt);
return AVERROR_INVALIDDATA;
}
fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
if (fsize < ADTS_HEADER_SIZE) {
av_packet_unref(pkt);
return AVERROR_INVALIDDATA;
}
ret = av_append_packet(s->pb, pkt, fsize - pkt->size);
if (ret < 0)
av_packet_unref(pkt);
return ret;
}
AVInputFormat ff_aac_demuxer = {
.name = "aac",
.long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
.read_probe = adts_aac_probe,
.read_header = adts_aac_read_header,
.read_packet = adts_aac_read_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "aac",
.mime_type = "audio/aac,audio/aacp,audio/x-aac",
.raw_codec_id = AV_CODEC_ID_AAC,
};
|
