3 * Copyright (c) 2001 ffmpeg project
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 Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
25 Only mono files are supported.
29 #include "libavutil/channel_layout.h"
34 uint64_t cumulated_size
;
38 static const char AMR_header
[] = "#!AMR\n";
39 static const char AMRWB_header
[] = "#!AMR-WB\n";
42 static int amr_write_header(AVFormatContext
*s
)
44 AVIOContext
*pb
= s
->pb
;
45 AVCodecContext
*enc
= s
->streams
[0]->codec
;
49 if (enc
->codec_id
== AV_CODEC_ID_AMR_NB
) {
50 avio_write(pb
, AMR_header
, sizeof(AMR_header
) - 1); /* magic number */
51 } else if (enc
->codec_id
== AV_CODEC_ID_AMR_WB
) {
52 avio_write(pb
, AMRWB_header
, sizeof(AMRWB_header
) - 1); /* magic number */
60 static int amr_write_packet(AVFormatContext
*s
, AVPacket
*pkt
)
62 avio_write(s
->pb
, pkt
->data
, pkt
->size
);
65 #endif /* CONFIG_AMR_MUXER */
67 static int amr_probe(AVProbeData
*p
)
69 // Only check for "#!AMR" which could be amr-wb, amr-nb.
70 // This will also trigger multichannel files: "#!AMR_MC1.0\n" and
71 // "#!AMR-WB_MC1.0\n" (not supported)
73 if (!memcmp(p
->buf
, AMR_header
, 5))
74 return AVPROBE_SCORE_MAX
;
80 static int amr_read_header(AVFormatContext
*s
)
82 AVIOContext
*pb
= s
->pb
;
86 avio_read(pb
, header
, 6);
88 st
= avformat_new_stream(s
, NULL
);
90 return AVERROR(ENOMEM
);
91 if (memcmp(header
, AMR_header
, 6)) {
92 avio_read(pb
, header
+ 6, 3);
93 if (memcmp(header
, AMRWB_header
, 9)) {
97 st
->codec
->codec_tag
= MKTAG('s', 'a', 'w', 'b');
98 st
->codec
->codec_id
= AV_CODEC_ID_AMR_WB
;
99 st
->codec
->sample_rate
= 16000;
101 st
->codec
->codec_tag
= MKTAG('s', 'a', 'm', 'r');
102 st
->codec
->codec_id
= AV_CODEC_ID_AMR_NB
;
103 st
->codec
->sample_rate
= 8000;
105 st
->codec
->channels
= 1;
106 st
->codec
->channel_layout
= AV_CH_LAYOUT_MONO
;
107 st
->codec
->codec_type
= AVMEDIA_TYPE_AUDIO
;
108 avpriv_set_pts_info(st
, 64, 1, st
->codec
->sample_rate
);
113 static int amr_read_packet(AVFormatContext
*s
, AVPacket
*pkt
)
115 AVCodecContext
*enc
= s
->streams
[0]->codec
;
116 int read
, size
= 0, toc
, mode
;
117 int64_t pos
= avio_tell(s
->pb
);
118 AMRContext
*amr
= s
->priv_data
;
120 if (avio_feof(s
->pb
)) {
124 // FIXME this is wrong, this should rather be in a AVParser
125 toc
= avio_r8(s
->pb
);
126 mode
= (toc
>> 3) & 0x0F;
128 if (enc
->codec_id
== AV_CODEC_ID_AMR_NB
) {
129 static const uint8_t packed_size
[16] = {
130 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0
133 size
= packed_size
[mode
] + 1;
134 } else if (enc
->codec_id
== AV_CODEC_ID_AMR_WB
) {
135 static const uint8_t packed_size
[16] = {
136 18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1
139 size
= packed_size
[mode
];
142 if (!size
|| av_new_packet(pkt
, size
))
145 if (amr
->cumulated_size
< UINT64_MAX
- size
) {
146 amr
->cumulated_size
+= size
;
147 /* Both AMR formats have 50 frames per second */
148 s
->streams
[0]->codec
->bit_rate
= amr
->cumulated_size
/ ++amr
->block_count
* 8 * 50;
151 pkt
->stream_index
= 0;
154 pkt
->duration
= enc
->codec_id
== AV_CODEC_ID_AMR_NB
? 160 : 320;
155 read
= avio_read(s
->pb
, pkt
->data
+ 1, size
- 1);
157 if (read
!= size
- 1) {
165 #if CONFIG_AMR_DEMUXER
166 AVInputFormat ff_amr_demuxer
= {
168 .long_name
= NULL_IF_CONFIG_SMALL("3GPP AMR"),
169 .priv_data_size
= sizeof(AMRContext
),
170 .read_probe
= amr_probe
,
171 .read_header
= amr_read_header
,
172 .read_packet
= amr_read_packet
,
173 .flags
= AVFMT_GENERIC_INDEX
,
178 AVOutputFormat ff_amr_muxer
= {
180 .long_name
= NULL_IF_CONFIG_SMALL("3GPP AMR"),
181 .mime_type
= "audio/amr",
183 .audio_codec
= AV_CODEC_ID_AMR_NB
,
184 .video_codec
= AV_CODEC_ID_NONE
,
185 .write_header
= amr_write_header
,
186 .write_packet
= amr_write_packet
,
187 .flags
= AVFMT_NOTIMESTAMPS
,