1/*
2 * amr file format
3 * Copyright (c) 2001 ffmpeg project
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/*
23Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
24
25Only mono files are supported.
26
27*/
28#include "avformat.h"
29
30static const char AMR_header [] = "#!AMR\n";
31static const char AMRWB_header [] = "#!AMR-WB\n";
32
33#if CONFIG_AMR_MUXER
34static int amr_write_header(AVFormatContext *s)
35{
36    ByteIOContext *pb = s->pb;
37    AVCodecContext *enc = s->streams[0]->codec;
38
39    s->priv_data = NULL;
40
41    if (enc->codec_id == CODEC_ID_AMR_NB)
42    {
43        put_tag(pb, AMR_header);       /* magic number */
44    }
45    else if(enc->codec_id == CODEC_ID_AMR_WB)
46    {
47        put_tag(pb, AMRWB_header);       /* magic number */
48    }
49    else
50    {
51        return -1;
52    }
53    put_flush_packet(pb);
54    return 0;
55}
56
57static int amr_write_packet(AVFormatContext *s, AVPacket *pkt)
58{
59    put_buffer(s->pb, pkt->data, pkt->size);
60    put_flush_packet(s->pb);
61    return 0;
62}
63#endif /* CONFIG_AMR_MUXER */
64
65static int amr_probe(AVProbeData *p)
66{
67    //Only check for "#!AMR" which could be amr-wb, amr-nb.
68    //This will also trigger multichannel files: "#!AMR_MC1.0\n" and
69    //"#!AMR-WB_MC1.0\n" (not supported)
70
71    if(memcmp(p->buf,AMR_header,5)==0)
72        return AVPROBE_SCORE_MAX;
73    else
74        return 0;
75}
76
77/* amr input */
78static int amr_read_header(AVFormatContext *s,
79                           AVFormatParameters *ap)
80{
81    ByteIOContext *pb = s->pb;
82    AVStream *st;
83    uint8_t header[9];
84
85    get_buffer(pb, header, 6);
86
87    st = av_new_stream(s, 0);
88    if (!st)
89    {
90        return AVERROR(ENOMEM);
91    }
92    if(memcmp(header,AMR_header,6)!=0)
93    {
94        get_buffer(pb, header+6, 3);
95        if(memcmp(header,AMRWB_header,9)!=0)
96        {
97            return -1;
98        }
99
100        st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b');
101        st->codec->codec_id = CODEC_ID_AMR_WB;
102        st->codec->sample_rate = 16000;
103    }
104    else
105    {
106        st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r');
107        st->codec->codec_id = CODEC_ID_AMR_NB;
108        st->codec->sample_rate = 8000;
109    }
110    st->codec->channels = 1;
111    st->codec->codec_type = CODEC_TYPE_AUDIO;
112    av_set_pts_info(st, 64, 1, st->codec->sample_rate);
113
114    return 0;
115}
116
117static int amr_read_packet(AVFormatContext *s,
118                          AVPacket *pkt)
119{
120    AVCodecContext *enc = s->streams[0]->codec;
121    int read, size = 0, toc, mode;
122
123    if (url_feof(s->pb))
124    {
125        return AVERROR(EIO);
126    }
127
128//FIXME this is wrong, this should rather be in a AVParset
129    toc=get_byte(s->pb);
130    mode = (toc >> 3) & 0x0F;
131
132    if (enc->codec_id == CODEC_ID_AMR_NB)
133    {
134        static const uint8_t packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};
135
136        size=packed_size[mode]+1;
137    }
138    else if(enc->codec_id == CODEC_ID_AMR_WB)
139    {
140        static uint8_t packed_size[16] = {18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1};
141
142        size=packed_size[mode];
143    }
144    else
145    {
146        assert(0);
147    }
148
149    if ( (size==0) || av_new_packet(pkt, size))
150    {
151        return AVERROR(EIO);
152    }
153
154    pkt->stream_index = 0;
155    pkt->pos= url_ftell(s->pb);
156    pkt->data[0]=toc;
157    pkt->duration= enc->codec_id == CODEC_ID_AMR_NB ? 160 : 320;
158    read = get_buffer(s->pb, pkt->data+1, size-1);
159
160    if (read != size-1)
161    {
162        av_free_packet(pkt);
163        return AVERROR(EIO);
164    }
165
166    return 0;
167}
168
169#if CONFIG_AMR_DEMUXER
170AVInputFormat amr_demuxer = {
171    "amr",
172    NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
173    0, /*priv_data_size*/
174    amr_probe,
175    amr_read_header,
176    amr_read_packet,
177    NULL,
178};
179#endif
180
181#if CONFIG_AMR_MUXER
182AVOutputFormat amr_muxer = {
183    "amr",
184    NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
185    "audio/amr",
186    "amr",
187    0,
188    CODEC_ID_AMR_NB,
189    CODEC_ID_NONE,
190    amr_write_header,
191    amr_write_packet,
192};
193#endif
194