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 /*
23 Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
24
25 Only mono files are supported.
26
27 */
28
29 #include "libavutil/channel_layout.h"
30 #include "avformat.h"
31 #include "internal.h"
32 #include "rawenc.h"
33
34 typedef struct {
35 uint64_t cumulated_size;
36 uint64_t block_count;
37 } AMRContext;
38
39 static const char AMR_header[] = "#!AMR\n";
40 static const char AMRWB_header[] = "#!AMR-WB\n";
41
42 static const uint8_t amrnb_packed_size[16] = {
43 13, 14, 16, 18, 20, 21, 27, 32, 6, 1, 1, 1, 1, 1, 1, 1
44 };
45 static const uint8_t amrwb_packed_size[16] = {
46 18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 1, 1, 1, 1, 1, 1
47 };
48
49 #if CONFIG_AMR_MUXER
amr_write_header(AVFormatContext * s)50 static int amr_write_header(AVFormatContext *s)
51 {
52 AVIOContext *pb = s->pb;
53 AVCodecParameters *par = s->streams[0]->codecpar;
54
55 s->priv_data = NULL;
56
57 if (par->codec_id == AV_CODEC_ID_AMR_NB) {
58 avio_write(pb, AMR_header, sizeof(AMR_header) - 1); /* magic number */
59 } else if (par->codec_id == AV_CODEC_ID_AMR_WB) {
60 avio_write(pb, AMRWB_header, sizeof(AMRWB_header) - 1); /* magic number */
61 } else {
62 return -1;
63 }
64 return 0;
65 }
66 #endif /* CONFIG_AMR_MUXER */
67
amr_probe(const AVProbeData * p)68 static int amr_probe(const AVProbeData *p)
69 {
70 // Only check for "#!AMR" which could be amr-wb, amr-nb.
71 // This will also trigger multichannel files: "#!AMR_MC1.0\n" and
72 // "#!AMR-WB_MC1.0\n" (not supported)
73
74 if (!memcmp(p->buf, AMR_header, 5))
75 return AVPROBE_SCORE_MAX;
76 else
77 return 0;
78 }
79
80 /* amr input */
amr_read_header(AVFormatContext * s)81 static int amr_read_header(AVFormatContext *s)
82 {
83 AVIOContext *pb = s->pb;
84 AVStream *st;
85 uint8_t header[9];
86
87 if (avio_read(pb, header, 6) != 6)
88 return AVERROR_INVALIDDATA;
89
90 st = avformat_new_stream(s, NULL);
91 if (!st)
92 return AVERROR(ENOMEM);
93 if (memcmp(header, AMR_header, 6)) {
94 if (avio_read(pb, header + 6, 3) != 3)
95 return AVERROR_INVALIDDATA;
96 if (memcmp(header, AMRWB_header, 9)) {
97 return -1;
98 }
99
100 st->codecpar->codec_tag = MKTAG('s', 'a', 'w', 'b');
101 st->codecpar->codec_id = AV_CODEC_ID_AMR_WB;
102 st->codecpar->sample_rate = 16000;
103 } else {
104 st->codecpar->codec_tag = MKTAG('s', 'a', 'm', 'r');
105 st->codecpar->codec_id = AV_CODEC_ID_AMR_NB;
106 st->codecpar->sample_rate = 8000;
107 }
108 st->codecpar->channels = 1;
109 st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
110 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
111 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
112
113 return 0;
114 }
115
amr_read_packet(AVFormatContext * s,AVPacket * pkt)116 static int amr_read_packet(AVFormatContext *s, AVPacket *pkt)
117 {
118 AVCodecParameters *par = s->streams[0]->codecpar;
119 int read, size = 0, toc, mode;
120 int64_t pos = avio_tell(s->pb);
121 AMRContext *amr = s->priv_data;
122
123 if (avio_feof(s->pb)) {
124 return AVERROR_EOF;
125 }
126
127 // FIXME this is wrong, this should rather be in an AVParser
128 toc = avio_r8(s->pb);
129 mode = (toc >> 3) & 0x0F;
130
131 if (par->codec_id == AV_CODEC_ID_AMR_NB) {
132 size = amrnb_packed_size[mode];
133 } else if (par->codec_id == AV_CODEC_ID_AMR_WB) {
134 size = amrwb_packed_size[mode];
135 }
136
137 if (!size || av_new_packet(pkt, size))
138 return AVERROR(EIO);
139
140 if (amr->cumulated_size < UINT64_MAX - size) {
141 amr->cumulated_size += size;
142 /* Both AMR formats have 50 frames per second */
143 s->streams[0]->codecpar->bit_rate = amr->cumulated_size / ++amr->block_count * 8 * 50;
144 }
145
146 pkt->stream_index = 0;
147 pkt->pos = pos;
148 pkt->data[0] = toc;
149 pkt->duration = par->codec_id == AV_CODEC_ID_AMR_NB ? 160 : 320;
150 read = avio_read(s->pb, pkt->data + 1, size - 1);
151
152 if (read != size - 1) {
153 if (read < 0)
154 return read;
155 return AVERROR(EIO);
156 }
157
158 return 0;
159 }
160
161 #if CONFIG_AMR_DEMUXER
162 AVInputFormat ff_amr_demuxer = {
163 .name = "amr",
164 .long_name = NULL_IF_CONFIG_SMALL("3GPP AMR"),
165 .priv_data_size = sizeof(AMRContext),
166 .read_probe = amr_probe,
167 .read_header = amr_read_header,
168 .read_packet = amr_read_packet,
169 .flags = AVFMT_GENERIC_INDEX,
170 };
171 #endif
172
173 #if CONFIG_AMRNB_DEMUXER
amrnb_probe(const AVProbeData * p)174 static int amrnb_probe(const AVProbeData *p)
175 {
176 int mode, i = 0, valid = 0, invalid = 0;
177 const uint8_t *b = p->buf;
178
179 while (i < p->buf_size) {
180 mode = b[i] >> 3 & 0x0F;
181 if (mode < 9 && (b[i] & 0x4) == 0x4) {
182 int last = b[i];
183 int size = amrnb_packed_size[mode];
184 while (size--) {
185 if (b[++i] != last)
186 break;
187 }
188 if (size > 0) {
189 valid++;
190 i += size;
191 }
192 } else {
193 valid = 0;
194 invalid++;
195 i++;
196 }
197 }
198 if (valid > 100 && valid >> 4 > invalid)
199 return AVPROBE_SCORE_EXTENSION / 2 + 1;
200 return 0;
201 }
202
amrnb_read_header(AVFormatContext * s)203 static int amrnb_read_header(AVFormatContext *s)
204 {
205 AVStream *st = avformat_new_stream(s, NULL);
206 if (!st)
207 return AVERROR(ENOMEM);
208 st->codecpar->codec_id = AV_CODEC_ID_AMR_NB;
209 st->codecpar->sample_rate = 8000;
210 st->codecpar->channels = 1;
211 st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
212 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
213 avpriv_set_pts_info(st, 64, 1, 8000);
214
215 return 0;
216 }
217
218 AVInputFormat ff_amrnb_demuxer = {
219 .name = "amrnb",
220 .long_name = NULL_IF_CONFIG_SMALL("raw AMR-NB"),
221 .priv_data_size = sizeof(AMRContext),
222 .read_probe = amrnb_probe,
223 .read_header = amrnb_read_header,
224 .read_packet = amr_read_packet,
225 .flags = AVFMT_GENERIC_INDEX,
226 };
227 #endif
228
229 #if CONFIG_AMRWB_DEMUXER
amrwb_probe(const AVProbeData * p)230 static int amrwb_probe(const AVProbeData *p)
231 {
232 int mode, i = 0, valid = 0, invalid = 0;
233 const uint8_t *b = p->buf;
234
235 while (i < p->buf_size) {
236 mode = b[i] >> 3 & 0x0F;
237 if (mode < 10 && (b[i] & 0x4) == 0x4) {
238 int last = b[i];
239 int size = amrwb_packed_size[mode];
240 while (size--) {
241 if (b[++i] != last)
242 break;
243 }
244 if (size > 0) {
245 valid++;
246 i += size;
247 }
248 } else {
249 valid = 0;
250 invalid++;
251 i++;
252 }
253 }
254 if (valid > 100 && valid >> 4 > invalid)
255 return AVPROBE_SCORE_EXTENSION / 2 + 1;
256 return 0;
257 }
258
amrwb_read_header(AVFormatContext * s)259 static int amrwb_read_header(AVFormatContext *s)
260 {
261 AVStream *st = avformat_new_stream(s, NULL);
262 if (!st)
263 return AVERROR(ENOMEM);
264 st->codecpar->codec_id = AV_CODEC_ID_AMR_WB;
265 st->codecpar->sample_rate = 16000;
266 st->codecpar->channels = 1;
267 st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
268 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
269 avpriv_set_pts_info(st, 64, 1, 16000);
270
271 return 0;
272 }
273
274 AVInputFormat ff_amrwb_demuxer = {
275 .name = "amrwb",
276 .long_name = NULL_IF_CONFIG_SMALL("raw AMR-WB"),
277 .priv_data_size = sizeof(AMRContext),
278 .read_probe = amrwb_probe,
279 .read_header = amrwb_read_header,
280 .read_packet = amr_read_packet,
281 .flags = AVFMT_GENERIC_INDEX,
282 };
283 #endif
284
285 #if CONFIG_AMR_MUXER
286 AVOutputFormat ff_amr_muxer = {
287 .name = "amr",
288 .long_name = NULL_IF_CONFIG_SMALL("3GPP AMR"),
289 .mime_type = "audio/amr",
290 .extensions = "amr",
291 .audio_codec = AV_CODEC_ID_AMR_NB,
292 .video_codec = AV_CODEC_ID_NONE,
293 .write_header = amr_write_header,
294 .write_packet = ff_raw_write_packet,
295 .flags = AVFMT_NOTIMESTAMPS,
296 };
297 #endif
298