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au.c
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1 /*
2  * AU muxer and demuxer
3  * Copyright (c) 2001 Fabrice Bellard
4  *
5  * first version by Francois Revol <revol@free.fr>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 /*
25  * Reference documents:
26  * http://www.opengroup.org/public/pubs/external/auformat.html
27  * http://www.goice.co.jp/member/mo/formats/au.html
28  */
29 
30 #include "avformat.h"
31 #include "internal.h"
32 #include "avio_internal.h"
33 #include "pcm.h"
34 
35 /* if we don't know the size in advance */
36 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
37 /* the specification requires an annotation field of at least eight bytes */
38 #define AU_HEADER_SIZE (24+8)
39 
40 static const AVCodecTag codec_au_tags[] = {
41  { AV_CODEC_ID_PCM_MULAW, 1 },
42  { AV_CODEC_ID_PCM_S8, 2 },
43  { AV_CODEC_ID_PCM_S16BE, 3 },
44  { AV_CODEC_ID_PCM_S24BE, 4 },
45  { AV_CODEC_ID_PCM_S32BE, 5 },
46  { AV_CODEC_ID_PCM_F32BE, 6 },
47  { AV_CODEC_ID_PCM_F64BE, 7 },
49  { AV_CODEC_ID_PCM_ALAW, 27 },
50  { AV_CODEC_ID_NONE, 0 },
51 };
52 
53 #if CONFIG_AU_DEMUXER
54 
55 static int au_probe(AVProbeData *p)
56 {
57  if (p->buf[0] == '.' && p->buf[1] == 's' &&
58  p->buf[2] == 'n' && p->buf[3] == 'd')
59  return AVPROBE_SCORE_MAX;
60  else
61  return 0;
62 }
63 
64 #define BLOCK_SIZE 1024
65 
66 static int au_read_header(AVFormatContext *s)
67 {
68  int size, data_size = 0;
69  unsigned int tag;
70  AVIOContext *pb = s->pb;
71  unsigned int id, channels, rate;
72  int bps;
73  enum AVCodecID codec;
74  AVStream *st;
75 
76  tag = avio_rl32(pb);
77  if (tag != MKTAG('.', 's', 'n', 'd'))
78  return AVERROR_INVALIDDATA;
79  size = avio_rb32(pb); /* header size */
80  data_size = avio_rb32(pb); /* data size in bytes */
81 
82  if (data_size < 0 && data_size != AU_UNKNOWN_SIZE) {
83  av_log(s, AV_LOG_ERROR, "Invalid negative data size '%d' found\n", data_size);
84  return AVERROR_INVALIDDATA;
85  }
86 
87  id = avio_rb32(pb);
88  rate = avio_rb32(pb);
89  channels = avio_rb32(pb);
90 
91  if (size > 24) {
92  /* skip unused data */
93  avio_skip(pb, size - 24);
94  }
95 
96  codec = ff_codec_get_id(codec_au_tags, id);
97 
98  if (codec == AV_CODEC_ID_NONE) {
99  avpriv_request_sample(s, "unknown or unsupported codec tag: %u", id);
100  return AVERROR_PATCHWELCOME;
101  }
102 
103  bps = av_get_bits_per_sample(codec);
104  if (!bps) {
105  avpriv_request_sample(s, "Unknown bits per sample");
106  return AVERROR_PATCHWELCOME;
107  }
108 
109  if (channels == 0 || channels >= INT_MAX / (BLOCK_SIZE * bps >> 3)) {
110  av_log(s, AV_LOG_ERROR, "Invalid number of channels %u\n", channels);
111  return AVERROR_INVALIDDATA;
112  }
113 
114  if (rate == 0 || rate > INT_MAX) {
115  av_log(s, AV_LOG_ERROR, "Invalid sample rate: %u\n", rate);
116  return AVERROR_INVALIDDATA;
117  }
118 
119  st = avformat_new_stream(s, NULL);
120  if (!st)
121  return AVERROR(ENOMEM);
123  st->codec->codec_tag = id;
124  st->codec->codec_id = codec;
125  st->codec->channels = channels;
126  st->codec->sample_rate = rate;
127  st->codec->bit_rate = channels * rate * bps;
128  st->codec->block_align = FFMAX(bps * st->codec->channels / 8, 1);
129  if (data_size != AU_UNKNOWN_SIZE)
130  st->duration = (((int64_t)data_size)<<3) / (st->codec->channels * (int64_t)bps);
131 
132  st->start_time = 0;
133  avpriv_set_pts_info(st, 64, 1, rate);
134 
135  return 0;
136 }
137 
138 AVInputFormat ff_au_demuxer = {
139  .name = "au",
140  .long_name = NULL_IF_CONFIG_SMALL("Sun AU"),
141  .read_probe = au_probe,
142  .read_header = au_read_header,
143  .read_packet = ff_pcm_read_packet,
144  .read_seek = ff_pcm_read_seek,
145  .codec_tag = (const AVCodecTag* const []) { codec_au_tags, 0 },
146 };
147 
148 #endif /* CONFIG_AU_DEMUXER */
149 
150 #if CONFIG_AU_MUXER
151 
152 #include "rawenc.h"
153 
154 static int au_write_header(AVFormatContext *s)
155 {
156  AVIOContext *pb = s->pb;
157  AVCodecContext *enc = s->streams[0]->codec;
158 
159  if (s->nb_streams != 1) {
160  av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
161  return AVERROR(EINVAL);
162  }
163 
164  enc->codec_tag = ff_codec_get_tag(codec_au_tags, enc->codec_id);
165  if (!enc->codec_tag) {
166  av_log(s, AV_LOG_ERROR, "unsupported codec\n");
167  return AVERROR(EINVAL);
168  }
169 
170  ffio_wfourcc(pb, ".snd"); /* magic number */
171  avio_wb32(pb, AU_HEADER_SIZE); /* header size */
172  avio_wb32(pb, AU_UNKNOWN_SIZE); /* data size */
173  avio_wb32(pb, enc->codec_tag); /* codec ID */
174  avio_wb32(pb, enc->sample_rate);
175  avio_wb32(pb, enc->channels);
176  avio_wb64(pb, 0); /* annotation field */
177  avio_flush(pb);
178 
179  return 0;
180 }
181 
182 static int au_write_trailer(AVFormatContext *s)
183 {
184  AVIOContext *pb = s->pb;
185  int64_t file_size = avio_tell(pb);
186 
187  if (s->pb->seekable && file_size < INT32_MAX) {
188  /* update file size */
189  avio_seek(pb, 8, SEEK_SET);
190  avio_wb32(pb, (uint32_t)(file_size - AU_HEADER_SIZE));
191  avio_seek(pb, file_size, SEEK_SET);
192  avio_flush(pb);
193  }
194 
195  return 0;
196 }
197 
198 AVOutputFormat ff_au_muxer = {
199  .name = "au",
200  .long_name = NULL_IF_CONFIG_SMALL("Sun AU"),
201  .mime_type = "audio/basic",
202  .extensions = "au",
203  .audio_codec = AV_CODEC_ID_PCM_S16BE,
204  .video_codec = AV_CODEC_ID_NONE,
205  .write_header = au_write_header,
206  .write_packet = ff_raw_write_packet,
207  .write_trailer = au_write_trailer,
208  .codec_tag = (const AVCodecTag* const []) { codec_au_tags, 0 },
209 };
210 
211 #endif /* CONFIG_AU_MUXER */