Libav
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 Libav.
8  *
9  * Libav 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  * Libav 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 Libav; 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 static const AVCodecTag codec_au_tags[] = {
36  { AV_CODEC_ID_PCM_MULAW, 1 },
37  { AV_CODEC_ID_PCM_S8, 2 },
38  { AV_CODEC_ID_PCM_S16BE, 3 },
39  { AV_CODEC_ID_PCM_S24BE, 4 },
40  { AV_CODEC_ID_PCM_S32BE, 5 },
41  { AV_CODEC_ID_PCM_F32BE, 6 },
42  { AV_CODEC_ID_PCM_F64BE, 7 },
43  { AV_CODEC_ID_PCM_ALAW, 27 },
44  { AV_CODEC_ID_NONE, 0 },
45 };
46 
47 #if CONFIG_AU_DEMUXER
48 
49 static int au_probe(AVProbeData *p)
50 {
51  if (p->buf[0] == '.' && p->buf[1] == 's' &&
52  p->buf[2] == 'n' && p->buf[3] == 'd')
53  return AVPROBE_SCORE_MAX;
54  else
55  return 0;
56 }
57 
58 #define BLOCK_SIZE 1024
59 
60 static int au_read_header(AVFormatContext *s)
61 {
62  int size;
63  unsigned int tag;
64  AVIOContext *pb = s->pb;
65  unsigned int id, channels, rate;
66  int bps;
67  enum AVCodecID codec;
68  AVStream *st;
69 
70  tag = avio_rl32(pb);
71  if (tag != MKTAG('.', 's', 'n', 'd'))
72  return AVERROR_INVALIDDATA;
73  size = avio_rb32(pb); /* header size */
74  avio_rb32(pb); /* data size */
75 
76  id = avio_rb32(pb);
77  rate = avio_rb32(pb);
78  channels = avio_rb32(pb);
79 
80  if (size > 24) {
81  /* skip unused data */
82  avio_skip(pb, size - 24);
83  }
84 
85  codec = ff_codec_get_id(codec_au_tags, id);
86 
87  if (codec == AV_CODEC_ID_NONE) {
88  avpriv_request_sample(s, "unknown or unsupported codec tag: %u", id);
89  return AVERROR_PATCHWELCOME;
90  }
91 
92  bps = av_get_bits_per_sample(codec);
93  if (!bps) {
94  avpriv_request_sample(s, "Unknown bits per sample");
95  return AVERROR_PATCHWELCOME;
96  }
97 
98  if (channels == 0 || channels >= INT_MAX / (BLOCK_SIZE * bps >> 3)) {
99  av_log(s, AV_LOG_ERROR, "Invalid number of channels %u\n", channels);
100  return AVERROR_INVALIDDATA;
101  }
102 
103  if (rate == 0 || rate > INT_MAX) {
104  av_log(s, AV_LOG_ERROR, "Invalid sample rate: %u\n", rate);
105  return AVERROR_INVALIDDATA;
106  }
107 
108  st = avformat_new_stream(s, NULL);
109  if (!st)
110  return AVERROR(ENOMEM);
112  st->codec->codec_tag = id;
113  st->codec->codec_id = codec;
114  st->codec->channels = channels;
115  st->codec->sample_rate = rate;
116  st->codec->bit_rate = channels * rate * bps;
117  st->codec->block_align = channels * bps >> 3;
118 
119  st->start_time = 0;
120  avpriv_set_pts_info(st, 64, 1, rate);
121 
122  return 0;
123 }
124 
125 static int au_read_packet(AVFormatContext *s, AVPacket *pkt)
126 {
127  int ret;
128 
129  ret = av_get_packet(s->pb, pkt, BLOCK_SIZE *
130  s->streams[0]->codec->block_align);
131  if (ret < 0)
132  return ret;
133 
134  pkt->stream_index = 0;
135  pkt->duration = ret / s->streams[0]->codec->block_align;
136 
137  return 0;
138 }
139 
140 AVInputFormat ff_au_demuxer = {
141  .name = "au",
142  .long_name = NULL_IF_CONFIG_SMALL("Sun AU"),
143  .read_probe = au_probe,
144  .read_header = au_read_header,
145  .read_packet = au_read_packet,
146  .read_seek = ff_pcm_read_seek,
147  .codec_tag = (const AVCodecTag* const []) { codec_au_tags, 0 },
148 };
149 
150 #endif /* CONFIG_AU_DEMUXER */
151 
152 #if CONFIG_AU_MUXER
153 
154 #include "rawenc.h"
155 
156 /* if we don't know the size in advance */
157 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
158 
159 /* AUDIO_FILE header */
160 static int put_au_header(AVIOContext *pb, AVCodecContext *enc)
161 {
162  if (!enc->codec_tag)
163  return AVERROR(EINVAL);
164 
165  ffio_wfourcc(pb, ".snd"); /* magic number */
166  avio_wb32(pb, 24); /* header size */
167  avio_wb32(pb, AU_UNKNOWN_SIZE); /* data size */
168  avio_wb32(pb, enc->codec_tag); /* codec ID */
169  avio_wb32(pb, enc->sample_rate);
170  avio_wb32(pb, enc->channels);
171 
172  return 0;
173 }
174 
175 static int au_write_header(AVFormatContext *s)
176 {
177  AVIOContext *pb = s->pb;
178  int ret;
179 
180  s->priv_data = NULL;
181 
182  if ((ret = put_au_header(pb, s->streams[0]->codec)) < 0)
183  return ret;
184 
185  avio_flush(pb);
186 
187  return 0;
188 }
189 
190 static int au_write_trailer(AVFormatContext *s)
191 {
192  AVIOContext *pb = s->pb;
193  int64_t file_size;
194 
195  if (s->pb->seekable) {
196  /* update file size */
197  file_size = avio_tell(pb);
198  avio_seek(pb, 8, SEEK_SET);
199  avio_wb32(pb, (uint32_t)(file_size - 24));
200  avio_seek(pb, file_size, SEEK_SET);
201  avio_flush(pb);
202  }
203 
204  return 0;
205 }
206 
207 AVOutputFormat ff_au_muxer = {
208  .name = "au",
209  .long_name = NULL_IF_CONFIG_SMALL("Sun AU"),
210  .mime_type = "audio/basic",
211  .extensions = "au",
212  .audio_codec = AV_CODEC_ID_PCM_S16BE,
213  .video_codec = AV_CODEC_ID_NONE,
214  .write_header = au_write_header,
215  .write_packet = ff_raw_write_packet,
216  .write_trailer = au_write_trailer,
217  .codec_tag = (const AVCodecTag* const []) { codec_au_tags, 0 },
218 };
219 
220 #endif /* CONFIG_AU_MUXER */