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au.c
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1 /*
2  * AU muxer and demuxer
3  * Copyright (c) 2001 Fabrice Bellard
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  * First version by Francois Revol revol@free.fr
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 /* The libavcodec codecs we support, and the IDs they have in the file */
41 static const AVCodecTag codec_au_tags[] = {
42  { AV_CODEC_ID_PCM_MULAW, 1 },
43  { AV_CODEC_ID_PCM_S8, 2 },
44  { AV_CODEC_ID_PCM_S16BE, 3 },
45  { AV_CODEC_ID_PCM_S24BE, 4 },
46  { AV_CODEC_ID_PCM_S32BE, 5 },
47  { AV_CODEC_ID_PCM_F32BE, 6 },
48  { AV_CODEC_ID_PCM_F64BE, 7 },
49  { AV_CODEC_ID_ADPCM_G722, 24 },
50  { AV_CODEC_ID_PCM_ALAW, 27 },
51  { AV_CODEC_ID_NONE, 0 },
52 };
53 
54 #if CONFIG_AU_DEMUXER
55 
56 static int au_probe(AVProbeData *p)
57 {
58  /* check file header */
59  if (p->buf[0] == '.' && p->buf[1] == 's' &&
60  p->buf[2] == 'n' && p->buf[3] == 'd')
61  return AVPROBE_SCORE_MAX;
62  else
63  return 0;
64 }
65 
66 /* au input */
67 static int au_read_header(AVFormatContext *s)
68 {
69  int size, bps, data_size = 0;
70  unsigned int tag;
71  AVIOContext *pb = s->pb;
72  unsigned int id, channels, rate;
73  enum AVCodecID codec;
74  AVStream *st;
75 
76  /* check ".snd" header */
77  tag = avio_rl32(pb);
78  if (tag != MKTAG('.', 's', 'n', 'd'))
79  return AVERROR_INVALIDDATA;
80  size = avio_rb32(pb); /* header size */
81  data_size = avio_rb32(pb); /* data size in bytes */
82 
83  if (data_size < 0 && data_size != AU_UNKNOWN_SIZE) {
84  av_log(s, AV_LOG_ERROR, "Invalid negative data size '%d' found\n", data_size);
85  return AVERROR_INVALIDDATA;
86  }
87 
88  id = avio_rb32(pb);
89  rate = avio_rb32(pb);
90  channels = avio_rb32(pb);
91 
92  codec = ff_codec_get_id(codec_au_tags, id);
93 
94  if (!(bps = av_get_bits_per_sample(codec))) {
95  av_log_ask_for_sample(s, "could not determine bits per sample\n");
96  return AVERROR_PATCHWELCOME;
97  }
98 
99  if (channels == 0 || channels > 64) {
100  av_log(s, AV_LOG_ERROR, "Invalid number of channels %d\n", channels);
101  return AVERROR_INVALIDDATA;
102  }
103 
104  if (size >= 24) {
105  /* skip unused data */
106  avio_skip(pb, size - 24);
107  }
108 
109  /* now we are ready: build format streams */
110  st = avformat_new_stream(s, NULL);
111  if (!st)
112  return AVERROR(ENOMEM);
114  st->codec->codec_tag = id;
115  st->codec->codec_id = codec;
116  st->codec->channels = channels;
117  st->codec->sample_rate = rate;
118  st->codec->block_align = FFMAX(bps * st->codec->channels / 8, 1);
119  if (data_size != AU_UNKNOWN_SIZE)
120  st->duration = (((int64_t)data_size)<<3) / (st->codec->channels * (int64_t)bps);
121  avpriv_set_pts_info(st, 64, 1, rate);
122  return 0;
123 }
124 
125 AVInputFormat ff_au_demuxer = {
126  .name = "au",
127  .long_name = NULL_IF_CONFIG_SMALL("Sun AU"),
128  .read_probe = au_probe,
129  .read_header = au_read_header,
130  .read_packet = ff_pcm_read_packet,
131  .read_seek = ff_pcm_read_seek,
132  .codec_tag = (const AVCodecTag* const []){ codec_au_tags, 0 },
133 };
134 #endif /* CONFIG_AU_DEMUXER */
135 
136 #if CONFIG_AU_MUXER
137 
138 #include "rawenc.h"
139 
140 /* AUDIO_FILE header */
141 static int put_au_header(AVIOContext *pb, AVCodecContext *enc)
142 {
143  if(!enc->codec_tag)
144  return -1;
145  ffio_wfourcc(pb, ".snd"); /* magic number */
146  avio_wb32(pb, AU_HEADER_SIZE); /* header size */
147  avio_wb32(pb, AU_UNKNOWN_SIZE); /* data size */
148  avio_wb32(pb, (uint32_t)enc->codec_tag); /* codec ID */
149  avio_wb32(pb, enc->sample_rate);
150  avio_wb32(pb, (uint32_t)enc->channels);
151  avio_wb64(pb, 0); /* annotation field */
152  return 0;
153 }
154 
155 static int au_write_header(AVFormatContext *s)
156 {
157  AVIOContext *pb = s->pb;
158 
159  /* format header */
160  if (put_au_header(pb, s->streams[0]->codec) < 0) {
161  return AVERROR(EINVAL);
162  }
163 
164  avio_flush(pb);
165 
166  return 0;
167 }
168 
169 static int au_write_trailer(AVFormatContext *s)
170 {
171  AVIOContext *pb = s->pb;
172  int64_t file_size = avio_tell(pb);
173 
174  if (s->pb->seekable && file_size < INT32_MAX) {
175  /* update file size */
176  avio_seek(pb, 8, SEEK_SET);
177  avio_wb32(pb, (uint32_t)(file_size - AU_HEADER_SIZE));
178  avio_seek(pb, file_size, SEEK_SET);
179 
180  avio_flush(pb);
181  }
182 
183  return 0;
184 }
185 
186 AVOutputFormat ff_au_muxer = {
187  .name = "au",
188  .long_name = NULL_IF_CONFIG_SMALL("Sun AU"),
189  .mime_type = "audio/basic",
190  .extensions = "au",
191  .audio_codec = AV_CODEC_ID_PCM_S16BE,
192  .video_codec = AV_CODEC_ID_NONE,
193  .write_header = au_write_header,
194  .write_packet = ff_raw_write_packet,
195  .write_trailer = au_write_trailer,
196  .codec_tag = (const AVCodecTag* const []){ codec_au_tags, 0 },
197 };
198 #endif /* CONFIG_AU_MUXER */