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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 #include "riff.h"
35 
36 /* if we don't know the size in advance */
37 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
38 
39 /* The libavcodec codecs we support, and the IDs they have in the file */
40 static const AVCodecTag codec_au_tags[] = {
41  { CODEC_ID_PCM_MULAW, 1 },
42  { CODEC_ID_PCM_S8, 2 },
43  { CODEC_ID_PCM_S16BE, 3 },
44  { CODEC_ID_PCM_S24BE, 4 },
45  { CODEC_ID_PCM_S32BE, 5 },
46  { CODEC_ID_PCM_F32BE, 6 },
47  { CODEC_ID_PCM_F64BE, 7 },
48  { CODEC_ID_PCM_ALAW, 27 },
49  { CODEC_ID_NONE, 0 },
50 };
51 
52 #if CONFIG_AU_MUXER
53 /* AUDIO_FILE header */
54 static int put_au_header(AVIOContext *pb, AVCodecContext *enc)
55 {
56  if(!enc->codec_tag)
57  return -1;
58  ffio_wfourcc(pb, ".snd"); /* magic number */
59  avio_wb32(pb, 24); /* header size */
60  avio_wb32(pb, AU_UNKNOWN_SIZE); /* data size */
61  avio_wb32(pb, (uint32_t)enc->codec_tag); /* codec ID */
62  avio_wb32(pb, enc->sample_rate);
63  avio_wb32(pb, (uint32_t)enc->channels);
64  return 0;
65 }
66 
67 static int au_write_header(AVFormatContext *s)
68 {
69  AVIOContext *pb = s->pb;
70 
71  s->priv_data = NULL;
72 
73  /* format header */
74  if (put_au_header(pb, s->streams[0]->codec) < 0) {
75  return -1;
76  }
77 
78  avio_flush(pb);
79 
80  return 0;
81 }
82 
83 static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
84 {
85  AVIOContext *pb = s->pb;
86  avio_write(pb, pkt->data, pkt->size);
87  return 0;
88 }
89 
90 static int au_write_trailer(AVFormatContext *s)
91 {
92  AVIOContext *pb = s->pb;
93  int64_t file_size;
94 
95  if (s->pb->seekable) {
96 
97  /* update file size */
98  file_size = avio_tell(pb);
99  avio_seek(pb, 8, SEEK_SET);
100  avio_wb32(pb, (uint32_t)(file_size - 24));
101  avio_seek(pb, file_size, SEEK_SET);
102 
103  avio_flush(pb);
104  }
105 
106  return 0;
107 }
108 #endif /* CONFIG_AU_MUXER */
109 
110 static int au_probe(AVProbeData *p)
111 {
112  /* check file header */
113  if (p->buf[0] == '.' && p->buf[1] == 's' &&
114  p->buf[2] == 'n' && p->buf[3] == 'd')
115  return AVPROBE_SCORE_MAX;
116  else
117  return 0;
118 }
119 
120 /* au input */
122  AVFormatParameters *ap)
123 {
124  int size;
125  unsigned int tag;
126  AVIOContext *pb = s->pb;
127  unsigned int id, channels, rate;
128  enum CodecID codec;
129  AVStream *st;
130 
131  /* check ".snd" header */
132  tag = avio_rl32(pb);
133  if (tag != MKTAG('.', 's', 'n', 'd'))
134  return -1;
135  size = avio_rb32(pb); /* header size */
136  avio_rb32(pb); /* data size */
137 
138  id = avio_rb32(pb);
139  rate = avio_rb32(pb);
140  channels = avio_rb32(pb);
141 
142  codec = ff_codec_get_id(codec_au_tags, id);
143 
144  if (!av_get_bits_per_sample(codec)) {
145  av_log_ask_for_sample(s, "could not determine bits per sample\n");
146  return AVERROR_INVALIDDATA;
147  }
148 
149  if (size >= 24) {
150  /* skip unused data */
151  avio_skip(pb, size - 24);
152  }
153 
154  /* now we are ready: build format streams */
155  st = avformat_new_stream(s, NULL);
156  if (!st)
157  return -1;
159  st->codec->codec_tag = id;
160  st->codec->codec_id = codec;
161  st->codec->channels = channels;
162  st->codec->sample_rate = rate;
163  avpriv_set_pts_info(st, 64, 1, rate);
164  return 0;
165 }
166 
167 #define BLOCK_SIZE 1024
168 
170  AVPacket *pkt)
171 {
172  int ret;
173 
174  ret= av_get_packet(s->pb, pkt, BLOCK_SIZE *
175  s->streams[0]->codec->channels *
177  if (ret < 0)
178  return ret;
179  pkt->stream_index = 0;
180 
181  /* note: we need to modify the packet size here to handle the last
182  packet */
183  pkt->size = ret;
184  return 0;
185 }
186 
187 #if CONFIG_AU_DEMUXER
188 AVInputFormat ff_au_demuxer = {
189  .name = "au",
190  .long_name = NULL_IF_CONFIG_SMALL("SUN AU format"),
191  .read_probe = au_probe,
192  .read_header = au_read_header,
193  .read_packet = au_read_packet,
194  .read_seek = pcm_read_seek,
195  .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
196 };
197 #endif
198 
199 #if CONFIG_AU_MUXER
200 AVOutputFormat ff_au_muxer = {
201  .name = "au",
202  .long_name = NULL_IF_CONFIG_SMALL("SUN AU format"),
203  .mime_type = "audio/basic",
204  .extensions = "au",
205  .audio_codec = CODEC_ID_PCM_S16BE,
206  .video_codec = CODEC_ID_NONE,
207  .write_header = au_write_header,
208  .write_packet = au_write_packet,
209  .write_trailer = au_write_trailer,
210  .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
211 };
212 #endif //CONFIG_AU_MUXER