seek support for PCM formats
[libav.git] / libavformat / au.c
1 /*
2 * AU encoder and decoder
3 * Copyright (c) 2001 Fabrice Bellard.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 /*
21 * First version by Francois Revol revol@free.fr
22 *
23 * Reference documents:
24 * http://www.opengroup.org/public/pubs/external/auformat.html
25 * http://www.goice.co.jp/member/mo/formats/au.html
26 */
27
28 #include "avformat.h"
29 #include "avi.h"
30
31 /* if we don't know the size in advance */
32 #define AU_UNKOWN_SIZE ((uint32_t)(~0))
33
34 /* The ffmpeg codecs we support, and the IDs they have in the file */
35 static const CodecTag codec_au_tags[] = {
36 { CODEC_ID_PCM_MULAW, 1 },
37 { CODEC_ID_PCM_S16BE, 3 },
38 { CODEC_ID_PCM_ALAW, 27 },
39 { 0, 0 },
40 };
41
42 #ifdef CONFIG_ENCODERS
43 /* AUDIO_FILE header */
44 static int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
45 {
46 if(!enc->codec_tag)
47 enc->codec_tag = codec_get_tag(codec_au_tags, enc->codec_id);
48 if(!enc->codec_tag)
49 return -1;
50 put_tag(pb, ".snd"); /* magic number */
51 put_be32(pb, 24); /* header size */
52 put_be32(pb, AU_UNKOWN_SIZE); /* data size */
53 put_be32(pb, (uint32_t)enc->codec_tag); /* codec ID */
54 put_be32(pb, enc->sample_rate);
55 put_be32(pb, (uint32_t)enc->channels);
56 return 0;
57 }
58
59 static int au_write_header(AVFormatContext *s)
60 {
61 ByteIOContext *pb = &s->pb;
62
63 s->priv_data = NULL;
64
65 /* format header */
66 if (put_au_header(pb, &s->streams[0]->codec) < 0) {
67 return -1;
68 }
69
70 put_flush_packet(pb);
71
72 return 0;
73 }
74
75 static int au_write_packet(AVFormatContext *s, int stream_index_ptr,
76 const uint8_t *buf, int size, int64_t pts)
77 {
78 ByteIOContext *pb = &s->pb;
79 put_buffer(pb, buf, size);
80 return 0;
81 }
82
83 static int au_write_trailer(AVFormatContext *s)
84 {
85 ByteIOContext *pb = &s->pb;
86 offset_t file_size;
87
88 if (!url_is_streamed(&s->pb)) {
89
90 /* update file size */
91 file_size = url_ftell(pb);
92 url_fseek(pb, 8, SEEK_SET);
93 put_be32(pb, (uint32_t)(file_size - 24));
94 url_fseek(pb, file_size, SEEK_SET);
95
96 put_flush_packet(pb);
97 }
98
99 return 0;
100 }
101 #endif //CONFIG_ENCODERS
102
103 static int au_probe(AVProbeData *p)
104 {
105 /* check file header */
106 if (p->buf_size <= 24)
107 return 0;
108 if (p->buf[0] == '.' && p->buf[1] == 's' &&
109 p->buf[2] == 'n' && p->buf[3] == 'd')
110 return AVPROBE_SCORE_MAX;
111 else
112 return 0;
113 }
114
115 /* au input */
116 static int au_read_header(AVFormatContext *s,
117 AVFormatParameters *ap)
118 {
119 int size;
120 unsigned int tag;
121 ByteIOContext *pb = &s->pb;
122 unsigned int id, codec, channels, rate;
123 AVStream *st;
124
125 /* check ".snd" header */
126 tag = get_le32(pb);
127 if (tag != MKTAG('.', 's', 'n', 'd'))
128 return -1;
129 size = get_be32(pb); /* header size */
130 get_be32(pb); /* data size */
131
132 id = get_be32(pb);
133 rate = get_be32(pb);
134 channels = get_be32(pb);
135
136 codec = codec_get_id(codec_au_tags, id);
137
138 if (size >= 24) {
139 /* skip unused data */
140 url_fseek(pb, size - 24, SEEK_CUR);
141 }
142
143 /* now we are ready: build format streams */
144 st = av_new_stream(s, 0);
145 if (!st)
146 return -1;
147 st->codec.codec_type = CODEC_TYPE_AUDIO;
148 st->codec.codec_tag = id;
149 st->codec.codec_id = codec;
150 st->codec.channels = channels;
151 st->codec.sample_rate = rate;
152 return 0;
153 }
154
155 #define MAX_SIZE 4096
156
157 static int au_read_packet(AVFormatContext *s,
158 AVPacket *pkt)
159 {
160 int ret;
161
162 if (url_feof(&s->pb))
163 return -EIO;
164 if (av_new_packet(pkt, MAX_SIZE))
165 return -EIO;
166 pkt->stream_index = 0;
167
168 ret = get_buffer(&s->pb, pkt->data, pkt->size);
169 if (ret < 0)
170 av_free_packet(pkt);
171 /* note: we need to modify the packet size here to handle the last
172 packet */
173 pkt->size = ret;
174 return 0;
175 }
176
177 static int au_read_close(AVFormatContext *s)
178 {
179 return 0;
180 }
181
182 static AVInputFormat au_iformat = {
183 "au",
184 "SUN AU Format",
185 0,
186 au_probe,
187 au_read_header,
188 au_read_packet,
189 au_read_close,
190 pcm_read_seek,
191 };
192
193 #ifdef CONFIG_ENCODERS
194 static AVOutputFormat au_oformat = {
195 "au",
196 "SUN AU Format",
197 "audio/basic",
198 "au",
199 0,
200 CODEC_ID_PCM_S16BE,
201 CODEC_ID_NONE,
202 au_write_header,
203 au_write_packet,
204 au_write_trailer,
205 };
206 #endif //CONFIG_ENCODERS
207
208 int au_init(void)
209 {
210 av_register_input_format(&au_iformat);
211 #ifdef CONFIG_ENCODERS
212 av_register_output_format(&au_oformat);
213 #endif //CONFIG_ENCODERS
214 return 0;
215 }