suppressed packet size dependancy
[libav.git] / libav / 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)(~0))
33
34 /* The ffmpeg codecs we support, and the IDs they have in the file */
35 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 /* AUDIO_FILE header */
43 int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
44 {
45 int tag;
46
47 tag = codec_get_tag(codec_au_tags, enc->codec_id);
48 if (tag == 0)
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)tag); /* codec ID */
54 put_be32(pb, enc->sample_rate);
55 put_be32(pb, (UINT32)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 UINT8 *buf, int size, int force_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)(file_size - 24));
94 url_fseek(pb, file_size, SEEK_SET);
95
96 put_flush_packet(pb);
97 }
98
99 return 0;
100 }
101
102 static int au_probe(AVProbeData *p)
103 {
104 /* check file header */
105 if (p->buf_size <= 24)
106 return 0;
107 if (p->buf[0] == '.' && p->buf[1] == 's' &&
108 p->buf[2] == 'n' && p->buf[3] == 'd')
109 return AVPROBE_SCORE_MAX;
110 else
111 return 0;
112 }
113
114 /* au input */
115 static int au_read_header(AVFormatContext *s,
116 AVFormatParameters *ap)
117 {
118 int size;
119 unsigned int tag;
120 ByteIOContext *pb = &s->pb;
121 unsigned int id, codec, channels, rate;
122 AVStream *st;
123
124 /* check ".snd" header */
125 tag = get_le32(pb);
126 if (tag != MKTAG('.', 's', 'n', 'd'))
127 return -1;
128 size = get_be32(pb); /* header size */
129 get_be32(pb); /* data size */
130
131 id = get_be32(pb);
132 rate = get_be32(pb);
133 channels = get_be32(pb);
134
135 codec = codec_get_id(codec_au_tags, id);
136
137 if (size >= 24) {
138 /* skip unused data */
139 url_fseek(pb, size - 24, SEEK_CUR);
140 }
141
142 /* now we are ready: build format streams */
143 st = av_malloc(sizeof(AVStream));
144 if (!st)
145 return -1;
146 s->nb_streams = 1;
147 s->streams[0] = st;
148
149 st->id = 0;
150
151 st->codec.codec_type = CODEC_TYPE_AUDIO;
152 st->codec.codec_tag = id;
153 st->codec.codec_id = codec;
154 st->codec.channels = channels;
155 st->codec.sample_rate = rate;
156 return 0;
157 }
158
159 #define MAX_SIZE 4096
160
161 static int au_read_packet(AVFormatContext *s,
162 AVPacket *pkt)
163 {
164 int ret;
165
166 if (url_feof(&s->pb))
167 return -EIO;
168 if (av_new_packet(pkt, MAX_SIZE))
169 return -EIO;
170 pkt->stream_index = 0;
171
172 ret = get_buffer(&s->pb, pkt->data, pkt->size);
173 if (ret < 0)
174 av_free_packet(pkt);
175 /* note: we need to modify the packet size here to handle the last
176 packet */
177 pkt->size = ret;
178 return 0;
179 }
180
181 static int au_read_close(AVFormatContext *s)
182 {
183 return 0;
184 }
185
186 static AVInputFormat au_iformat = {
187 "au",
188 "SUN AU Format",
189 0,
190 au_probe,
191 au_read_header,
192 au_read_packet,
193 au_read_close,
194 };
195
196 static AVOutputFormat au_oformat = {
197 "au",
198 "SUN AU Format",
199 "audio/basic",
200 "au",
201 0,
202 CODEC_ID_PCM_S16BE,
203 CODEC_ID_NONE,
204 au_write_header,
205 au_write_packet,
206 au_write_trailer,
207 };
208
209 int au_init(void)
210 {
211 av_register_input_format(&au_iformat);
212 av_register_output_format(&au_oformat);
213 return 0;
214 }