Initial revision
[libav.git] / libav / wav.c
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1/*
2 * WAV encoder and decoder
3 * Copyright (c) 2001 Gerard Lantau.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program 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
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19#include <stdlib.h>
20#include <stdio.h>
21#include <netinet/in.h>
22#include <string.h>
23#include <errno.h>
24#include "avformat.h"
25#include "avi.h"
26
27typedef struct {
28 offset_t data;
29} WAVContext;
30
31static int wav_write_header(AVFormatContext *s)
32{
33 WAVContext *wav;
34 ByteIOContext *pb = &s->pb;
35 offset_t fmt;
36
37 wav = malloc(sizeof(WAVContext));
38 if (!wav)
39 return -1;
40 memset(wav, 0, sizeof(WAVContext));
41 s->priv_data = wav;
42
43 put_tag(pb, "RIFF");
44 put_le32(pb, 0); /* file length */
45 put_tag(pb, "WAVE");
46
47 /* format header */
48 fmt = start_tag(pb, "fmt ");
49 put_wav_header(pb, &s->streams[0]->codec);
50 end_tag(pb, fmt);
51
52 /* data header */
53 wav->data = start_tag(pb, "data");
54
55 put_flush_packet(pb);
56
57 return 0;
58}
59
60static int wav_write_packet(AVFormatContext *s, int stream_index_ptr,
61 UINT8 *buf, int size)
62{
63 ByteIOContext *pb = &s->pb;
64 put_buffer(pb, buf, size);
65 return 0;
66}
67
68static int wav_write_trailer(AVFormatContext *s)
69{
70 ByteIOContext *pb = &s->pb;
71 WAVContext *wav = s->priv_data;
72 offset_t file_size;
73
74 if (!url_is_streamed(&s->pb)) {
75 end_tag(pb, wav->data);
76
77 /* update file size */
78 file_size = url_ftell(pb);
79 url_fseek(pb, 4, SEEK_SET);
80 put_le32(pb, file_size);
81 url_fseek(pb, file_size, SEEK_SET);
82
83 put_flush_packet(pb);
84 }
85
86 free(wav);
87 return 0;
88}
89
90/* return the size of the found tag */
91/* XXX: > 2GB ? */
92static int find_tag(ByteIOContext *pb, int tag1)
93{
94 unsigned int tag;
95 int size;
96
97 for(;;) {
98 if (url_feof(pb))
99 return -1;
100 tag = get_le32(pb);
101 size = get_le32(pb);
102 if (tag == tag1)
103 break;
104 url_fseek(pb, size, SEEK_CUR);
105 }
106 if (size < 0)
107 size = 0x7fffffff;
108 return size;
109}
110
111/* wav input */
112static int wav_read_header(AVFormatContext *s,
113 AVFormatParameters *ap)
114{
115 int size;
116 unsigned int tag;
117 ByteIOContext *pb = &s->pb;
118 unsigned int id, channels, rate, bit_rate, extra_size;
119 AVStream *st;
120
121 /* check RIFF header */
122 tag = get_le32(pb);
123
124 if (tag != MKTAG('R', 'I', 'F', 'F'))
125 return -1;
126 get_le32(pb); /* file size */
127 tag = get_le32(pb);
128 if (tag != MKTAG('W', 'A', 'V', 'E'))
129 return -1;
130
131 /* parse fmt header */
132 size = find_tag(pb, MKTAG('f', 'm', 't', ' '));
133 if (size < 0)
134 return -1;
135 id = get_le16(pb);
136 channels = get_le16(pb);
137 rate = get_le32(pb);
138 bit_rate = get_le32(pb) * 8;
139 get_le16(pb); /* block align */
140 get_le16(pb); /* bits per sample */
141 if (size >= 18) {
142 /* wav_extra_size */
143 extra_size = get_le16(pb);
144 /* skip unused data */
145 url_fseek(pb, size - 18, SEEK_CUR);
146 }
147
148 size = find_tag(pb, MKTAG('d', 'a', 't', 'a'));
149 if (size < 0)
150 return -1;
151
152 /* now we are ready: build format streams */
153 st = malloc(sizeof(AVStream));
154 if (!st)
155 return -1;
156 s->nb_streams = 1;
157 s->streams[0] = st;
158
159 st->id = 0;
160
161 st->codec.codec_type = CODEC_TYPE_AUDIO;
162 st->codec.codec_tag = id;
163 st->codec.codec_id = codec_get_id(codec_wav_tags, id);
164 st->codec.channels = channels;
165 st->codec.sample_rate = rate;
166 return 0;
167}
168
169#define MAX_SIZE 4096
170
171static int wav_read_packet(AVFormatContext *s,
172 AVPacket *pkt)
173{
174 int packet_size, n, ret;
175
176 if (url_feof(&s->pb))
177 return -EIO;
178 packet_size = url_get_packet_size(&s->pb);
179 n = MAX_SIZE / packet_size;
180 if (n <= 0)
181 return n = 1;
182 if (av_new_packet(pkt, n * packet_size))
183 return -EIO;
184 pkt->stream_index = 0;
185
186 ret = get_buffer(&s->pb, pkt->data, pkt->size);
187 if (ret < 0)
188 av_free_packet(pkt);
189 return ret;
190}
191
192static int wav_read_close(AVFormatContext *s)
193{
194 return 0;
195}
196
197AVFormat wav_format = {
198 "wav",
199 "wav format",
200 "audio/x-wav",
201 "wav",
202 CODEC_ID_PCM,
203 CODEC_ID_NONE,
204 wav_write_header,
205 wav_write_packet,
206 wav_write_trailer,
207
208 wav_read_header,
209 wav_read_packet,
210 wav_read_close,
211};