* Many, many changes to make it work (mostly). Information snagged from
[libav.git] / libav / audio.c
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1/*
2 * Linux audio play and grab interface
3 * Copyright (c) 2000, 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 */
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19#include "avformat.h"
20
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21#include <stdlib.h>
22#include <stdio.h>
23#include <string.h>
24#include <linux/soundcard.h>
25#include <unistd.h>
26#include <fcntl.h>
27#include <sys/ioctl.h>
28#include <sys/mman.h>
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29#include <sys/time.h>
30
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31const char *audio_device = "/dev/dsp";
32
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33#define AUDIO_BLOCK_SIZE 4096
34
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35typedef struct {
36 int fd;
4972b26f 37 int sample_rate;
de6d9b64 38 int channels;
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39 int frame_size; /* in bytes ! */
40 int codec_id;
41 UINT8 buffer[AUDIO_BLOCK_SIZE];
42 int buffer_ptr;
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43} AudioData;
44
4972b26f 45static int audio_open(AudioData *s, int is_output)
de6d9b64 46{
4972b26f 47 int audio_fd;
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48 int tmp, err;
49
de6d9b64 50 /* open linux audio device */
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51 if (is_output)
52 audio_fd = open(audio_device, O_WRONLY);
de6d9b64 53 else
4972b26f 54 audio_fd = open(audio_device, O_RDONLY);
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55 if (audio_fd < 0) {
56 perror(audio_device);
57 return -EIO;
58 }
59
60 /* non blocking mode */
61 fcntl(audio_fd, F_SETFL, O_NONBLOCK);
62
4972b26f 63 s->frame_size = AUDIO_BLOCK_SIZE;
de6d9b64 64#if 0
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65 tmp = (NB_FRAGMENTS << 16) | FRAGMENT_BITS;
66 err = ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &tmp);
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67 if (err < 0) {
68 perror("SNDCTL_DSP_SETFRAGMENT");
69 }
70#endif
71
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72 /* select format : favour native format */
73 err = ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &tmp);
74
75#ifdef WORDS_BIGENDIAN
76 if (tmp & AFMT_S16_BE) {
77 tmp = AFMT_S16_BE;
78 } else if (tmp & AFMT_S16_LE) {
79 tmp = AFMT_S16_LE;
80 } else {
81 tmp = 0;
82 }
83#else
84 if (tmp & AFMT_S16_LE) {
85 tmp = AFMT_S16_LE;
86 } else if (tmp & AFMT_S16_BE) {
87 tmp = AFMT_S16_BE;
88 } else {
89 tmp = 0;
90 }
91#endif
92
93 switch(tmp) {
94 case AFMT_S16_LE:
95 s->codec_id = CODEC_ID_PCM_S16LE;
96 break;
97 case AFMT_S16_BE:
98 s->codec_id = CODEC_ID_PCM_S16BE;
99 break;
100 default:
101 fprintf(stderr, "Soundcard does not support 16 bit sample format\n");
102 close(audio_fd);
103 return -EIO;
104 }
105 err=ioctl(audio_fd, SNDCTL_DSP_SETFMT, &tmp);
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106 if (err < 0) {
107 perror("SNDCTL_DSP_SETFMT");
108 goto fail;
109 }
110
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111 tmp = (s->channels == 2);
112 err = ioctl(audio_fd, SNDCTL_DSP_STEREO, &tmp);
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113 if (err < 0) {
114 perror("SNDCTL_DSP_STEREO");
115 goto fail;
116 }
117
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118 tmp = s->sample_rate;
119 err = ioctl(audio_fd, SNDCTL_DSP_SPEED, &tmp);
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120 if (err < 0) {
121 perror("SNDCTL_DSP_SPEED");
122 goto fail;
123 }
4972b26f 124 s->sample_rate = tmp; /* store real sample rate */
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125 s->fd = audio_fd;
126
127 return 0;
128 fail:
129 close(audio_fd);
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130 return -EIO;
131}
132
4972b26f 133static int audio_close(AudioData *s)
de6d9b64 134{
de6d9b64 135 close(s->fd);
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136 return 0;
137}
138
139/* sound output support */
140static int audio_write_header(AVFormatContext *s1)
141{
142 AudioData *s;
143 AVStream *st;
144 int ret;
145
146 s = av_mallocz(sizeof(AudioData));
147 if (!s)
148 return -ENOMEM;
149 s1->priv_data = s;
150
151 st = s1->streams[0];
152 s->sample_rate = st->codec.sample_rate;
153 s->channels = st->codec.channels;
154 ret = audio_open(s, 1);
155 if (ret < 0) {
156 free(s);
157 return -EIO;
158 } else {
159 return 0;
160 }
161}
162
163static int audio_write_packet(AVFormatContext *s1, int stream_index,
10bb7023 164 UINT8 *buf, int size, int force_pts)
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165{
166 AudioData *s = s1->priv_data;
167 int len, ret;
168
169 while (size > 0) {
170 len = AUDIO_BLOCK_SIZE - s->buffer_ptr;
171 if (len > size)
172 len = size;
173 memcpy(s->buffer + s->buffer_ptr, buf, len);
174 s->buffer_ptr += len;
175 if (s->buffer_ptr >= AUDIO_BLOCK_SIZE) {
176 for(;;) {
177 ret = write(s->fd, s->buffer, AUDIO_BLOCK_SIZE);
178 if (ret != 0)
179 break;
180 if (ret < 0 && (errno != EAGAIN && errno != EINTR))
181 return -EIO;
182 }
183 s->buffer_ptr = 0;
184 }
185 buf += len;
186 size -= len;
187 }
188 return 0;
189}
190
191static int audio_write_trailer(AVFormatContext *s1)
192{
193 AudioData *s = s1->priv_data;
194
195 audio_close(s);
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196 free(s);
197 return 0;
198}
199
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200/* grab support */
201
202static int audio_read_header(AVFormatContext *s1, AVFormatParameters *ap)
203{
204 AudioData *s;
205 AVStream *st;
206 int ret;
207
208 if (!ap || ap->sample_rate <= 0 || ap->channels <= 0)
209 return -1;
210
211 s = av_mallocz(sizeof(AudioData));
212 if (!s)
213 return -ENOMEM;
214 st = av_mallocz(sizeof(AVStream));
215 if (!st) {
216 free(s);
217 return -ENOMEM;
218 }
219 s1->priv_data = s;
220 s1->nb_streams = 1;
221 s1->streams[0] = st;
222 s->sample_rate = ap->sample_rate;
223 s->channels = ap->channels;
224
225 ret = audio_open(s, 0);
226 if (ret < 0) {
227 free(st);
228 free(s);
229 return -EIO;
230 } else {
231 /* take real parameters */
232 st->codec.codec_type = CODEC_TYPE_AUDIO;
233 st->codec.codec_id = s->codec_id;
234 st->codec.sample_rate = s->sample_rate;
235 st->codec.channels = s->channels;
236 return 0;
237 }
238}
239
240static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
241{
242 AudioData *s = s1->priv_data;
243 int ret;
244
245 if (av_new_packet(pkt, s->frame_size) < 0)
246 return -EIO;
247 for(;;) {
248 ret = read(s->fd, pkt->data, pkt->size);
249 if (ret > 0)
250 break;
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251 if (ret == -1 && (errno == EAGAIN || errno == EINTR)) {
252 av_free_packet(pkt);
253 pkt->size = 0;
254 return 0;
255 }
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256 if (!(ret == 0 || (ret == -1 && (errno == EAGAIN || errno == EINTR)))) {
257 av_free_packet(pkt);
258 return -EIO;
259 }
260 }
261 pkt->size = ret;
262 return 0;
263}
264
265static int audio_read_close(AVFormatContext *s1)
266{
267 AudioData *s = s1->priv_data;
268
269 audio_close(s);
270 free(s);
271 return 0;
272}
273
274AVFormat audio_device_format = {
275 "audio_device",
276 "audio grab and output",
277 "",
278 "",
279 /* XXX: we make the assumption that the soundcard accepts this format */
280 /* XXX: find better solution with "preinit" method, needed also in
281 other formats */
282#ifdef WORDS_BIGENDIAN
283 CODEC_ID_PCM_S16BE,
284#else
285 CODEC_ID_PCM_S16LE,
286#endif
287 CODEC_ID_NONE,
288 audio_write_header,
289 audio_write_packet,
290 audio_write_trailer,
291
292 audio_read_header,
293 audio_read_packet,
294 audio_read_close,
295 NULL,
296 AVFMT_NOFILE,
de6d9b64 297};