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[libav.git] / libavformat / audio.c
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1/*
2 * Linux audio play and grab interface
19720f15 3 * Copyright (c) 2000, 2001 Fabrice Bellard.
de6d9b64 4 *
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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.
de6d9b64 9 *
19720f15 10 * This library is distributed in the hope that it will be useful,
de6d9b64 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
de6d9b64 14 *
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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
de6d9b64 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>
b13788c5 24#include <sys/soundcard.h>
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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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31#define AUDIO_BLOCK_SIZE 4096
32
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33typedef struct {
34 int fd;
4972b26f 35 int sample_rate;
de6d9b64 36 int channels;
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37 int frame_size; /* in bytes ! */
38 int codec_id;
1de1cce2 39 int flip_left : 1;
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40 UINT8 buffer[AUDIO_BLOCK_SIZE];
41 int buffer_ptr;
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42} AudioData;
43
7f172339 44static int audio_open(AudioData *s, int is_output, const char *audio_device)
de6d9b64 45{
4972b26f 46 int audio_fd;
de6d9b64 47 int tmp, err;
1de1cce2 48 char *flip = getenv("AUDIO_FLIP_LEFT");
de6d9b64 49
de6d9b64 50 /* open linux audio device */
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51 if (!audio_device)
52 audio_device = "/dev/dsp";
53
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54 if (is_output)
55 audio_fd = open(audio_device, O_WRONLY);
de6d9b64 56 else
4972b26f 57 audio_fd = open(audio_device, O_RDONLY);
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58 if (audio_fd < 0) {
59 perror(audio_device);
60 return -EIO;
61 }
62
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63 if (flip && *flip == '1') {
64 s->flip_left = 1;
65 }
66
de6d9b64 67 /* non blocking mode */
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68 if (!is_output)
69 fcntl(audio_fd, F_SETFL, O_NONBLOCK);
de6d9b64 70
4972b26f 71 s->frame_size = AUDIO_BLOCK_SIZE;
de6d9b64 72#if 0
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73 tmp = (NB_FRAGMENTS << 16) | FRAGMENT_BITS;
74 err = ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &tmp);
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75 if (err < 0) {
76 perror("SNDCTL_DSP_SETFRAGMENT");
77 }
78#endif
79
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80 /* select format : favour native format */
81 err = ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &tmp);
82
83#ifdef WORDS_BIGENDIAN
84 if (tmp & AFMT_S16_BE) {
85 tmp = AFMT_S16_BE;
86 } else if (tmp & AFMT_S16_LE) {
87 tmp = AFMT_S16_LE;
88 } else {
89 tmp = 0;
90 }
91#else
92 if (tmp & AFMT_S16_LE) {
93 tmp = AFMT_S16_LE;
94 } else if (tmp & AFMT_S16_BE) {
95 tmp = AFMT_S16_BE;
96 } else {
97 tmp = 0;
98 }
99#endif
100
101 switch(tmp) {
102 case AFMT_S16_LE:
103 s->codec_id = CODEC_ID_PCM_S16LE;
104 break;
105 case AFMT_S16_BE:
106 s->codec_id = CODEC_ID_PCM_S16BE;
107 break;
108 default:
109 fprintf(stderr, "Soundcard does not support 16 bit sample format\n");
110 close(audio_fd);
111 return -EIO;
112 }
113 err=ioctl(audio_fd, SNDCTL_DSP_SETFMT, &tmp);
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114 if (err < 0) {
115 perror("SNDCTL_DSP_SETFMT");
116 goto fail;
117 }
118
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119 tmp = (s->channels == 2);
120 err = ioctl(audio_fd, SNDCTL_DSP_STEREO, &tmp);
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121 if (err < 0) {
122 perror("SNDCTL_DSP_STEREO");
123 goto fail;
124 }
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125 if (tmp)
126 s->channels = 2;
de6d9b64 127
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128 tmp = s->sample_rate;
129 err = ioctl(audio_fd, SNDCTL_DSP_SPEED, &tmp);
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130 if (err < 0) {
131 perror("SNDCTL_DSP_SPEED");
132 goto fail;
133 }
4972b26f 134 s->sample_rate = tmp; /* store real sample rate */
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135 s->fd = audio_fd;
136
137 return 0;
138 fail:
139 close(audio_fd);
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140 return -EIO;
141}
142
4972b26f 143static int audio_close(AudioData *s)
de6d9b64 144{
de6d9b64 145 close(s->fd);
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146 return 0;
147}
148
149/* sound output support */
150static int audio_write_header(AVFormatContext *s1)
151{
c9a65ca8 152 AudioData *s = s1->priv_data;
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153 AVStream *st;
154 int ret;
155
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156 st = s1->streams[0];
157 s->sample_rate = st->codec.sample_rate;
158 s->channels = st->codec.channels;
7f172339 159 ret = audio_open(s, 1, NULL);
4972b26f 160 if (ret < 0) {
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161 return -EIO;
162 } else {
163 return 0;
164 }
165}
166
167static int audio_write_packet(AVFormatContext *s1, int stream_index,
10bb7023 168 UINT8 *buf, int size, int force_pts)
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169{
170 AudioData *s = s1->priv_data;
171 int len, ret;
172
173 while (size > 0) {
174 len = AUDIO_BLOCK_SIZE - s->buffer_ptr;
175 if (len > size)
176 len = size;
177 memcpy(s->buffer + s->buffer_ptr, buf, len);
178 s->buffer_ptr += len;
179 if (s->buffer_ptr >= AUDIO_BLOCK_SIZE) {
180 for(;;) {
181 ret = write(s->fd, s->buffer, AUDIO_BLOCK_SIZE);
4364a3e0 182 if (ret > 0)
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183 break;
184 if (ret < 0 && (errno != EAGAIN && errno != EINTR))
185 return -EIO;
186 }
187 s->buffer_ptr = 0;
188 }
189 buf += len;
190 size -= len;
191 }
192 return 0;
193}
194
195static int audio_write_trailer(AVFormatContext *s1)
196{
197 AudioData *s = s1->priv_data;
198
199 audio_close(s);
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200 return 0;
201}
202
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203/* grab support */
204
205static int audio_read_header(AVFormatContext *s1, AVFormatParameters *ap)
206{
c9a65ca8 207 AudioData *s = s1->priv_data;
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208 AVStream *st;
209 int ret;
210
211 if (!ap || ap->sample_rate <= 0 || ap->channels <= 0)
212 return -1;
213
c9a65ca8 214 st = av_new_stream(s1, 0);
4972b26f 215 if (!st) {
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216 return -ENOMEM;
217 }
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218 s->sample_rate = ap->sample_rate;
219 s->channels = ap->channels;
220
7f172339 221 ret = audio_open(s, 0, ap->device);
4972b26f 222 if (ret < 0) {
1ea4f593 223 av_free(st);
4972b26f 224 return -EIO;
4972b26f 225 }
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226
227 /* take real parameters */
228 st->codec.codec_type = CODEC_TYPE_AUDIO;
229 st->codec.codec_id = s->codec_id;
230 st->codec.sample_rate = s->sample_rate;
231 st->codec.channels = s->channels;
232
233 av_set_pts_info(s1, 48, 1, 1000000); /* 48 bits pts in us */
234 return 0;
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235}
236
237static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
238{
239 AudioData *s = s1->priv_data;
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240 int ret, bdelay;
241 int64_t cur_time;
242 struct audio_buf_info abufi;
243
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244 if (av_new_packet(pkt, s->frame_size) < 0)
245 return -EIO;
246 for(;;) {
247 ret = read(s->fd, pkt->data, pkt->size);
248 if (ret > 0)
249 break;
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250 if (ret == -1 && (errno == EAGAIN || errno == EINTR)) {
251 av_free_packet(pkt);
252 pkt->size = 0;
253 return 0;
254 }
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255 if (!(ret == 0 || (ret == -1 && (errno == EAGAIN || errno == EINTR)))) {
256 av_free_packet(pkt);
257 return -EIO;
258 }
259 }
260 pkt->size = ret;
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261
262 /* compute pts of the start of the packet */
263 cur_time = av_gettime();
264 bdelay = ret;
265 if (ioctl(s->fd, SNDCTL_DSP_GETISPACE, &abufi) == 0) {
266 bdelay += abufi.bytes;
267 }
268 /* substract time represented by the number of bytes in the audio fifo */
269 cur_time -= (bdelay * 1000000LL) / (s->sample_rate * s->channels);
270
271 /* convert to wanted units */
272 pkt->pts = cur_time & ((1LL << 48) - 1);
273
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274 if (s->flip_left && s->channels == 2) {
275 int i;
276 short *p = (short *) pkt->data;
277
278 for (i = 0; i < ret; i += 4) {
279 *p = ~*p;
280 p += 2;
281 }
282 }
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283 return 0;
284}
285
286static int audio_read_close(AVFormatContext *s1)
287{
288 AudioData *s = s1->priv_data;
289
290 audio_close(s);
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291 return 0;
292}
293
c18a2692 294static AVInputFormat audio_in_format = {
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295 "audio_device",
296 "audio grab and output",
297 sizeof(AudioData),
298 NULL,
299 audio_read_header,
300 audio_read_packet,
301 audio_read_close,
bb76a117 302 .flags = AVFMT_NOFILE,
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303};
304
c18a2692 305static AVOutputFormat audio_out_format = {
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306 "audio_device",
307 "audio grab and output",
308 "",
309 "",
c9a65ca8 310 sizeof(AudioData),
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311 /* XXX: we make the assumption that the soundcard accepts this format */
312 /* XXX: find better solution with "preinit" method, needed also in
313 other formats */
314#ifdef WORDS_BIGENDIAN
315 CODEC_ID_PCM_S16BE,
316#else
317 CODEC_ID_PCM_S16LE,
318#endif
319 CODEC_ID_NONE,
320 audio_write_header,
321 audio_write_packet,
322 audio_write_trailer,
bb76a117 323 .flags = AVFMT_NOFILE,
de6d9b64 324};
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325
326int audio_init(void)
327{
328 av_register_input_format(&audio_in_format);
329 av_register_output_format(&audio_out_format);
330 return 0;
331}