121d85465SGoran Mekić /*
24d846d26SWarner Losh * SPDX-License-Identifier: BSD-2-Clause
321d85465SGoran Mekić *
421d85465SGoran Mekić * Copyright (c) 2021 Goran Mekić
521d85465SGoran Mekić *
621d85465SGoran Mekić * Redistribution and use in source and binary forms, with or without
721d85465SGoran Mekić * modification, are permitted provided that the following conditions
821d85465SGoran Mekić * are met:
921d85465SGoran Mekić * 1. Redistributions of source code must retain the above copyright
1021d85465SGoran Mekić * notice, this list of conditions and the following disclaimer.
1121d85465SGoran Mekić * 2. Redistributions in binary form must reproduce the above copyright
1221d85465SGoran Mekić * notice, this list of conditions and the following disclaimer in the
1321d85465SGoran Mekić * documentation and/or other materials provided with the distribution.
1421d85465SGoran Mekić *
1521d85465SGoran Mekić * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1621d85465SGoran Mekić * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1721d85465SGoran Mekić * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1821d85465SGoran Mekić * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1921d85465SGoran Mekić * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2021d85465SGoran Mekić * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2121d85465SGoran Mekić * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2221d85465SGoran Mekić * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2321d85465SGoran Mekić * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2421d85465SGoran Mekić * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2521d85465SGoran Mekić * SUCH DAMAGE.
2621d85465SGoran Mekić */
2721d85465SGoran Mekić
2821d85465SGoran Mekić #include <sys/soundcard.h>
2921d85465SGoran Mekić #include <errno.h>
3021d85465SGoran Mekić #include <fcntl.h>
3121d85465SGoran Mekić #include <stdio.h>
3221d85465SGoran Mekić #include <stdlib.h>
3321d85465SGoran Mekić #include <string.h>
3421d85465SGoran Mekić #include <unistd.h>
3521d85465SGoran Mekić
3621d85465SGoran Mekić
3721d85465SGoran Mekić #ifndef SAMPLE_SIZE
3821d85465SGoran Mekić #define SAMPLE_SIZE 16
3921d85465SGoran Mekić #endif
4021d85465SGoran Mekić
4121d85465SGoran Mekić /* Format can be unsigned, in which case replace S with U */
4221d85465SGoran Mekić #if SAMPLE_SIZE == 32
4321d85465SGoran Mekić typedef int32_t sample_t;
4421d85465SGoran Mekić int format = AFMT_S32_NE; /* Signed 32bit native endian format */
4521d85465SGoran Mekić #elif SAMPLE_SIZE == 16
4621d85465SGoran Mekić typedef int16_t sample_t;
4721d85465SGoran Mekić int format = AFMT_S16_NE; /* Signed 16bit native endian format */
4821d85465SGoran Mekić #elif SAMPLE_SIZE == 8
4921d85465SGoran Mekić typedef int8_t sample_t;
5021d85465SGoran Mekić int format = AFMT_S8_NE; /* Signed 8bit native endian format */
5121d85465SGoran Mekić #else
5221d85465SGoran Mekić #error Unsupported sample format!
5321d85465SGoran Mekić typedef int32_t sample_t;
5421d85465SGoran Mekić int format = AFMT_S32_NE; /* Not a real value, just silencing
5521d85465SGoran Mekić * compiler errors */
5621d85465SGoran Mekić #endif
5721d85465SGoran Mekić
5821d85465SGoran Mekić
5921d85465SGoran Mekić
6021d85465SGoran Mekić /*
6121d85465SGoran Mekić * Minimal configuration for OSS
6221d85465SGoran Mekić * For real world applications, this structure will probably contain many
6321d85465SGoran Mekić * more fields
6421d85465SGoran Mekić */
6521d85465SGoran Mekić typedef struct config {
6621d85465SGoran Mekić char *device;
6721d85465SGoran Mekić int channels;
6821d85465SGoran Mekić int fd;
6921d85465SGoran Mekić int format;
7021d85465SGoran Mekić int frag;
7121d85465SGoran Mekić int sample_count;
7221d85465SGoran Mekić int sample_rate;
7321d85465SGoran Mekić int sample_size;
7421d85465SGoran Mekić int chsamples;
7521d85465SGoran Mekić int mmap;
7621d85465SGoran Mekić oss_audioinfo audio_info;
7721d85465SGoran Mekić audio_buf_info buffer_info;
7821d85465SGoran Mekić } config_t;
7921d85465SGoran Mekić
8021d85465SGoran Mekić
8121d85465SGoran Mekić /*
8221d85465SGoran Mekić * Error state is indicated by value=-1 in which case application exits
8321d85465SGoran Mekić * with error
8421d85465SGoran Mekić */
8521d85465SGoran Mekić static inline void
check_error(const int value,const char * message)8621d85465SGoran Mekić check_error(const int value, const char *message)
8721d85465SGoran Mekić {
8821d85465SGoran Mekić if (value == -1) {
8921d85465SGoran Mekić fprintf(stderr, "OSS error: %s %s\n", message, strerror(errno));
9021d85465SGoran Mekić exit(1);
9121d85465SGoran Mekić }
9221d85465SGoran Mekić }
9321d85465SGoran Mekić
9421d85465SGoran Mekić
9521d85465SGoran Mekić
9621d85465SGoran Mekić /* Calculate frag by giving it minimal size of buffer */
9721d85465SGoran Mekić static inline int
size2frag(int x)9821d85465SGoran Mekić size2frag(int x)
9921d85465SGoran Mekić {
10021d85465SGoran Mekić int frag = 0;
10121d85465SGoran Mekić
10221d85465SGoran Mekić while ((1 << frag) < x) {
10321d85465SGoran Mekić ++frag;
10421d85465SGoran Mekić }
10521d85465SGoran Mekić return frag;
10621d85465SGoran Mekić }
10721d85465SGoran Mekić
10821d85465SGoran Mekić
10921d85465SGoran Mekić /*
11021d85465SGoran Mekić * Split input buffer into channels. Input buffer is in interleaved format
11121d85465SGoran Mekić * which means if we have 2 channels (L and R), this is what the buffer of
11221d85465SGoran Mekić * 8 samples would contain: L,R,L,R,L,R,L,R. The result are two channels
11321d85465SGoran Mekić * containing: L,L,L,L and R,R,R,R.
11421d85465SGoran Mekić */
11521d85465SGoran Mekić void
oss_split(config_t * config,sample_t * input,sample_t * output)11621d85465SGoran Mekić oss_split(config_t *config, sample_t *input, sample_t *output)
11721d85465SGoran Mekić {
11821d85465SGoran Mekić int channel;
11921d85465SGoran Mekić int index;
12021d85465SGoran Mekić
12121d85465SGoran Mekić for (int i = 0; i < config->sample_count; ++i) {
12221d85465SGoran Mekić channel = i % config->channels;
12321d85465SGoran Mekić index = i / config->channels;
12421d85465SGoran Mekić output[channel * index] = input[i];
12521d85465SGoran Mekić }
12621d85465SGoran Mekić }
12721d85465SGoran Mekić
12821d85465SGoran Mekić
12921d85465SGoran Mekić /*
13021d85465SGoran Mekić * Convert channels into interleaved format and place it in output
13121d85465SGoran Mekić * buffer
13221d85465SGoran Mekić */
13321d85465SGoran Mekić void
oss_merge(config_t * config,sample_t * input,sample_t * output)13421d85465SGoran Mekić oss_merge(config_t *config, sample_t *input, sample_t *output)
13521d85465SGoran Mekić {
13621d85465SGoran Mekić for (int channel = 0; channel < config->channels; ++channel) {
13721d85465SGoran Mekić for (int index = 0; index < config->chsamples; ++index) {
13821d85465SGoran Mekić output[index * config->channels + channel] = input[channel * index];
13921d85465SGoran Mekić }
14021d85465SGoran Mekić }
14121d85465SGoran Mekić }
14221d85465SGoran Mekić
14321d85465SGoran Mekić void
oss_init(config_t * config)14421d85465SGoran Mekić oss_init(config_t *config)
14521d85465SGoran Mekić {
14621d85465SGoran Mekić int error;
14721d85465SGoran Mekić int tmp;
14821d85465SGoran Mekić
14921d85465SGoran Mekić /* Open the device for read and write */
15021d85465SGoran Mekić config->fd = open(config->device, O_RDWR);
15121d85465SGoran Mekić check_error(config->fd, "open");
15221d85465SGoran Mekić
15321d85465SGoran Mekić /* Get device information */
15421d85465SGoran Mekić config->audio_info.dev = -1;
15521d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_ENGINEINFO, &(config->audio_info));
15621d85465SGoran Mekić check_error(error, "SNDCTL_ENGINEINFO");
15721d85465SGoran Mekić printf("min_channels: %d\n", config->audio_info.min_channels);
15821d85465SGoran Mekić printf("max_channels: %d\n", config->audio_info.max_channels);
15921d85465SGoran Mekić printf("latency: %d\n", config->audio_info.latency);
16021d85465SGoran Mekić printf("handle: %s\n", config->audio_info.handle);
16121d85465SGoran Mekić if (config->audio_info.min_rate > config->sample_rate || config->sample_rate > config->audio_info.max_rate) {
16221d85465SGoran Mekić fprintf(stderr, "%s doesn't support chosen ", config->device);
16321d85465SGoran Mekić fprintf(stderr, "samplerate of %dHz!\n", config->sample_rate);
16421d85465SGoran Mekić exit(1);
16521d85465SGoran Mekić }
16621d85465SGoran Mekić if (config->channels < 1) {
16721d85465SGoran Mekić config->channels = config->audio_info.max_channels;
16821d85465SGoran Mekić }
16921d85465SGoran Mekić
17021d85465SGoran Mekić /*
17121d85465SGoran Mekić * If device is going to be used in mmap mode, disable all format
17221d85465SGoran Mekić * conversions. Official OSS documentation states error code should not be
17321d85465SGoran Mekić * checked. http://manuals.opensound.com/developer/mmap_test.c.html#LOC10
17421d85465SGoran Mekić */
17521d85465SGoran Mekić if (config->mmap) {
17621d85465SGoran Mekić tmp = 0;
17721d85465SGoran Mekić ioctl(config->fd, SNDCTL_DSP_COOKEDMODE, &tmp);
17821d85465SGoran Mekić }
17921d85465SGoran Mekić
18021d85465SGoran Mekić /*
18121d85465SGoran Mekić * Set number of channels. If number of channels is chosen to the value
18221d85465SGoran Mekić * near the one wanted, save it in config
18321d85465SGoran Mekić */
18421d85465SGoran Mekić tmp = config->channels;
18521d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_DSP_CHANNELS, &tmp);
18621d85465SGoran Mekić check_error(error, "SNDCTL_DSP_CHANNELS");
18721d85465SGoran Mekić if (tmp != config->channels) { /* or check if tmp is close enough? */
18821d85465SGoran Mekić fprintf(stderr, "%s doesn't support chosen ", config->device);
18921d85465SGoran Mekić fprintf(stderr, "channel count of %d", config->channels);
19021d85465SGoran Mekić fprintf(stderr, ", set to %d!\n", tmp);
19121d85465SGoran Mekić }
19221d85465SGoran Mekić config->channels = tmp;
19321d85465SGoran Mekić
19421d85465SGoran Mekić /* Set format, or bit size: 8, 16, 24 or 32 bit sample */
19521d85465SGoran Mekić tmp = config->format;
19621d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_DSP_SETFMT, &tmp);
19721d85465SGoran Mekić check_error(error, "SNDCTL_DSP_SETFMT");
19821d85465SGoran Mekić if (tmp != config->format) {
19921d85465SGoran Mekić fprintf(stderr, "%s doesn't support chosen sample format!\n", config->device);
20021d85465SGoran Mekić exit(1);
20121d85465SGoran Mekić }
20221d85465SGoran Mekić
20321d85465SGoran Mekić /* Most common values for samplerate (in kHz): 44.1, 48, 88.2, 96 */
20421d85465SGoran Mekić tmp = config->sample_rate;
20521d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_DSP_SPEED, &tmp);
20621d85465SGoran Mekić check_error(error, "SNDCTL_DSP_SPEED");
20721d85465SGoran Mekić
20821d85465SGoran Mekić /* Get and check device capabilities */
20921d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_DSP_GETCAPS, &(config->audio_info.caps));
21021d85465SGoran Mekić check_error(error, "SNDCTL_DSP_GETCAPS");
21121d85465SGoran Mekić if (!(config->audio_info.caps & PCM_CAP_DUPLEX)) {
21221d85465SGoran Mekić fprintf(stderr, "Device doesn't support full duplex!\n");
21321d85465SGoran Mekić exit(1);
21421d85465SGoran Mekić }
21521d85465SGoran Mekić if (config->mmap) {
21621d85465SGoran Mekić if (!(config->audio_info.caps & PCM_CAP_TRIGGER)) {
21721d85465SGoran Mekić fprintf(stderr, "Device doesn't support triggering!\n");
21821d85465SGoran Mekić exit(1);
21921d85465SGoran Mekić }
22021d85465SGoran Mekić if (!(config->audio_info.caps & PCM_CAP_MMAP)) {
22121d85465SGoran Mekić fprintf(stderr, "Device doesn't support mmap mode!\n");
22221d85465SGoran Mekić exit(1);
22321d85465SGoran Mekić }
22421d85465SGoran Mekić }
22521d85465SGoran Mekić
22621d85465SGoran Mekić /*
22721d85465SGoran Mekić * If desired frag is smaller than minimum, based on number of channels
22821d85465SGoran Mekić * and format (size in bits: 8, 16, 24, 32), set that as frag. Buffer size
22921d85465SGoran Mekić * is 2^frag, but the real size of the buffer will be read when the
230ee40f9e8SYuZhong-Chen * configuration of the device is successful
23121d85465SGoran Mekić */
23221d85465SGoran Mekić int min_frag = size2frag(config->sample_size * config->channels);
23321d85465SGoran Mekić
23421d85465SGoran Mekić if (config->frag < min_frag) {
23521d85465SGoran Mekić config->frag = min_frag;
23621d85465SGoran Mekić }
23721d85465SGoran Mekić
23821d85465SGoran Mekić /*
23921d85465SGoran Mekić * Allocate buffer in fragments. Total buffer will be split in number
24021d85465SGoran Mekić * of fragments (2 by default)
24121d85465SGoran Mekić */
24221d85465SGoran Mekić if (config->buffer_info.fragments < 0) {
24321d85465SGoran Mekić config->buffer_info.fragments = 2;
24421d85465SGoran Mekić }
24521d85465SGoran Mekić tmp = ((config->buffer_info.fragments) << 16) | config->frag;
24621d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_DSP_SETFRAGMENT, &tmp);
24721d85465SGoran Mekić check_error(error, "SNDCTL_DSP_SETFRAGMENT");
24821d85465SGoran Mekić
24921d85465SGoran Mekić /* When all is set and ready to go, get the size of buffer */
25021d85465SGoran Mekić error = ioctl(config->fd, SNDCTL_DSP_GETOSPACE, &(config->buffer_info));
25121d85465SGoran Mekić check_error(error, "SNDCTL_DSP_GETOSPACE");
25221d85465SGoran Mekić if (config->buffer_info.bytes < 1) {
25321d85465SGoran Mekić fprintf(
25421d85465SGoran Mekić stderr,
25521d85465SGoran Mekić "OSS buffer error: buffer size can not be %d\n",
25621d85465SGoran Mekić config->buffer_info.bytes
25721d85465SGoran Mekić );
25821d85465SGoran Mekić exit(1);
25921d85465SGoran Mekić }
26021d85465SGoran Mekić config->sample_count = config->buffer_info.bytes / config->sample_size;
26121d85465SGoran Mekić config->chsamples = config->sample_count / config->channels;
26221d85465SGoran Mekić }
263