Differential D30149 Diff 90254 share/examples/sound/ossinit.h

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share/examples/sound/ossinit.h

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				/*
				* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
				hselaskyUnsubmitted Done Inline Actions Please add a regular 2-clause BSD license here. hselasky: Please add a regular 2-clause BSD license here.
				*
				* Copyright (c) 2021 Goran Mekić
				*
				* Redistribution and use in source and binary forms, with or without
				* modification, are permitted provided that the following conditions
				pstefUnsubmitted Done Inline Actions style nit: as per style(9), "Kernel include files (sys/.h) come first" pstef:* style nit: as per style(9), "Kernel include files (sys/*.h) come first"
				* are met:
				* 1. Redistributions of source code must retain the above copyright
				* notice, this list of conditions and the following disclaimer.
				* 2. Redistributions in binary form must reproduce the above copyright
				* notice, this list of conditions and the following disclaimer in the
				* documentation and/or other materials provided with the distribution.
				*
				* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
				* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
				* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
				* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
				* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
				* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
				* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
				* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
				* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
				* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
				* SUCH DAMAGE.
				*/

				#include <sys/soundcard.h>
				#include <errno.h>
				#include <fcntl.h>
				#include <stdio.h>
				#include <stdlib.h>
				#include <string.h>
				#include <unistd.h>


				#ifndef SAMPLE_SIZE
				#define SAMPLE_SIZE 16
				#endif

				/* Format can be unsigned, in which case replace S with U */
				#if SAMPLE_SIZE == 32
				typedef int32_t sample_t;
				int format = AFMT_S32_NE; /* Signed 32bit native endian format */
				#elif SAMPLE_SIZE == 16
				typedef int16_t sample_t;
				int format = AFMT_S16_NE; /* Signed 16bit native endian format */
				#elif SAMPLE_SIZE == 8
				typedef int8_t sample_t;
				int format = AFMT_S8_NE; /* Signed 8bit native endian format */
				#else
				#error Unsupported sample format!
				typedef int32_t sample_t;
				int format = AFMT_S32_NE; /* Not a real value, just silencing
				* compiler errors */
				#endif



				hselaskyUnsubmitted Done Inline Actions C-functions in header files should read: static inline .... hselasky: C-functions in header files should read: static inline ....
				/*
				* Minimal configuration for OSS
				* For real world applications, this structure will probably contain many
				* more fields
				*/
				typedef struct config {
				char *device;
				int channels;
				int fd;
				int format;
				int frag;
				int sample_count;
				int sample_rate;
				int sample_size;
				int chsamples;
				int mmap;
				oss_audioinfo audio_info;
				audio_buf_info buffer_info;
				} config_t;


				/*
				* Error state is indicated by value=-1 in which case application exits
				* with error
				*/
				static inline void
				check_error(const int value, const char *message)
				{
				if (value == -1) {
				fprintf(stderr, "OSS error: %s %s\n", message, strerror(errno));
				exit(1);
				}
				}



				/* Calculate frag by giving it minimal size of buffer */
				static inline int
				size2frag(int x)
				{
				int frag = 0;

				while ((1 << frag) < x) {
				++frag;
				}
				return frag;
				}


				/*
				* Split input buffer into channels. Input buffer is in interleaved format
				* which means if we have 2 channels (L and R), this is what the buffer of
				* 8 samples would contain: L,R,L,R,L,R,L,R. The result are two channels
				* containing: L,L,L,L and R,R,R,R.
				*/
				void
				oss_split(config_t config, sample_t input, sample_t *output)
				{
				int channel;
				int index;

				for (int i = 0; i < config->sample_count; ++i) {
				channel = i % config->channels;
				index = i / config->channels;
				output[channel * index] = input[i];
				}
				}


				/*
				* Convert channels into interleaved format and place it in output
				* buffer
				*/
				void
				oss_merge(config_t config, sample_t input, sample_t *output)
				{
				for (int channel = 0; channel < config->channels; ++channel) {
				for (int index = 0; index < config->chsamples; ++index) {
				output[index * config->channels + channel] = input[channel * index];
				}
				}
				}

				void
				oss_init(config_t *config)
				{
				int error;
				int tmp;

				/* Open the device for read and write */
				config->fd = open(config->device, O_RDWR);
				check_error(config->fd, "open");

				/* Get device information */
				config->audio_info.dev = -1;
				error = ioctl(config->fd, SNDCTL_ENGINEINFO, &(config->audio_info));
				check_error(error, "SNDCTL_ENGINEINFO");
				printf("min_channels: %d\n", config->audio_info.min_channels);
				printf("max_channels: %d\n", config->audio_info.max_channels);
				printf("latency: %d\n", config->audio_info.latency);
				printf("handle: %s\n", config->audio_info.handle);
				if (config->audio_info.min_rate > config->sample_rate \|\| config->sample_rate > config->audio_info.max_rate) {
				fprintf(stderr, "%s doesn't support chosen ", config->device);
				fprintf(stderr, "samplerate of %dHz!\n", config->sample_rate);
				exit(1);
				}
				if (config->channels < 1) {
				config->channels = config->audio_info.max_channels;
				}

				/*
				* If device is going to be used in mmap mode, disable all format
				* conversions. Official OSS documentation states error code should not be
				* checked. http://manuals.opensound.com/developer/mmap_test.c.html#LOC10
				*/
				if (config->mmap) {
				tmp = 0;
				ioctl(config->fd, SNDCTL_DSP_COOKEDMODE, &tmp);
				}

				/*
				* Set number of channels. If number of channels is chosen to the value
				* near the one wanted, save it in config
				*/
				tmp = config->channels;
				error = ioctl(config->fd, SNDCTL_DSP_CHANNELS, &tmp);
				check_error(error, "SNDCTL_DSP_CHANNELS");
				if (tmp != config->channels) { /* or check if tmp is close enough? */
				fprintf(stderr, "%s doesn't support chosen ", config->device);
				fprintf(stderr, "channel count of %d", config->channels);
				fprintf(stderr, ", set to %d!\n", tmp);
				}
				config->channels = tmp;

				/* Set format, or bit size: 8, 16, 24 or 32 bit sample */
				tmp = config->format;
				error = ioctl(config->fd, SNDCTL_DSP_SETFMT, &tmp);
				check_error(error, "SNDCTL_DSP_SETFMT");
				if (tmp != config->format) {
				fprintf(stderr, "%s doesn't support chosen sample format!\n", config->device);
				exit(1);
				}

				/* Most common values for samplerate (in kHz): 44.1, 48, 88.2, 96 */
				tmp = config->sample_rate;
				error = ioctl(config->fd, SNDCTL_DSP_SPEED, &tmp);
				check_error(error, "SNDCTL_DSP_SPEED");

				/* Get and check device capabilities */
				error = ioctl(config->fd, SNDCTL_DSP_GETCAPS, &(config->audio_info.caps));
				check_error(error, "SNDCTL_DSP_GETCAPS");
				if (!(config->audio_info.caps & PCM_CAP_DUPLEX)) {
				fprintf(stderr, "Device doesn't support full duplex!\n");
				exit(1);
				}
				if (config->mmap) {
				if (!(config->audio_info.caps & PCM_CAP_TRIGGER)) {
				fprintf(stderr, "Device doesn't support triggering!\n");
				exit(1);
				}
				if (!(config->audio_info.caps & PCM_CAP_MMAP)) {
				fprintf(stderr, "Device doesn't support mmap mode!\n");
				exit(1);
				}
				}

				/*
				* If desired frag is smaller than minimum, based on number of channels
				* and format (size in bits: 8, 16, 24, 32), set that as frag. Buffer size
				* is 2^frag, but the real size of the buffer will be read when the
				* configuration of the device is successfull
				*/
				int min_frag = size2frag(config->sample_size * config->channels);

				if (config->frag < min_frag) {
				config->frag = min_frag;
				}

				/*
				* Allocate buffer in fragments. Total buffer will be split in number
				* of fragments (2 by default)
				*/
				if (config->buffer_info.fragments < 0) {
				config->buffer_info.fragments = 2;
				}
				tmp = ((config->buffer_info.fragments) << 16) \| config->frag;
				error = ioctl(config->fd, SNDCTL_DSP_SETFRAGMENT, &tmp);
				check_error(error, "SNDCTL_DSP_SETFRAGMENT");

				/* When all is set and ready to go, get the size of buffer */
				error = ioctl(config->fd, SNDCTL_DSP_GETOSPACE, &(config->buffer_info));
				check_error(error, "SNDCTL_DSP_GETOSPACE");
				if (config->buffer_info.bytes < 1) {
				fprintf(
				stderr,
				"OSS buffer error: buffer size can not be %d\n",
				config->buffer_info.bytes
				);
				exit(1);
				}
				config->sample_count = config->buffer_info.bytes / config->sample_size;
				config->chsamples = config->sample_count / config->channels;
				}