126 lines
3.5 KiB
C
126 lines
3.5 KiB
C
/*
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* Simple sound playback using ALSA API and libasound.
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*
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* Compile:
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* $ cc -o play sound_playback.c -lasound
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*
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* Usage:
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* $ ./play <sample_rate> <channels> <seconds> < <file>
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*
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* Examples:
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* $ ./play 44100 2 5 < /dev/urandom
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* $ ./play 22050 1 8 < /path/to/file.wav
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*
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* Copyright (C) 2009 Alessandro Ghedini <alessandro@ghedini.me>
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* --------------------------------------------------------------
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* "THE BEER-WARE LICENSE" (Revision 42):
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* Alessandro Ghedini wrote this file. As long as you retain this
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* notice you can do whatever you want with this stuff. If we
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* meet some day, and you think this stuff is worth it, you can
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* buy me a beer in return.
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* --------------------------------------------------------------
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*/
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#include <alsa/asoundlib.h>
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#include <stdio.h>
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#define PCM_DEVICE "default"
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int main(int argc, char **argv) {
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unsigned int pcm, tmp, dir;
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int rate, channels, seconds;
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snd_pcm_t *pcm_handle;
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snd_pcm_hw_params_t *params;
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snd_pcm_uframes_t frames;
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char *buff;
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int buff_size, loops;
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if (argc < 4) {
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printf("Usage: %s <sample_rate> <channels> <seconds>\n",
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argv[0]);
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return -1;
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}
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rate = atoi(argv[1]);
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channels = atoi(argv[2]);
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seconds = atoi(argv[3]);
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/* Open the PCM device in playback mode */
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if (pcm = snd_pcm_open(&pcm_handle, PCM_DEVICE,
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SND_PCM_STREAM_PLAYBACK, 0) < 0)
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printf("ERROR: Can't open \"%s\" PCM device. %s\n",
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PCM_DEVICE, snd_strerror(pcm));
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/* Allocate parameters object and fill it with default values*/
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snd_pcm_hw_params_alloca(¶ms);
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snd_pcm_hw_params_any(pcm_handle, params);
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/* Set parameters */
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if (pcm = snd_pcm_hw_params_set_access(pcm_handle, params,
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SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
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printf("ERROR: Can't set interleaved mode. %s\n", snd_strerror(pcm));
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if (pcm = snd_pcm_hw_params_set_format(pcm_handle, params,
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SND_PCM_FORMAT_S16_LE) < 0)
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printf("ERROR: Can't set format. %s\n", snd_strerror(pcm));
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if (pcm = snd_pcm_hw_params_set_channels(pcm_handle, params, channels) < 0)
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printf("ERROR: Can't set channels number. %s\n", snd_strerror(pcm));
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if (pcm = snd_pcm_hw_params_set_rate_near(pcm_handle, params, &rate, 0) < 0)
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printf("ERROR: Can't set rate. %s\n", snd_strerror(pcm));
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/* Write parameters */
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if (pcm = snd_pcm_hw_params(pcm_handle, params) < 0)
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printf("ERROR: Can't set harware parameters. %s\n", snd_strerror(pcm));
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/* Resume information */
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printf("PCM name: '%s'\n", snd_pcm_name(pcm_handle));
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printf("PCM state: %s\n", snd_pcm_state_name(snd_pcm_state(pcm_handle)));
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snd_pcm_hw_params_get_channels(params, &tmp);
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printf("channels: %i ", tmp);
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if (tmp == 1)
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printf("(mono)\n");
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else if (tmp == 2)
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printf("(stereo)\n");
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snd_pcm_hw_params_get_rate(params, &tmp, 0);
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printf("rate: %d bps\n", tmp);
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printf("seconds: %d\n", seconds);
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/* Allocate buffer to hold single period */
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snd_pcm_hw_params_get_period_size(params, &frames, 0);
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buff_size = frames * channels * 2 /* 2 -> sample size */;
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buff = (char *) malloc(buff_size);
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snd_pcm_hw_params_get_period_time(params, &tmp, NULL);
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for (loops = (seconds * 1000000) / tmp; loops > 0; loops--) {
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if (pcm = read(0, buff, buff_size) == 0) {
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printf("Early end of file.\n");
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return 0;
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}
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if (pcm = snd_pcm_writei(pcm_handle, buff, frames) == -EPIPE) {
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printf("XRUN.\n");
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snd_pcm_prepare(pcm_handle);
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} else if (pcm < 0) {
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printf("ERROR. Can't write to PCM device. %s\n", snd_strerror(pcm));
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}
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}
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snd_pcm_drain(pcm_handle);
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snd_pcm_close(pcm_handle);
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free(buff);
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return 0;
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}
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