Tasmota/lib/lib_audio/ESP8266Audio/examples/StreamOnHost/AudioOutputLinuxDSP.h

119 lines
3.3 KiB
C++

/*
AudioOutput
Base class of an audio output player
Copyright (C) 2017 Earle F. Philhower, III
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _AUDIOOUTPUTNULLSLOW_H
#define _AUDIOOUTPUTNULLSLOW_H
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <stdio.h>
#include <linux/soundcard.h>
#include "AudioOutput.h"
class AudioOutputNullSlow : public AudioOutput
{
public:
AudioOutputNullSlow() { };
~AudioOutputNullSlow() {};
virtual bool begin() { samples = 0; startms = millis(); return true; }
virtual bool ConsumeSample(int16_t sample[2]) {
if (fd < 0) {
fd = open("/dev/dsp", O_RDWR);
if (fd < 0) {
perror("open of /dev/dsp failed (Try with 'padsp this-exec')");
exit(1);
}
}
if (channels && lastchannels != channels) {
Serial.printf("CHANNELS=%d\n", channels);
int arg = channels; /* mono or stereo */
int status = ioctl(fd, SOUND_PCM_WRITE_CHANNELS, &arg);
if (status == -1) {
perror("SOUND_PCM_WRITE_CHANNELS ioctl failed");
exit(1);
} else if (arg != channels) {
perror("unable to set number of channels");
exit(1);
}
lastchannels = channels;
}
if (lastchannels > 0 && hertz && lasthertz != hertz) {
Serial.printf("FREQ=%d\n", hertz);
int arg = hertz*4/lastchannels; /* sampling rate */
int status = ioctl(fd, SOUND_PCM_WRITE_RATE, &arg);
if (status == -1) {
perror("SOUND_PCM_WRITE_RATE ioctl failed");
exit(1);
}
lasthertz = hertz;
}
if (bps && lastbps != bps) {
Serial.printf("BPS=%d\n", bps);
int arg = bps; /* sample size */
int status = ioctl(fd, SOUND_PCM_WRITE_BITS, &arg);
if (status == -1) {
perror("SOUND_PCM_WRITE_BITS ioctl failed");
exit(1);
} else if (arg != bps) {
perror("unable to set sample size");
exit(1);
}
lastbps = bps;
}
if ((++samples & ((1<<9)-1)) == 0) {
// let the main loop a chance to run
return false;
}
if (write(fd, sample, sizeof(sample)) != sizeof(sample)) {
perror("doing sound");
exit(1);
}
return true;
}
virtual bool stop() { endms = millis(); return true; };
unsigned long GetMilliseconds() { return endms - startms; }
int GetSamples() { return samples; }
int GetFrequency() { return hertz; }
protected:
unsigned long startms;
unsigned long endms;
int samples;
int lastchannels = -1;
int lasthertz = -1;
int lastbps = -1;
int fd = -1;
};
#endif