flycast/core/audio/audiobackend_oss.cpp

152 lines
2.7 KiB
C++

#ifdef USE_OSS
#include "audiostream.h"
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/soundcard.h>
#include <unistd.h>
class OSSAudioBackend : public AudioBackend
{
int audioFD = -1;
int recordFD = -1;
static int openDevice(int flags)
{
const char* path = "/dev/dsp";
int fd = open(path, flags);
if (fd < 0)
ERROR_LOG(AUDIO, "OSS: open(%s) failed: %s", path, strerror(errno));
return fd;
}
static bool setRate(int fd, int rate)
{
int tmp = rate;
if (ioctl(fd, SNDCTL_DSP_SPEED, &tmp) < 0)
{
ERROR_LOG(AUDIO, "OSS: ioctl(SNDCTL_DSP_SPEED) failed: %s", strerror(errno));
return false;
}
if (tmp != rate)
{
ERROR_LOG(AUDIO, "OSS: sample rate unsupported: %d => %d", rate, tmp);
return false;
}
return true;
}
static bool setChannels(int fd, int channels)
{
int tmp = channels;
if (ioctl(fd, SNDCTL_DSP_CHANNELS, &tmp) < 0)
{
ERROR_LOG(AUDIO, "OSS: ioctl(SNDCTL_DSP_CHANNELS) failed: %s", strerror(errno));
return false;
}
if (tmp != channels)
{
ERROR_LOG(AUDIO, "OSS: channels unsupported: %d => %d", channels, tmp);
return false;
}
return true;
}
static bool setFormat(int fd, int format)
{
int tmp = format;
if (ioctl(fd, SNDCTL_DSP_SETFMT, &tmp) < 0)
{
ERROR_LOG(AUDIO, "OSS: ioctl(SNDCTL_DSP_SETFMT) failed: %s", strerror(errno));
return false;
}
if (tmp != format)
{
ERROR_LOG(AUDIO, "OSS: sample format unsupported: %#.8x => %#.8x", format, tmp);
return false;
}
return true;
}
public:
OSSAudioBackend()
: AudioBackend("oss", "Open Sound System") {}
bool init() override
{
audioFD = openDevice(O_WRONLY);
if (audioFD < 0 || !setRate(audioFD, 44100) || !setChannels(audioFD, 2) || !setFormat(audioFD, AFMT_S16_LE))
{
term();
return false;
}
return true;
}
u32 push(const void* frame, u32 samples, bool wait) override
{
write(audioFD, frame, samples * 4);
return 1;
}
void term() override
{
if (audioFD >= 0)
close(audioFD);
audioFD = -1;
}
// recording untested
bool initRecord(u32 sampling_freq) override
{
recordFD = openDevice(O_RDONLY);
if (recordFD < 0 || !setRate(recordFD, sampling_freq) || !setChannels(recordFD, 1) || !setFormat(recordFD, AFMT_S16_NE /* Native 16 bits */ ))
{
termRecord();
return false;
}
return true;
}
void termRecord() override
{
if (recordFD >= 0)
close(recordFD);
recordFD = -1;
}
u32 record(void *buffer, u32 samples) override
{
samples *= 2;
int l = read(recordFD, buffer, samples);
if (l < (int)samples)
{
if (l < 0)
{
INFO_LOG(AUDIO, "OSS: Recording error");
l = 0;
}
memset((u8 *)buffer + l, 0, samples - l);
}
return l / 2;
}
};
static OSSAudioBackend ossAudioBackend;
#endif