public void Start()
{
_firstAfterStart = true;
if (_soundPcm != null)
{
_soundPcm.Dispose();
}
_soundPcm = new SoundPcm("default", snd_pcm_stream_t.SND_PCM_STREAM_CAPTURE, 0);
using (var hardwareParams = new SoundPcmHardwareParams(_soundPcm))
{
hardwareParams.Any();
hardwareParams.Access = snd_pcm_access_t.SND_PCM_ACCESS_RW_INTERLEAVED;
hardwareParams.Format = snd_pcm_format_t.SND_PCM_FORMAT_S16_LE;
uint rate = 8000;
int dir = 0;
hardwareParams.SetRateNear(ref rate, ref dir);
if (rate != 8000)
{
throw new Exception($"Could not get required sample rate of {8000} instead got {rate}");
}
hardwareParams.Channels = 1;
uint periodSize = 160;
hardwareParams.SetPeriodSizeNear(ref periodSize, ref dir);
if (periodSize != 160)
{
Console.WriteLine($"Requested Alsa PeriodSize 160 but got {periodSize}");
}
uint periods = 2;
hardwareParams.SetPeriodsNear(ref periods, ref dir);
if (periods != 2)
{
Console.WriteLine($"Requested Alsa Periods 2 but got {periods}");
}
_soundPcm.HardwareParams = hardwareParams;
_soundPcm.Prepare(); //this starts filling the buffer so need top Drop
_soundPcm.Start();
}
}
public AlsaAudioPlayer(bool prefillBuffer)
{
_prefillBuffer = prefillBuffer;
_soundPcm = new SoundPcm("default", snd_pcm_stream_t.SND_PCM_STREAM_PLAYBACK, 0);
using (var hardwareParams = new SoundPcmHardwareParams(_soundPcm))
{
hardwareParams.Any();
hardwareParams.Access = snd_pcm_access_t.SND_PCM_ACCESS_RW_INTERLEAVED;
hardwareParams.Format = snd_pcm_format_t.SND_PCM_FORMAT_S16_LE;
uint rate = 8000;
int dir = 0;
hardwareParams.SetRateNear(ref rate, ref dir);
if (rate != 8000)
{
throw new Exception($"AlsaAudioPlayer: Could not get required sample rate of {8000} instead got {rate}");
}
hardwareParams.Channels = 1;
uint periodSize = 160;
hardwareParams.SetPeriodSizeNear(ref periodSize, ref dir);
if (periodSize != 160)
{
Console.WriteLine($"Requested Alsa PeriodSize 160 but got {periodSize}");
}
uint periods = 2;
hardwareParams.SetPeriodsNear(ref periods, ref dir);
if (periods != 2)
{
Console.WriteLine($"AlsaAudioPlayer: Could not get required periods {2} instead got {periods}");
}
_periods = periods;
uint bufferSize = 320;
hardwareParams.SetBufferNear(ref bufferSize);
if (bufferSize != 320)
{
Console.WriteLine($"AlsaAudioPlayer: Could not get requested buffer size instead got {bufferSize}");
}
_soundPcm.HardwareParams = hardwareParams;
}
}
