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#if NET_2_0
using System;
using System.IO;
using System.Runtime.InteropServices;
namespace Mono.Audio {
/* these are the values used by alsa */
#if PUBLIC_API
public
#else
internal
#endif
enum AudioFormat {
S8,
U8,
S16_LE,
S16_BE,
U16_LE,
U16_BE,
S24_LE,
S24_BE,
U24_LE,
U24_BE,
S32_LE,
S32_BE,
U32_LE,
U32_BE,
FLOAT_LE,
FLOAT_BE,
FLOAT64_LE,
FLOAT64_BE,
IEC958_SUBFRAME_LE,
IEC958_SUBFRAME_BE,
MU_LAW,
A_LAW,
IMA_ADPCM,
MPEG,
GSM
}
#if PUBLIC_API
public
#else
internal
#endif
class AudioDevice {
static AudioDevice TryAlsa (string name) {
AudioDevice dev;
try {
dev = new AlsaDevice (name);
return dev;
} catch {
return null;
}
}
public static AudioDevice CreateDevice (string name) {
AudioDevice dev;
dev = TryAlsa (name);
/* if no option is found, return a silent device */
if (dev == null)
dev = new AudioDevice ();
return dev;
}
public virtual bool SetFormat (AudioFormat format, int channels, int rate) {
return true;
}
public virtual int PlaySample (byte[] buffer, int num_frames) {
return num_frames;
}
public virtual void Wait () {
}
}
class AlsaDevice: AudioDevice, IDisposable {
IntPtr handle;
[DllImport ("libasound.so.2")]
static extern int snd_pcm_open (ref IntPtr handle, string pcm_name, int stream, int mode);
[DllImport ("libasound.so.2")]
static extern int snd_pcm_close (IntPtr handle);
[DllImport ("libasound.so.2")]
static extern int snd_pcm_drain (IntPtr handle);
[DllImport ("libasound.so.2")]
static extern int snd_pcm_writei (IntPtr handle, byte[] buf, int size);
[DllImport ("libasound.so.2")]
static extern int snd_pcm_set_params (IntPtr handle, int format, int access, int channels, int rate, int soft_resample, int latency);
public AlsaDevice (string name) {
if (name == null)
name = "default";
int err = snd_pcm_open (ref handle, name, 0, 0);
if (err < 0)
throw new Exception ("no open " + err);
}
~AlsaDevice () {
Dispose (false);
}
public void Dispose () {
Dispose (true);
GC.SuppressFinalize (this);
}
protected virtual void Dispose (bool disposing) {
if (disposing) {
}
if (handle != IntPtr.Zero)
snd_pcm_close (handle);
handle = IntPtr.Zero;
}
public override bool SetFormat (AudioFormat format, int channels, int rate) {
int err = snd_pcm_set_params (handle, (int)format, 3, channels, rate, 1, 500000);
return err == 0;
}
public override int PlaySample (byte[] buffer, int num_frames) {
int frames = snd_pcm_writei (handle, buffer, num_frames);
return frames;
}
public override void Wait () {
snd_pcm_drain (handle);
}
}
}
#endif
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