public static unsafe void StartMixer(int sampleRate, short bufferLen)
{
SDL_AudioSpec desired = new SDL_AudioSpec();
m_ObtainedSpecs = new SDL_AudioSpec();
desired.channels = 1;
desired.format = Sdl.AUDIO_U8;
desired.freq = sampleRate;
desired.samples = bufferLen;
desired.callback = audioCallback;
IntPtr desiredPtr = Marshal.AllocHGlobal(Marshal.SizeOf(desired));
IntPtr obtainedPtr = Marshal.AllocHGlobal(Marshal.SizeOf(m_ObtainedSpecs));
try
{
Marshal.StructureToPtr(desired, desiredPtr, false);
int i = Sdl.SDL_OpenAudio(desiredPtr, obtainedPtr);
m_ObtainedSpecs = (SDL_AudioSpec)Marshal.PtrToStructure(obtainedPtr, typeof(SDL_AudioSpec));
}
finally
{
Marshal.FreeHGlobal(desiredPtr);
Marshal.FreeHGlobal(obtainedPtr);
}
m_SampleRate = m_ObtainedSpecs.freq;
m_BaseLine = (byte)m_ObtainedSpecs.silence;
Sdl.SDL_PauseAudio(0);
}
public AudioContext(int freq, ushort format, byte channels)
{
AudioSpec = new SDL_AudioSpec()
{
freq = freq,
format = format,
channels = channels,
samples = (ushort)MinBufferSize,
};
switch (format)
{
case AUDIO_U8: {
BytesPerSample = 1;
} break;
case AUDIO_S16LSB: {
BytesPerSample = 2;
} break;
}
;
DeviceId = SDL_OpenAudioDevice(null, 0, ref AudioSpec, out AudioSpec, 0);
if (DeviceId == 0)
{
throw new Exception(SDL_GetError());
}
SDL_PauseAudioDevice(DeviceId, 0);
}
static void Test()
{
SF2 sf2 = new SF2("g:\\test.sf2");
List <short> samples = sf2.SoundChunk.SMPLSubChunk.samples;
PCMProcesser pcmProcesser = new PCMProcesser();
short[] newSamples = pcmProcesser.PitchPcmNote(samples.ToArray(), 24);
// pitch.Seq(samples.ToArray());
pcm_buffer = new byte[newSamples.Length * 2];
int idx = 0;
for (int i = 0; i < newSamples.Length; i++)
{
pcm_buffer[idx++] = (byte)(newSamples[i] & 0xff);
pcm_buffer[idx++] = (byte)((newSamples[i] >> 8) & 0xff);
}
float newTime = pcmProcesser.GetPcmTime(newSamples, 44100);
SDL_AudioSpec OutputAudioSpec = new SDL_AudioSpec();
OutputAudioSpec.freq = 44100;
OutputAudioSpec.format = AUDIO_S16;
OutputAudioSpec.channels = 1;
OutputAudioSpec.samples = 1024;
OutputAudioSpec.callback = SDL_AudioCallback;
if (SDL_AudioInit(null) < 0)
{
return;
}
IntPtr n = IntPtr.Zero;
if (SDL_OpenAudio(ref OutputAudioSpec, n) < 0)
{
return;
}
audio_len = pcm_buffer.Length; //长度为读出数据长度，在read_audio_data中做减法
audio_pos = pcm_buffer;
audio_idx = 0;
SDL_PauseAudio(0);
SDL_Delay((uint)(Math.Round(newTime) * 1000));
}
private void InitialiseAudio(int sampleRate)
{
DisposeAudio();
var want = new SDL_AudioSpec
{
freq = sampleRate,
format = AUDIO_S16,
channels = 2
};
_audioDevice = SDL_OpenAudioDevice(null, 0, ref want, out var have, 0);
SDL_PauseAudioDevice(_audioDevice, 0);
}
int ISoundPcmDriver.Initialize(int freq, int format)
{
int result = 0;
this.sdlCallback = new SDL_AudioCallback(this.SdlCallback);
SDL_AudioSpec desired = new SDL_AudioSpec
{
freq = freq,
format = (ushort)format,
samples = SAMPLESIZE,
channels = 1,
userdata = IntPtr.Zero,
callback = this.sdlCallback,
};
SDL_AudioSpec obtained = default(SDL_AudioSpec);
//IntPtr desiredPtr = Marshal.AllocHGlobal(Marshal.SizeOf(desired));
IntPtr obtainedPtr = Marshal.AllocHGlobal(Marshal.SizeOf(obtained));
try
{
//Marshal.StructureToPtr(desired, desiredPtr, false);
result = SDL_OpenAudio(ref desired, obtainedPtr);
if (result == 0)
{
obtained = (SDL_AudioSpec)Marshal.PtrToStructure(obtainedPtr, typeof(SDL_AudioSpec));
// pauses callback
(this as ISoundPcmDriver).SetState(false);
}
else
{
Trace.WriteLine("pcthis.out_sdl_init(): unable to open audio.");
}
}
finally
{
//Marshal.FreeHGlobal(desiredPtr);
Marshal.FreeHGlobal(obtainedPtr);
}
return(result);
}
private static extern IntPtr SDL_LoadWAV_RW(IntPtr source, int freeSource, ref SDL_AudioSpec specs, out IntPtr buffer, out uint length);
public extern static SDL_AudioSpec SDL_LoadWAV_RW( SDL_RWops src,
int freesrc,
SDL_AudioSpec spec,
byte[] audio_buf,
out uint audio_len);
public static extern uint SDL_OpenAudioDevice([In()][MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(SDLMarshaler))] string device, int iscapture, ref SDL_AudioSpec desired, out SDL_AudioSpec obtained, int allowed_change);
public static extern uint SDL_OpenAudioDevice( [InAttribute()] [MarshalAsAttribute(UnmanagedType.LPStr)] string device, int iscapture, ref SDL_AudioSpec desired, ref SDL_AudioSpec obtained, int allowed_changes );
public extern static int SDL_OpenAudio(SDL_AudioSpec desired, out SDL_AudioSpec obtained);
public static IntPtr SDL_LoadWAV_RW(IntPtr src, int freesrc, ref SDL_AudioSpec spec, IntPtr audio_buf, ref uint audio_len) => s_SDL_LoadWAV_RW_SDL_RWops_int_SDL_AudioSpec_IntPtr_uint_t(src, freesrc, ref spec, audio_buf, ref audio_len);
public static int SDL_OpenAudio(ref SDL_AudioSpec desired, ref SDL_AudioSpec obtained) => s_SDL_OpenAudio_SDL_AudioSpec_SDL_AudioSpec_t(ref desired, ref obtained);
private static IntPtr SDL_LoadWAV_RW(string filename, int freeSource, ref SDL_AudioSpec specs, out IntPtr buffer, out uint length) => SDL_LoadWAV_RW(SDL_RWFromFile(filename.ToBytes(), "rb".ToBytes()), freeSource, ref specs, out buffer, out length);
public static bool LoadWAV(string fileName, out byte[] pcm, out SDL_AudioSpec spec)
{
pcm = new byte[0];
spec = new SDL_AudioSpec();
byte[] bytes = File.ReadAllBytes(fileName);
int pointer = 0;
WaveHeader header = bytes.Consume <WaveHeader>(ref pointer);
if (header.RiffId != WaveId_RIFF)
{
return(false);
}
if (header.WaveId != WaveId_WAVE)
{
return(false);
}
while (pointer < bytes.Length)
{
WaveChunkHeader chunkHeader = bytes.Consume <WaveChunkHeader>(ref pointer);
if (chunkHeader.Id == WaveId_fmt)
{
WaveFmt fmt = bytes.ReadStruct <WaveFmt>(pointer);
spec = new SDL_AudioSpec()
{
freq = (int)fmt.SampleRate,
channels = (byte)fmt.Channels,
};
if (fmt.FormatTag != 1)
{
return(false);
}
switch (fmt.BitsPerSample)
{
case 8: {
spec.format = AUDIO_U8;
} break;
case 16: {
spec.format = AUDIO_S16LSB;
} break;
}
;
}
else if (chunkHeader.Id == WaveId_data)
{
pcm = bytes.Subarray(pointer, (int)chunkHeader.Size);
}
pointer += (int)chunkHeader.Size;
}
if (spec.format == AUDIO_U8)
{
byte[] newPCM = new byte[pcm.Length * 2];
for (int i = 0; i < pcm.Length; i++)
{
short sample16 = (short)((pcm[i] - 0x80) << 8);
newPCM[i * 2 + 0] = (byte)(sample16 & 0xFF);
newPCM[i * 2 + 1] = (byte)(sample16 >> 8);
}
pcm = newPCM;
spec.format = AUDIO_S16LSB;
}
return(true);
}
/// <summary>
/// SDs the l_ load WA.
/// </summary>
/// <returns>
/// The l_ load WA.
/// </returns>
/// <param name='file'>
/// File.
/// </param>
/// <param name='spec'>
/// Spec.
/// </param>
/// <param name='audio_buf'>
/// Audio_buf.
/// </param>
/// <param name='audio_len'>
/// Audio_len.
/// </param>
public static SDL_AudioSpec SDL_LoadWAV(string file, SDL_AudioSpec spec, byte[] audio_buf, out uint audio_len)
{
return(SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"), 1, spec, audio_buf, out audio_len));
}
public extern static SDL_AudioSpec SDL_LoadWAV_RW(SDL_RWops src,
int freesrc,
SDL_AudioSpec spec,
byte[] audio_buf,
out uint audio_len);
public extern static int SDL_OpenAudio(SDL_AudioSpec desired, out SDL_AudioSpec obtained);
/// <summary>
/// SDs the l_ load WA.
/// </summary>
/// <returns>
/// The l_ load WA.
/// </returns>
/// <param name='file'>
/// File.
/// </param>
/// <param name='spec'>
/// Spec.
/// </param>
/// <param name='audio_buf'>
/// Audio_buf.
/// </param>
/// <param name='audio_len'>
/// Audio_len.
/// </param>
public static SDL_AudioSpec SDL_LoadWAV(string file, SDL_AudioSpec spec, byte[] audio_buf, out uint audio_len) {
return SDL_LoadWAV_RW( SDL_RWFromFile( file, "rb" ), 1, spec, audio_buf, out audio_len );
}
private static extern int SDL_OpenAudio(ref SDL_AudioSpec desired, out SDL_AudioSpec obtained);
private static extern IntPtr INTERNAL_SDL_LoadWAV( [InAttribute()] [MarshalAsAttribute(UnmanagedType.LPStr)] string filename, ref SDL_AudioSpec spec, ref IntPtr audio_buf, ref uint audio_len );
public static SDL_AudioDeviceID SDL_OpenAudioDevice(IntPtr device, int iscapture, ref
SDL_AudioSpec desired, ref SDL_AudioSpec obtained, int
allowed_changes) => s_SDL_OpenAudioDevice_IntPtr_int_SDL_AudioSpec_SDL_AudioSpec_int_t(device, iscapture, ref desired, ref obtained, allowed_changes);
public static SDL_AudioSpec SDL_LoadWAV(
string filename,
ref SDL_AudioSpec spec,
ref IntPtr audio_buf,
ref uint audio_len
) {
SDL_AudioSpec result;
IntPtr result_ptr = INTERNAL_SDL_LoadWAV(
filename,
ref spec,
ref audio_buf,
ref audio_len
);
result = (SDL_AudioSpec) Marshal.PtrToStructure(
result_ptr,
result.GetType()
);
return result;
}
public static extern SDL_AudioSpec *SDL_LoadWAV_RW(
RWOps src,
int freesrc,
out SDL_AudioSpec spec,
out byte *audio_buf,
out uint audio_len);
public static extern int SDL_OpenAudio( ref SDL_AudioSpec desired, ref SDL_AudioSpec obtained );
