Golang SDL_AudioSpec.freq方法代碼示例

func OpenAudio(desired, obtained_orNil *AudioSpec) int {
	if alreadyOpened {
		panic("more than 1 audio stream currently not supported")
	}

	// copy handle to user-defined callback function, if defined
	// it is perfectly supported to not specify the callback function
	// in that case you will use default SendAudio semantics
	// note that if you specify a callback and use SendAudio, a hangup will instead happen
	// when calling SendAudio

	if nil != desired.UserDefinedCallback {
		userDefinedCallback = desired.UserDefinedCallback
	} else {
		// default playback (16-bit signed)
		userDefinedCallback = DownstreamPlaybackS16
		PlayLoop = make(chan AudioEvent)
	}

	var C_desired, C_obtained *C.SDL_AudioSpec

	C_desired = new(C.SDL_AudioSpec)
	C_desired.freq = C.int(desired.Freq)
	C_desired.format = C.Uint16(desired.Format)
	C_desired.channels = C.Uint8(desired.Channels)
	C_desired.samples = C.Uint16(desired.Samples)
	// there is an unique C callback acting as proxy to the different Go callbacks
	// see streamContext()
	C_desired.callback = C.callback_getCallback()

	if obtained_orNil != nil {
		if desired != obtained_orNil {
			C_obtained = new(C.SDL_AudioSpec)
		} else {
			C_obtained = C_desired
		}
	}

	status := C.SDL_OpenAudio(C_desired, C_obtained)

	if status == 0 {
		alreadyOpened = true
	}

	if obtained_orNil != nil {
		obtained := obtained_orNil

		obtained.Freq = int(C_obtained.freq)
		obtained.Format = uint16(C_obtained.format)
		obtained.Channels = uint8(C_obtained.channels)
		obtained.Samples = uint16(C_obtained.samples)
		obtained.Out_Silence = uint8(C_obtained.silence)
		obtained.Out_Size = uint32(C_obtained.size)
	}

	return int(status)
}

func initAudio() {
	var want C.SDL_AudioSpec
	want.freq = 44100
	want.format = C.AUDIO_S16LSB
	want.samples = 8096
	C.setCallback(&want)
	C.SDL_OpenAudio(&want, &openedSpec)
	C.SDL_PauseAudio(0)
}

func initAudio() {
	// Init a simple audio setup.
	var spec C.SDL_AudioSpec
	spec.freq = C.int(SamplingRate)
	spec.format = C.AUDIO_S8
	spec.channels = 1
	spec.samples = 512
	spec.userdata = nil
	C.openAudio(&spec)
}

func Init() {
	if ok := C.SDL_InitSubSystem(C.SDL_INIT_AUDIO); ok < 0 {
		panic(ok)
	}
	var want C.SDL_AudioSpec
	want.freq = 48000
	want.format = C.AUDIO_S16
	want.channels = 2
	want.callback = (C.SDL_AudioCallback)(unsafe.Pointer(C.audio_callback_go_cgo))
	var have C.SDL_AudioSpec
	if dev = C.SDL_OpenAudioDevice(nil, 0, &want, &have, 0); dev == 0 {
		panic("dev=0")
	}
}

func OpenAudio(desired, obtained *AudioSpec, callback func(*byte, int)) bool {
	var cdesired C.SDL_AudioSpec
	var cobtained C.SDL_AudioSpec
	cdesired.freq = C.int(desired.Freq)
	cdesired.format = C.SDL_AudioFormat(int(desired.Format))
	cdesired.channels = C.Uint8(desired.Channels)
	cdesired.samples = C.Uint16(desired.Samples)
	cdesired.size = C.Uint32(0)
	cdesired.callback = C.go_sdl2_get_callback()
	cdesired.userdata = unsafe.Pointer(&callback)
	ret := C.SDL_OpenAudio(&cdesired, &cobtained)
	if obtained != nil {
		obtained.Freq = int32(cobtained.freq)
		obtained.Format = AudioFormat(int(cobtained.format))
		obtained.Channels = uint8(cobtained.channels)
		obtained.Silence = uint8(cobtained.silence)
		obtained.Samples = uint16(cobtained.samples)
		obtained.Size = uint32(cobtained.size)
	}
	return int(ret) == 0
}

func OpenAudio(desired, obtained_orNil *AudioSpec) int {
	var C_desired, C_obtained *C.SDL_AudioSpec

	C_desired = new(C.SDL_AudioSpec)
	C_desired.freq = C.int(desired.Freq)
	C_desired.format = C.Uint16(desired.Format)
	C_desired.channels = C.Uint8(desired.Channels)
	C_desired.samples = C.Uint16(desired.Samples)
	C_desired.callback = C.callback_getCallback()

	if obtained_orNil != nil {
		if desired != obtained_orNil {
			C_obtained = new(C.SDL_AudioSpec)
		} else {
			C_obtained = C_desired
		}
	}

	status := C.SDL_OpenAudio(C_desired, C_obtained)

	if status == 0 {
		mutex.Lock()
		opened++
		mutex.Unlock()
	}

	if obtained_orNil != nil {
		obtained := obtained_orNil

		obtained.Freq = int(C_obtained.freq)
		obtained.Format = uint16(C_obtained.format)
		obtained.Channels = uint8(C_obtained.channels)
		obtained.Samples = uint16(C_obtained.samples)
		obtained.Out_Silence = uint8(C_obtained.silence)
		obtained.Out_Size = uint32(C_obtained.size)
	}

	return int(status)
}

func OpenAudioDevice(device string, iscapture bool, desired, obtained *AudioSpec, allowed_changes bool, callback func(*byte, int)) bool {
	var cdesired C.SDL_AudioSpec
	var cobtained C.SDL_AudioSpec
	cdevice := C.CString(device)
	defer C.free(unsafe.Pointer(cdevice))
	cdesired.freq = C.int(desired.Freq)
	cdesired.format = C.SDL_AudioFormat(int(desired.Format))
	cdesired.channels = C.Uint8(desired.Channels)
	cdesired.samples = C.Uint16(desired.Samples)
	cdesired.size = C.Uint32(0)
	cdesired.callback = C.go_sdl2_get_callback()
	cdesired.userdata = unsafe.Pointer(&callback)
	ret := C.SDL_OpenAudioDevice(cdevice, C.int(bool2int(iscapture)), &cdesired, &cobtained, C.int(bool2int(allowed_changes)))
	if obtained != nil {
		obtained.Freq = int32(cobtained.freq)
		obtained.Format = AudioFormat(int(cobtained.format))
		obtained.Channels = uint8(cobtained.channels)
		obtained.Silence = uint8(cobtained.silence)
		obtained.Samples = uint16(cobtained.samples)
		obtained.Size = uint32(cobtained.size)
	}
	return int(ret) == 0
}