93 lines
1.7 KiB
Go
93 lines
1.7 KiB
Go
package main
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// typedef unsigned char Uint8;
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// void AudioCallback(void *userdata, Uint8 *stream, int len);
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import "C"
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import (
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"io/ioutil"
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"log"
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"net/http"
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"reflect"
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"unsafe"
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"github.com/veandco/go-sdl2/sdl"
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)
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const (
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sampleHz = 48000
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)
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var (
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audioData []byte
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)
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//export AudioCallback
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func AudioCallback(userdata unsafe.Pointer, stream *C.Uint8, length C.int) {
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n := int(length)
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hdr := reflect.SliceHeader{Data: uintptr(unsafe.Pointer(stream)), Len: n, Cap: n}
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buf := *(*[]C.Uint8)(unsafe.Pointer(&hdr))
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if len(audioData) == 0 {
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for i := 0; i < n; i++ {
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buf[i] = 0
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}
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} else {
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for i := 0; i < n; i++ {
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if i >= len(audioData) {
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break
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}
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buf[i] = C.Uint8(audioData[i])
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}
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if n <= len(audioData) {
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// Remove processed audio data
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audioData = audioData[n:]
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} else {
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// Clear audio data
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audioData = audioData[len(audioData):]
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}
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}
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}
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// Handle audio data that is sent through HTTP
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// Must be stereo unsigned 8-bit audio data at 48000Hz to play correctly
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func audioHandler(w http.ResponseWriter, r *http.Request) {
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data, err := ioutil.ReadAll(r.Body)
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if err != nil {
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w.WriteHeader(http.StatusInternalServerError)
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return
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}
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audioData = append(audioData, data...)
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w.WriteHeader(http.StatusOK)
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}
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func main() {
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if err := sdl.Init(sdl.INIT_AUDIO); err != nil {
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log.Println(err)
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return
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}
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defer sdl.Quit()
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spec := &sdl.AudioSpec{
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Freq: sampleHz,
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Format: sdl.AUDIO_U8,
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Channels: 2,
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Samples: sampleHz,
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Callback: sdl.AudioCallback(C.AudioCallback),
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}
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if err := sdl.OpenAudio(spec, nil); err != nil {
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log.Println(err)
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return
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}
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defer sdl.CloseAudio()
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sdl.PauseAudio(false)
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http.HandleFunc("/audio", audioHandler)
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log.Fatal(http.ListenAndServe(":8080", nil))
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}
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