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|
package soundbox
/*
#cgo pkg-config: libpipewire-0.3
#include "pipewire-binding.h"
*/
import "C"
import (
"context"
"fmt"
"io"
"log"
"net"
"os/exec"
"runtime"
"sync"
"unsafe"
)
type pwCapture struct {
cdata unsafe.Pointer
}
var pwAudio chan []byte
// lock makes sure there is always just one PipeWire capture device since
// multiple are not yet implemented.
var lock sync.Mutex
func newPWCapture(ctx context.Context) pwCapture {
pwc := pwCapture{}
pwAudio = make(chan []byte, 5)
pwc.cdata = unsafe.Pointer(C.pw_go_capture_init()) // TODO pass &pwc.audio here
go C.pw_go_capture_run(pwc.cdata)
go func() {
<-ctx.Done()
C.pw_go_capture_deinit(pwc.cdata)
}()
return pwc
}
func (pwc pwCapture) Read(p []byte) (int, error) {
select {
case chunk, ok := <-pwAudio:
if ok {
noSilence := s16leDropSilence(chunk)
i := copy(p, noSilence)
return i, nil
} else {
return 0, io.EOF
}
default:
return 0, nil
}
}
func s16leDropSilence(input []byte) []byte {
output := make([]byte, 0)
cut := len(input) % 4
length := len(input) - cut // s16 raw audio is 4 bytes per sample
for i := 0; i < length; i += 4 {
if input[i+0] == byte(0) &&
input[i+1] == byte(0) &&
input[i+2] == byte(0) &&
input[i+3] == byte(0) {
continue
}
output = append(output, input[i+0])
output = append(output, input[i+1])
output = append(output, input[i+2])
output = append(output, input[i+3])
}
return output
}
func StreamPipewireContext(ctx context.Context, targets []net.HardwareAddr) error {
success := lock.TryLock()
if !success {
return fmt.Errorf("Could not acquire lock")
}
defer lock.Unlock()
if runtime.GOOS != "linux" {
return fmt.Errorf("Only the GNU / Linux operating system is supported")
}
cmd := exec.CommandContext(
ctx,
"ffmpeg",
"-ac",
"2",
"-ar",
"48000",
"-f",
"s16le",
"-channel_layout",
"stereo",
"-i",
"-",
"-acodec",
"flac",
"-f",
"ogg",
"-",
)
stdout, err := cmd.StdoutPipe()
if err != nil {
return err
}
stdin, err := cmd.StdinPipe()
if err != nil {
return err
}
pwc := newPWCapture(ctx)
go func() {
_, err := io.Copy(stdin, pwc)
if err != nil {
log.Println("Failed to copy from PipeWire to ffmpeg.")
}
}()
err = cmd.Start()
if err != nil {
return err
}
err = streamContext(ctx, stdout, targets)
if err != nil {
return err
}
return cmd.Wait()
}
//export goHandleData
func goHandleData(data *C.int16_t, size C.size_t) {
buf := C.GoBytes(unsafe.Pointer(data), C.int(size))
pwAudio <- buf
}
|
