80 lines
1.7 KiB
Go
80 lines
1.7 KiB
Go
|
//go:build overlord_webrtc
|
||
|
|
|
||
|
|
package webrtcpub
|
||
|
|
|
||
|
|
import (
|
||
|
|
"sync"
|
||
|
|
"time"
|
||
|
|
|
||
|
|
"github.com/pion/webrtc/v4"
|
||
|
|
"github.com/pion/webrtc/v4/pkg/media"
|
||
|
|
"github.com/thesyncim/gopus"
|
||
|
|
)
|
||
|
|
|
||
|
|
const (
|
||
|
|
opusInputRate = 48000
|
||
|
|
opusChannels = 2
|
||
|
|
opusPacketMs = 20
|
||
|
|
opusSamplesPerFrame = opusInputRate * opusPacketMs / 1000
|
||
|
|
opusBitrate = 96000
|
||
|
|
)
|
||
|
|
|
||
|
|
type opusAudioWriter struct {
|
||
|
|
t *webrtc.TrackLocalStaticSample
|
||
|
|
encoder *gopus.Encoder
|
||
|
|
mu sync.Mutex
|
||
|
|
pcm []int16
|
||
|
|
packet []byte
|
||
|
|
}
|
||
|
|
|
||
|
|
func newOpusAudioWriter(t *webrtc.TrackLocalStaticSample) (*opusAudioWriter, error) {
|
||
|
|
encoder, err := gopus.NewEncoder(gopus.EncoderConfig{
|
||
|
|
SampleRate: opusInputRate,
|
||
|
|
Channels: opusChannels,
|
||
|
|
Application: gopus.ApplicationAudio,
|
||
|
|
})
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
if err := encoder.SetBitrate(opusBitrate); err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
if err := encoder.SetInBandFEC(gopus.InBandFECEnabled); err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
return &opusAudioWriter{
|
||
|
|
t: t,
|
||
|
|
encoder: encoder,
|
||
|
|
pcm: make([]int16, 0, opusSamplesPerFrame*4),
|
||
|
|
packet: make([]byte, 4000),
|
||
|
|
}, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func (w *opusAudioWriter) WriteAudio(pcm []int16) error {
|
||
|
|
if len(pcm) == 0 {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
w.mu.Lock()
|
||
|
|
defer w.mu.Unlock()
|
||
|
|
w.pcm = append(w.pcm, pcm...)
|
||
|
|
frameValues := opusSamplesPerFrame * opusChannels
|
||
|
|
for len(w.pcm) >= frameValues {
|
||
|
|
n, err := w.encoder.EncodeInt16(w.pcm[:frameValues], w.packet)
|
||
|
|
if err != nil {
|
||
|
|
w.pcm = w.pcm[:0]
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
if n > 0 {
|
||
|
|
if err := w.t.WriteSample(media.Sample{
|
||
|
|
Data: w.packet[:n],
|
||
|
|
Duration: opusPacketMs * time.Millisecond,
|
||
|
|
}); err != nil {
|
||
|
|
w.pcm = w.pcm[:0]
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
w.pcm = w.pcm[frameValues:]
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|