Add support alsa source

internal/ffmpeg/ffmpeg.go

@@ -113,6 +113,7 @@ var defaults = map[string]string{
 	"pcm/48000":  "-c:a pcm_s16be -ar:a 48000 -ac:a 1",
 	"pcml":       "-c:a pcm_s16le -ar:a 8000 -ac:a 1",
 	"pcml/8000":  "-c:a pcm_s16le -ar:a 8000 -ac:a 1",
+	"pcml/16000": "-c:a pcm_s16le -ar:a 16000 -ac:a 1",
 	"pcml/44100": "-c:a pcm_s16le -ar:a 44100 -ac:a 1",
 
 	// hardware Intel and AMD on Linux

internal/ffmpeg/producer.go

@@ -42,6 +42,7 @@ func NewProducer(url string) (core.Producer, error) {
 			Codecs: []*core.Codec{
 				// OPUS will always marked as OPUS/48000/2
 				{Name: core.CodecOpus, ClockRate: 48000, Channels: 2},
+				{Name: core.CodecPCML, ClockRate: 16000},
 				{Name: core.CodecPCM, ClockRate: 16000},
 				{Name: core.CodecPCMA, ClockRate: 16000},
 				{Name: core.CodecPCMU, ClockRate: 16000},
@@ -97,6 +98,8 @@ func (p *Producer) newURL() string {
 			s += "#audio=opus"
 		case core.CodecAAC:
 			s += "#audio=aac/16000"
+		case core.CodecPCML:
+			s += "#audio=pcml/16000"
 		case core.CodecPCM:
 			s += "#audio=pcm/" + strconv.Itoa(int(codec.ClockRate))
 		case core.CodecPCMA: