Add support alsa source

internal/alsa/alsa.go

@@ -0,0 +1,7 @@
+//go:build !(linux && (386 || amd64 || arm || arm64 || mipsle))
+
+package alsa
+
+func Init() {
+	// not supported
+}

internal/alsa/alsa_linux.go

@@ -0,0 +1,80 @@
+//go:build linux && (386 || amd64 || arm || arm64 || mipsle)
+
+package alsa
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/AlexxIT/go2rtc/internal/api"
+	"github.com/AlexxIT/go2rtc/internal/streams"
+	"github.com/AlexxIT/go2rtc/pkg/alsa"
+	"github.com/AlexxIT/go2rtc/pkg/alsa/device"
+)
+
+func Init() {
+	streams.HandleFunc("alsa", alsa.Open)
+
+	api.HandleFunc("api/alsa", apiAlsa)
+}
+
+func apiAlsa(w http.ResponseWriter, r *http.Request) {
+	files, err := os.ReadDir("/dev/snd/")
+	if err != nil {
+		return
+	}
+
+	var sources []*api.Source
+
+	for _, file := range files {
+		if !strings.HasPrefix(file.Name(), "pcm") {
+			continue
+		}
+
+		path := "/dev/snd/" + file.Name()
+
+		dev, err := device.Open(path)
+		if err != nil {
+			continue
+		}
+
+		info, err := dev.Info()
+		if err == nil {
+			formats := formatsToString(dev.ListFormats())
+			r1, r2 := dev.RangeSampleRates()
+			c1, c2 := dev.RangeChannels()
+			source := &api.Source{
+				Name: info.ID + " / " + info.Name + " / " + info.SubName,
+				Info: fmt.Sprintf("Formats: %s, Rates: %d-%d, Channels: %d-%d", formats, r1, r2, c1, c2),
+				URL:  "alsa:device?audio=" + path,
+			}
+			sources = append(sources, source)
+		}
+
+		_ = dev.Close()
+	}
+
+	api.ResponseSources(w, sources)
+}
+
+func formatsToString(formats []byte) string {
+	var s string
+	for i, format := range formats {
+		if i > 0 {
+			s += " "
+		}
+		switch format {
+		case 2:
+			s += "s16le"
+		case 10:
+			s += "s32le"
+		default:
+			s += strconv.Itoa(int(format))
+		}
+
+	}
+	return s
+}

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: