Rewrite FFmpeg devices and add support ALSA for Linux

internal/ffmpeg/device/device_darwin.go

@@ -3,24 +3,41 @@ package device
 import (
 	"github.com/AlexxIT/go2rtc/internal/api"
 	"github.com/AlexxIT/go2rtc/pkg/core"
+	"net/url"
 	"os/exec"
 	"regexp"
 	"strings"
 )
 
-// https://trac.ffmpeg.org/wiki/Capture/Webcam
-const deviceInputPrefix = "-f avfoundation"
+func queryToInput(query url.Values) string {
+	video := query.Get("video")
+	audio := query.Get("audio")
 
-func deviceInputSuffix(video, audio string) string {
-	switch {
-	case video != "" && audio != "":
-		return `"` + video + `:` + audio + `"`
-	case video != "":
-		return `"` + video + `"`
-	case audio != "":
-		return `":` + audio + `"`
+	if video == "" && audio == "" {
+		return ""
 	}
-	return ""
+
+	// https://ffmpeg.org/ffmpeg-devices.html#avfoundation
+	input := "-f avfoundation"
+
+	if video != "" {
+		video = indexToItem(videos, video)
+
+		for key, value := range query {
+			switch key {
+			case "resolution":
+				input += " -video_size " + value[0]
+			case "pixel_format", "framerate", "video_size", "capture_cursor", "capture_mouse_clicks", "capture_raw_data":
+				input += " -" + key + " " + value[0]
+			}
+		}
+	}
+
+	if audio != "" {
+		audio = indexToItem(audios, audio)
+	}
+
+	return input + ` -i "` + video + `:` + audio + `"`
 }
 
 func initDevices() {

internal/ffmpeg/device/device_linux.go

@@ -3,19 +3,36 @@ package device
 import (
 	"github.com/AlexxIT/go2rtc/internal/api"
 	"github.com/AlexxIT/go2rtc/pkg/core"
+	"net/url"
 	"os"
 	"os/exec"
 	"regexp"
 	"strings"
 )
 
-// https://trac.ffmpeg.org/wiki/Capture/Webcam
-const deviceInputPrefix = "-f v4l2"
+func queryToInput(query url.Values) string {
+	if video := query.Get("video"); video != "" {
+		// https://ffmpeg.org/ffmpeg-devices.html#video4linux2_002c-v4l2
+		input := "-f v4l2"
 
-func deviceInputSuffix(video, audio string) string {
-	if video != "" {
-		return video
+		for key, value := range query {
+			switch key {
+			case "resolution":
+				input += " -video_size " + value[0]
+			case "video_size", "pixel_format", "input_format", "framerate", "use_libv4l2":
+				input += " -" + key + " " + value[0]
+			}
+		}
+
+		return input + " -i " + indexToItem(videos, video)
 	}
+
+	if audio := query.Get("audio"); audio != "" {
+		input := "-f alsa"
+
+		return input + " -i " + indexToItem(audios, audio)
+	}
+
 	return ""
 }
 
@@ -57,4 +74,15 @@ func initDevices() {
 			streams = append(streams, stream)
 		}
 	}
+
+	err = exec.Command(Bin, "-f", "alsa", "-i", "default", "-t", "1", "-f", "null", "-").Run()
+	if err == nil {
+		stream := api.Stream{
+			Name: "ALSA default",
+			URL:  "ffmpeg:device?audio=default#audio=opus",
+		}
+
+		audios = append(audios, "default")
+		streams = append(streams, stream)
+	}
 }

internal/ffmpeg/device/device_windows.go

@@ -3,12 +3,58 @@ package device
 import (
 	"github.com/AlexxIT/go2rtc/internal/api"
 	"github.com/AlexxIT/go2rtc/pkg/core"
+	"net/url"
 	"os/exec"
 	"regexp"
 )
 
-// https://trac.ffmpeg.org/wiki/DirectShow
-const deviceInputPrefix = "-f dshow"
+func queryToInput(query url.Values) string {
+	video := query.Get("video")
+	audio := query.Get("audio")
+
+	if video == "" && audio == "" {
+		return ""
+	}
+
+	// https://ffmpeg.org/ffmpeg-devices.html#dshow
+	input := "-f dshow"
+
+	if video != "" {
+		video = indexToItem(videos, video)
+
+		for key, value := range query {
+			switch key {
+			case "resolution":
+				input += " -video_size " + value[0]
+			case "video_size", "framerate", "pixel_format":
+				input += " -" + key + " " + value[0]
+			}
+		}
+	}
+
+	if audio != "" {
+		audio = indexToItem(audios, audio)
+
+		for key, value := range query {
+			switch key {
+			case "sample_rate", "sample_size", "channels", "audio_buffer_size":
+				input += " -" + key + " " + value[0]
+			}
+		}
+	}
+
+	if video != "" {
+		input += ` -i video="` + video + `"`
+
+		if audio != "" {
+			input += `:audio="` + audio + `"`
+		}
+	} else {
+		input += ` -i audio="` + audio + `"`
+	}
+
+	return input
+}
 
 func deviceInputSuffix(video, audio string) string {
 	switch {

internal/ffmpeg/device/devices.go

@@ -1,6 +1,7 @@
 package device
 
 import (
+	"errors"
 	"github.com/AlexxIT/go2rtc/internal/api"
 	"net/http"
 	"net/url"
@@ -16,45 +17,23 @@ func Init(bin string) {
 }
 
 func GetInput(src string) (string, error) {
+	i := strings.IndexByte(src, '?')
+	if i < 0 {
+		return "", errors.New("empty query: " + src)
+	}
+
+	query, err := url.ParseQuery(src[i+1:])
+	if err != nil {
+		return "", err
+	}
+
 	runonce.Do(initDevices)
 
-	input := deviceInputPrefix
-
-	var video, audio string
-
-	if i := strings.IndexByte(src, '?'); i > 0 {
-		query, err := url.ParseQuery(src[i+1:])
-		if err != nil {
-			return "", err
-		}
-		for key, value := range query {
-			switch key {
-			case "video":
-				video = value[0]
-			case "audio":
-				audio = value[0]
-			case "resolution":
-				input += " -video_size " + value[0]
-			default: // "input_format", "framerate", "video_size"
-				input += " -" + key + " " + value[0]
-			}
-		}
+	if input := queryToInput(query); input != "" {
+		return input, nil
 	}
 
-	if video != "" {
-		if i, err := strconv.Atoi(video); err == nil && i < len(videos) {
-			video = videos[i]
-		}
-	}
-	if audio != "" {
-		if i, err := strconv.Atoi(audio); err == nil && i < len(audios) {
-			audio = audios[i]
-		}
-	}
-
-	input += " -i " + deviceInputSuffix(video, audio)
-
-	return input, nil
+	return "", errors.New("wrong query: " + src)
 }
 
 var Bin string
@@ -68,3 +47,10 @@ func apiDevices(w http.ResponseWriter, r *http.Request) {
 
 	api.ResponseStreams(w, streams)
 }
+
+func indexToItem(items []string, index string) string {
+	if i, err := strconv.Atoi(index); err == nil && i < len(items) {
+		return items[i]
+	}
+	return index
+}