Adds support local USB cameras

cmd/ffmpeg/device_darwin.go

@@ -0,0 +1,63 @@
+package ffmpeg
+
+import (
+	"bytes"
+	"github.com/AlexxIT/go2rtc/pkg/streamer"
+	"os/exec"
+	"strings"
+)
+
+// https://trac.ffmpeg.org/wiki/Capture/Webcam
+const deviceInputPrefix = "-f avfoundation"
+
+func deviceInputSuffix(videoIdx, audioIdx int) string {
+	video := findMedia(streamer.KindVideo, videoIdx)
+	audio := findMedia(streamer.KindAudio, audioIdx)
+	switch {
+	case video != nil && audio != nil:
+		return `"` + video.Title + `:` + audio.Title + `"`
+	case video != nil:
+		return `"` + video.Title + `"`
+	case audio != nil:
+		return `"` + audio.Title + `"`
+	}
+	return ""
+}
+
+func loadMedias() {
+	cmd := exec.Command(
+		tpl["bin"], "-hide_banner", "-list_devices", "true", "-f", "avfoundation", "-i", "dummy",
+	)
+
+	var buf bytes.Buffer
+	cmd.Stderr = &buf
+	_ = cmd.Run()
+
+	var kind string
+
+	lines := strings.Split(buf.String(), "\n")
+process:
+	for _, line := range lines {
+		switch {
+		case strings.HasSuffix(line, "video devices:"):
+			kind = streamer.KindVideo
+			continue
+		case strings.HasSuffix(line, "audio devices:"):
+			kind = streamer.KindAudio
+			continue
+		case strings.HasPrefix(line, "dummy"):
+			break process
+		}
+
+		// [AVFoundation indev @ 0x7fad54604380] [0] FaceTime HD Camera
+		name := line[42:]
+		media := loadMedia(kind, name)
+		medias = append(medias, media)
+	}
+}
+
+func loadMedia(kind, name string) *streamer.Media {
+	return &streamer.Media{
+		Kind: kind, Title: name,
+	}
+}