Add support v4l2 source

internal/v4l2/v4l2.go

@@ -0,0 +1,7 @@
+//go:build !linux
+
+package v4l2
+
+func Init() {
+	// not supported
+}

internal/v4l2/v4l2_linux.go

@@ -0,0 +1,79 @@
+package v4l2
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/AlexxIT/go2rtc/internal/api"
+	"github.com/AlexxIT/go2rtc/internal/streams"
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/AlexxIT/go2rtc/pkg/v4l2"
+	"github.com/AlexxIT/go2rtc/pkg/v4l2/device"
+)
+
+func Init() {
+	streams.HandleFunc("v4l2", func(source string) (core.Producer, error) {
+		return v4l2.Open(source)
+	})
+
+	api.HandleFunc("api/v4l2", apiV4L2)
+}
+
+func apiV4L2(w http.ResponseWriter, r *http.Request) {
+	files, err := os.ReadDir("/dev")
+	if err != nil {
+		return
+	}
+
+	var sources []*api.Source
+
+	for _, file := range files {
+		if !strings.HasPrefix(file.Name(), core.KindVideo) {
+			continue
+		}
+
+		path := "/dev/" + file.Name()
+
+		dev, err := device.Open(path)
+		if err != nil {
+			continue
+		}
+
+		formats, _ := dev.ListFormats()
+		for _, fourCC := range formats {
+			source := &api.Source{}
+
+			for _, format := range device.Formats {
+				if format.FourCC == fourCC {
+					source.Name = format.Name
+					source.URL = "v4l2:device?video=" + path + "&input_format=" + format.FFmpeg + "&video_size="
+					break
+				}
+			}
+
+			if source.Name != "" {
+				sizes, _ := dev.ListSizes(fourCC)
+				for i := 0; i < len(sizes); i += 2 {
+					size := fmt.Sprintf("%dx%d", sizes[i], sizes[i+1])
+					if i > 0 {
+						source.Info += " " + size
+					} else {
+						source.Info = size
+						source.URL += size
+					}
+				}
+			} else {
+				source.Name = string(binary.LittleEndian.AppendUint32(nil, fourCC))
+			}
+
+			sources = append(sources, source)
+		}
+
+		_ = dev.Close()
+	}
+
+	api.ResponseSources(w, sources)
+}