install go2rtc on bob

installs_on_host/go2rtc/internal/ffmpeg/version.go

@@ -0,0 +1,46 @@
+package ffmpeg
+
+import (
+	"errors"
+	"os/exec"
+	"sync"
+
+	"github.com/AlexxIT/go2rtc/pkg/ffmpeg"
+)
+
+var verMu sync.Mutex
+var verErr error
+var verFF string
+var verAV string
+
+func Version() (string, error) {
+	verMu.Lock()
+	defer verMu.Unlock()
+
+	if verFF != "" {
+		return verFF, verErr
+	}
+
+	cmd := exec.Command(defaults["bin"], "-version")
+	b, err := cmd.Output()
+	if err != nil {
+		verFF = "-"
+		verErr = err
+		return verFF, verErr
+	}
+
+	verFF, verAV = ffmpeg.ParseVersion(b)
+
+	if verFF == "" {
+		verFF = "?"
+	}
+
+	// better to compare libavformat, because nightly/master builds
+	if verAV != "" && verAV < ffmpeg.Version50 {
+		verErr = errors.New("ffmpeg: unsupported version: " + verFF)
+	}
+
+	log.Debug().Str("version", verFF).Str("libavformat", verAV).Msgf("[ffmpeg] bin")
+
+	return verFF, verErr
+}