Restructure ffmpeg (#2392)

* Refactor transcode generation
* Move phash generation into separate package
* Refactor image thumbnail generation
* Move JSONTime to separate package
* Ffmpeg refactoring
* Refactor live transcoding
* Refactor scene marker preview generation
* Refactor preview generation
* Refactor screenshot generation
* Refactor sprite generation
* Change ffmpeg.IsStreamable to return error
* Move frame rate calculation into ffmpeg
* Refactor file locking
* Refactor title set during scan
* Add missing lockmanager instance
* Return error instead of logging in MatchContainer

internal/manager/log.go

@@ -0,0 +1,15 @@
+package manager
+
+import (
+	"errors"
+	"os/exec"
+
+	"github.com/stashapp/stash/pkg/logger"
+)
+
+func logErrorOutput(err error) {
+	var exitErr *exec.ExitError
+	if errors.As(err, &exitErr) {
+		logger.Errorf("command stderr: %v", string(exitErr.Stderr))
+	}
+}