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

pkg/ffmpeg/generate.go

@@ -0,0 +1,42 @@
+package ffmpeg
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+// Generate runs ffmpeg with the given args and waits for it to finish.
+// Returns an error if the command fails. If the command fails, the return
+// value will be of type *exec.ExitError.
+func (f FFMpeg) Generate(ctx context.Context, args Args) error {
+	cmd := f.Command(ctx, args)
+
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("error starting command: %w", err)
+	}
+
+	if err := cmd.Wait(); err != nil {
+		var exitErr *exec.ExitError
+		if errors.As(err, &exitErr) {
+			exitErr.Stderr = stderr.Bytes()
+			err = exitErr
+		}
+		return fmt.Errorf("error running ffmpeg command <%s>: %w", strings.Join(args, " "), err)
+	}
+
+	return nil
+}
+
+// GenerateOutput runs ffmpeg with the given args and returns it standard output.
+func (f FFMpeg) GenerateOutput(ctx context.Context, args []string) ([]byte, error) {
+	cmd := f.Command(ctx, args)
+
+	return cmd.Output()
+}