weee

internal/coverart/coverart.go

@@ -77,7 +77,11 @@ func (s *Store) ExtractEmbedded(ctx context.Context, mediaPath string, streamInd
 		"-map", fmt.Sprintf("0:%d", streamIndex),
 		"-frames:v", "1",
 		"-c:v", "copy",
-		"--", tmp.Name(),
+		// Temporary files deliberately have a neutral .img suffix. Tell
+		// ffmpeg which muxer to use instead of asking it to infer one from
+		// that suffix. ffmpeg does not accept `--` as an end-of-options
+		// marker, so including it here made every embedded-art request fail.
+		"-f", "image2", tmp.Name(),
 	)
 	if out, err := cmd.CombinedOutput(); err != nil {
 		os.Remove(tmp.Name())

internal/coverart/coverart_test.go

@@ -1,6 +1,7 @@
 package coverart
 
 import (
+	"context"
 	"image"
 	"image/color"
 	"image/jpeg"
@@ -9,6 +10,33 @@ import (
 	"testing"
 )
 
+func TestExtractEmbeddedSuppliesExplicitOutputFormat(t *testing.T) {
+	dir := t.TempDir()
+	argsPath := filepath.Join(dir, "args")
+	fakeFFmpeg := filepath.Join(dir, "ffmpeg")
+	script := "#!/bin/sh\nprintf '%s\\n' \"$@\" > \"$ARGS_PATH\"\n"
+	if err := os.WriteFile(fakeFFmpeg, []byte(script), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv("ARGS_PATH", argsPath)
+
+	store := New(dir, fakeFFmpeg)
+	path, err := store.ExtractEmbedded(context.Background(), filepath.Join(dir, "song.mp3"), 2)
+	if err != nil {
+		t.Fatalf("ExtractEmbedded: %v", err)
+	}
+	defer os.Remove(path)
+
+	args, err := os.ReadFile(argsPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := string(args)
+	if got != "-y\n-v\nerror\n-i\n"+filepath.Join(dir, "song.mp3")+"\n-map\n0:2\n-frames:v\n1\n-c:v\ncopy\n-f\nimage2\n"+path+"\n" {
+		t.Fatalf("unexpected ffmpeg arguments:\n%s", got)
+	}
+}
+
 func writeTestJPEG(t *testing.T, path string, w, h int) {
 	t.Helper()
 	img := image.NewRGBA(image.Rect(0, 0, w, h))