fix: Handle None lyrics in pipeline input

ambsd · ambsd · commit 33d385c05d0b · 2026-01-29T12:39:49.000+02:00
heartlib's preprocess() expects lyrics to be a string, not None.
Pass empty string when lyrics is not provided.
diff --git a/backend/app/services/music_service.py b/backend/app/services/music_service.py
@@ -1529,7 +1529,7 @@ def _run_pipeline():
 
                     with torch.no_grad():
                         pipeline_inputs = {
-                            "lyrics": request.lyrics,
+                            "lyrics": request.lyrics or "",  # heartlib expects string, not None
                             "tags": sound_tags,
                         }
                         if ref_audio_path:

Original file line number	Diff line number	Diff line change
`@@ -1529,7 +1529,7 @@ def _run_pipeline():`
`1529`	`1529`
`1530`	`1530`	`with torch.no_grad():`
`1531`	`1531`	`pipeline_inputs = {`
`1532`		`- "lyrics": request.lyrics,`
	`1532`	`+ "lyrics": request.lyrics or "", # heartlib expects string, not None`
`1533`	`1533`	`"tags": sound_tags,`
`1534`	`1534`	`}`
`1535`	`1535`	`if ref_audio_path:`