Bug 489156

Summary:	Kdenlive audio effects do not work with "Unexpected return format"
Product:	[Applications] kdenlive	Reporter:	ericswpark <kde-bugtracking>
Component:	Audio Effects & Transitions	Assignee:	Jean-Baptiste Mardelle <jb>
Status:	CONFIRMED ---
Severity:	normal
Priority:	NOR
Version First Reported In:	24.05.1
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description ericswpark 2024-06-25 03:53:35 UTC

SUMMARY
Attempting to use an audio effect, such as Dialoguenhance, causes an "Unexpected return format" error with the effect not working.

I've tested the folllowing effects and they do not work, showing an error message:

- Dialoguenhance
- Speechnorm

STEPS TO REPRODUCE
1. Use the effect on a video clip with audio
2. Start playback

OBSERVED RESULT
A small error window pops up in the "Effect/Composition Stack" panel, saying "[filter avfilter.dialoguenhance] Unexpected return format". The title of the error window says "Dialoguenhance". (See attached screenshot.)

The effect also does not have any effect on the clip.

EXPECTED RESULT
The effect works on the clip.

SOFTWARE/OS VERSIONS
Windows: 11, Version 23H2 (OS Build 22631.3737)

ADDITIONAL INFORMATION
I've attached a demo project with the associated clip.

Comment 1 ericswpark 2024-06-25 03:56:02 UTC

Because of filesize limitations I've uploaded the associated clip to this temporary file storage site: https://litter.catbox.moe/fcqhjs.MP4
The link expires after 24 hours.

Comment 2 ericswpark 2024-06-25 04:41:10 UTC

*** Bug 489155 has been marked as a duplicate of this bug. ***

Comment 3 Jean-Baptiste Mardelle 2024-06-26 08:40:52 UTC

Currently, Kdenlive displays all FFmpeg (avfilters) available filters. However, some of them are not compatible with MLT frameworks (our AV backend). We are in the process of creating a list of curated effects that we know are working and hide the others to prevent such issues.

From the docs, Dialoguenhance produces surround (3.0) channels output from a stereo input. Changing the channel layout in an effect is not currently not supported.

I am not sure about Speechnorm, but can confirm it also doesn't work.

As I said, we are going to improve this by hiding non working effects, hopefully in the 24.08 release