Bug 384499

Summary: audio glitches after trimming certain audio streams (FLAC, MP3)
Product: [Applications] kdenlive Reporter: S. Christian Collins <s_chriscollins>
Component: Rendering & ExportAssignee: Jean-Baptiste Mardelle <jb>
Status: RESOLVED FIXED    
Severity: normal CC: fritzibaby
Priority: NOR Flags: fritzibaby: Brainstorm+
Version First Reported In: 17.08.0   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: audio files for repro
video showing the bug

Description S. Christian Collins 2017-09-08 16:49:05 UTC 
Created attachment 107758 [details]
audio files for repro

When edits are being made to an audio or video file, there will often be an audible stutter just after the cut point. This seems to affect some formats/codecs more than others, and these stutters end up in the rendered video.

Steps to reproduce:
1. Create a new Kdenlive project, and save it.
2. Edit the saved .kdenlive file by replacing each instance of the word "combine" with "sum" to remove bug 371849 from the equation.
3. Re-open the Kdenlive project.
4. From the attached audio file archive, add "sine-440-30s.flac" to an audio track.
5. Double-click the clip and set the crop start to: 00:00:21:11.
6. Play the project

Result: There is a stutter at the beginning of the clip that should not be there. This stutter gets rendered when exporting video. This bug does not seem to affect .wav or .ogg files. MP3 files will glitch after the first playthrough, but the glitch is not rendered to the exported video.

Possibly related:
1. Set the crop start of the .flac file to 00:00:29:05. The first playthrough of the clip will stutter, but subsequent playthroughs have no audio until the very end. This missing audio glitch is not rendered to the exported video.

Please see the attached video for a demonstration of this bug.
Comment 1 S. Christian Collins 2017-09-08 16:50:18 UTC 
Created attachment 107759 [details]
video showing the bug
Comment 2 S. Christian Collins 2017-09-08 16:52:47 UTC 
Almost forgot... here's info on my setup:

Kdenlive: 17.08.1
MLT: compiled from git (reported as 6.5.0 by Kdenlive)
OS: KDE Neon 5.10.5 64-bit (Plasma Desktop 5.10.5, KDE Frameworks 5.37.0, Qt 5.9.1)
Linux Kernel: 4.10.0.33-generic
CPU: Intel Core i7 930 (2.8 GHz quad-core)
RAM: 12GB DDR3
Video: NVIDIA GeForce GTX 970 w/ 4GB RAM (PCI Express)
NVIDIA video driver: 375.66
Comment 3 emohr 2018-12-28 14:39:19 UTC 
Thank you for reporting.

Please try with the current Kdenlive_Nightly_Appimage
https://binary-factory.kde.org/job/Kdenlive_Nightly_Appimage_Build/lastSuccessfulBuild/artifact/

Run the Appimage from the terminal (press CTRL + ALT + T). Move to the AppImage folder and run the .AppImage: ./Kdenlive*.AppImage

I run the AppImage on a Virtual Machine under Windows 7 and get weird results.
Comment 4 S. Christian Collins 2018-12-30 15:54:33 UTC 
I can no longer reproduce any element of this bug using the latest nightly (kdenlive-19.03.70-b7d4afd-x86_64.appimage) on KDE neon 18.04 with Plasma 5.14.4.

Closing the bug as "fixed".