Bug 455508

Summary: unable to import MKV or MP4 clips containing x.264 video with single stereo audio track. Files downgraded to 'TS' using ffmpeg import OK.
Product: [Applications] kdenlive Reporter: Rick Stockton <rickstockton>
Component: Rendering & ExportAssignee: Jean-Baptiste Mardelle <jb>
Status: RESOLVED UPSTREAM    
Severity: major CC: rickstockton
Priority: NOR    
Version First Reported In: 22.04.2   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Rick Stockton 2022-06-17 19:47:23 UTC 
SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***
Unable to attach a report via the KDE crash handler, it hangs on current OpenSuse Tumbleweed updated today (with Kernel 5.18.2-1-default, melt and most of KDE were updated among 5000+ other packages). New with this version and its co-requisite MELT-7 and FFMPEG4, did not happen yesterday. KDE Apps are version 5.25.0, Frameworks is Tumblweed 5.94.0.

STEPS TO REPRODUCE
1. Create a project.
2. Add a valid and playable MP4 or MKV clip, containing one track of Stereo audio using codec AAC (LAV), OPUS, or AC3.
OBSERVED RESULT
 Instant crash results, with failing KDE crash handler.

EXPECTED RESULT
Successful Import to the Project.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: OpenSuse Tumbleweed, rev 06/06/14/2022 mlweed 
(available in About System)
KDE Plasma Version:  5.25.0
KDE Frameworks Version: 5.90.4
Qt Version: 5.15.2+kde294-5.4

ADDITIONAL INFORMATION

Converted the Camera's "native" AC3 audio to Opus. AAC. and a re-encoded AC3 within both an MKV and MP4 container (with -moveflags present in the MP4 container conversion). No alternative audio version was succesfully imported. I did not (yet) try importing the video track alone. Failing file size was about 20GB.

BYPASS:
A failing large file can be exported to a single long "ts" output file using an external tool such as avidemux; the 'ts' version can then be imported to kdenlive without issues.
Comment 1 Rick Stockton 2022-06-21 13:33:14 UTC 
With this comment, I reference a 'failing' MP4 clip (kdenlive crash upon import), along with a 'working bypass' MTS file. Both play within VLC, and import to other manipulation apps (handbrake, avidimux, etc). Although these files contain an irrelevant audio recode to OPUS, the import problem is related to the video, not the audio.

When the MTS is imported to this project, KDE correctly offers to modify the FPS of the project to match the clip, and when I choose not to do that, the clip is adapted to the project's specified profile. Either choice is successful. But, when the MP4 is imported, kdenlive crashes. (Sometimes with a Dr Konqi popup, sometimes without.)

The MTS was created from the MP4 using this simple ffmpeg command:
     ffmpeg -i out2.mp4 -c:v copy -c:a copy out2.mts

- - -

This may be a critical hint: For the failing MP4 file input file, ffmpeg shows "59.94 fps, 59.94 tbr, 30k tbn, 119.88 tbc (default)"

For the 'succeeding' MTS output file from ffmpeg, ffmpeg shows specification changes to tbn and tbc: "59.94 fps, 59.94 tbr, 90k tbn, 30k tbc (default)"

- - -
MP4 file download: https://drive.google.com/file/d/17JMkKClcMJZJbnfY5428nf3lS24h8ffL/view?usp=sharing
MTS file download: https://drive.google.com/file/d/1-W0uBkgvN3Od8YzGCA49E_JKvyswHqWN/view?usp=sharing
Empty Project Download: https://drive.google.com/file/d/1_LHyzty2F0sciM520r_ao5SAUSkb6Jes/view?usp=sharing
Comment 2 Rick Stockton 2022-06-26 18:29:15 UTC 
following an upgrade to today's released tumbleweed version, the MP4 file imports OK. A new and upgraded version of Melt was included, replacing Melt 7.6  (which had the problem).

Kdelinve "Version 22.04.2". 
Melt Version "7.8.0", Tumbleweed RPM version "7.8.0-1.1"

Marking RESOLVED - UPSTREAM by changes in MELT 7.8.0