Wrongly halved framerate, ac3 audio unusable after a channel number switch

[eumagga0x2a]

The most probable reason is 25 fps in the YouTube sample vs. 50 fps in the arte HD one.

Yes, it is: If I reencode the mentioned YouTube sample and insert the "Resample FPS" filter with 50 fps as the target value, I can reproduce the problem.

[Jan Gruuthuse]

Audio Sync Delay Test 30 seconds 720p 50 FPS YouTube Audio Sync Delay Test 30 seconds 50 FPS

50 individual frames, not 25 fps re-encoded to 50 fps

Files (920 KB total), Will be deleted on 11 September, 2016
Mkv Download: 720p50fps30seconds.mkv

[eumagga0x2a]

Thank you for one more perfect sample. Are you able to reproduce the issue with this video and "gtk" Qt theme on your system?

50 individual frames, not 25 fps re-encoded to 50 fps

Actually it doesn't matter much, the tiny sample from YouTube reencoded at 50 fps shows similar AV desync between 10% and 20% on my system. It means, FPS is a very important part of the game here.

[Jan Gruuthuse]

Tested and recorded (25 fps):
- Tested: export QT_STYLE_OVERRIDE=gtk avidemux3_qt5 4K 50 FPS
- Tested: NO export QT_STYLE_OVERRIDE 4K 50 FPS
could not notice different behaviour.

[Jan Gruuthuse]

Hit the hardware ceiling: not able to record the test @ 50 FPS
so bandwidth could be an issue doing video stuff?

[eumagga0x2a]

Confirming that there is no desync with "gtk" Qt theme on your system when playing the 50 fps sample in Avidemux. It doesn't matter that you can't record it at 50 fps, generally it was enough what you see with your own eyes. The only important clue from a screencast was to give a hint about the Qt theme in use. Thank you very much.

Offtopic: Your screencasts show how horribly the current solution for the size of the time display fails on HiDPI screens

[Jan Gruuthuse]

Offtopic: Your screencasts show how horribly the current solution for the size of the time display fails on HiDPI screens

time displays in avidemux GUI? this what you referring to?

[eumagga0x2a]

I mean the small text field showing the current playback position in hh:mm:ss.ms. I submitted a patch to accomodate its contents for the "gtk" Qt theme and usual font sizes (https://github.com/mean00/avidemux2/commit/f520bfce55342e0f2e11b053ee953aa85355a4fb and https://github.com/mean00/avidemux2/commit/80e4934a9dfafbd5c3411bd34d901dcfcad045a8), but it doesn't work nicely with other Qt themes and fails even more on HiDPI according to your screencast. Ideally, the field should be wide enough to allow all digits to fit in with a comfortable padding, but this can't work with fixed sizes specified in pixels.

[Jan Gruuthuse]

perhaps a separate floating window with control and timers? That sizes upto (dynamic) to the current screen it floats on?

[eumagga0x2a]

It looks like recent commits including a partial fix for http://avidemux.org/smif/index.php/topic,17060.0.html have majorly increased the desync effect...

perhaps a separate floating window with control and timers? That sizes upto (dynamic) to the current screen it floats on?

I guess, we shouldn't replace one evil with another