Video sound disjointed on Kiwix-Desktop (Linux & Windows)

kiwix / kiwix-desktop

Kiwix for Windows and GNU/Linux desktops

https://download.kiwix.org/release/kiwix-desktop/

GNU General Public License v3.0

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Video sound disjointed on Kiwix-Desktop (Linux & Windows) #425

Closed Popolechien closed 4 years ago

Popolechien commented 4 years ago

Steps to reproduce:

Kiwix desktop 2.0.1 on Windows10
Download https://download.kiwix.org/zim/other/thaki_ar_tech_tricks_2020-04.zim
Play any video - it's in arabic so just for comparison purposes let's go with Translating webpages which is on Youtube.
When playing this video, the speaker can be heard at 0:05 saying "merhaba" then starting a sentence, be interrupted, and restart the very same sentence around 0:12
The issue appears with any video from the list. For instance with Writing in Arabic - starts at 0:05, sound restarts at 0:07.

Videos also stop a few seconds before the end.

Tested the same zim file on Android and had no issue whatsoever.

kelson42 commented 4 years ago

@Popolechien Do you have reproduced this problem an an other Windows computer?

Popolechien commented 4 years ago

@kelson42 yes

kelson42 commented 4 years ago

@Popolechien Thank you very much for this bug report. I can confirm the problem with Kiwix-Desktop 2.0.1 on Linux (Flathub version). The same file served via kiwix-serve with firefox works perfectly. So this is a probably a problem with the reader part.

@mgautierfr Any idea what happens here?

kelson42 commented 4 years ago

@rgaudin It seems somehow related to the video. Video about Mali does not have this pb. But video about skin done in March has a glitch as the beginning as well. I suspect we have here a correlation beetween (a bug?) in the content and in the reader.

rgaudin commented 4 years ago

One thing we could do is run this without --low-quality to check whether our compression has an impact on it.

rgaudin commented 4 years ago

FYI the only change we added was to set the target sample rate to 44Khz.

kelson42 commented 4 years ago

https://download.kiwix.org/zim/other/mali-pour-les-nuls_fr_all_2019-12.zim seems not impacted
https://download.kiwix.org/zim/other/mali-pour-les-nuls_fr_all_2020-04.zim seems impacted

I suspect something has changed in the way the videos are encoded in the meantime.

I move the ticket to openzim/youtube as I believe there is more chances to fix the problem there.

rgaudin commented 4 years ago

Shouldn't we open a different ticket for youtube? That's probably a quick fix there but it looks like this is an upstream (Qt) bug that we should track.

Youtube is somewhat flexible in what it receives and sends and we're also creating ZIMs with videos from outside youtube. Fixing videos might not always be an option.

rgaudin commented 4 years ago

Closing in favor of #433 which compiles the various video playing issues.