High CPU usage when built against ffmpeg 5.x

[xvitaly]

Steps to reproduce

1. Build Telegram Desktop against packaged ffmpeg 5.x (5.0 or 5.1, doesn't matter).
2. Run built app.
3. Join supergroup/channel with a lot of video stickers/avatars.
4. Check CPU usage in top/htop.

Expected behaviour

Standard CPU usage.

Actual behaviour

100% CPU usage on all CPU cores. The official binary is not affected yet, but it will after upgrading from ffmpeg 4.4 to 5.x.

Downstream bug report with some logs: https://bugzilla.rpmfusion.org/show_bug.cgi?id=6273

Operating system

Fedora 36

Version of Telegram Desktop

4.0.2

Installation source

Other (unofficial) source

Logs

No response

[ilya-fedin]

ffmpeg 5 is not supported yet. Please switch to ffmpeg 4 or fix ffmpeg 5 on your own.

[xvitaly]

@Aokromes Why did you close this issue? The official package will be affected too after upgrading from ffmpeg 4.4 to 5.x. It should be opened for tracking purposes.

[ilya-fedin]

It will be upgraded to ffmpeg 5 only after precise testing and fixing any obvious bugs. Until then, this is an unsupported configuration.

[xvitaly]

Please switch to ffmpeg 4

Impossible. Most distributions already moved to 5.1. 4.x branch will reach EOL very soon.

[ilya-fedin]

Well, if you need it, implement it.

[xvitaly]

@ilya-fedin Please stop being so rude.

[ilya-fedin]

You can't requisite something on GitHub and then saying someone is rude just because one doesn't want to implement something you want. People implement what they want. You want ffmpeg 5? Go ahead, implement it. You can't force anyone else to do the work you're interested in.

[xvitaly]

@ilya-fedin Flatpak runtime 22.08 will have ffmpeg 5. Two weeks left.

[ilya-fedin]

It won't be used until preston would like to migrate to ffmpeg 5. Or until someone else implement the support.

[john-preston]

@xvitaly BTW did you report it to ffmpeg bug tracker?

Looks like an ffmpeg regression when the same code works fine with ffmpeg 4.4 and works bad with ffmpeg 5.x 🙄

[GeorgesStavracas]

@ilya-fedin first please allow me to apologize for the confusion above. The fact that the FreeDesktop runtime 22.08 will ship with FFmpeg 5 is only a minor inconvenience, since Telegram can bundle the precise FFmpeg version it needs to (OBS Studio needs to ship a patched version of FFmpeg, so there's precedent for it.)

I see that you're actively committing to this repository, and maintaining the Flathub build, so you're probably in position to determine which version of FFmpeg the Flathub build will ship. So for the sake of clarity, do you think you or anyone could document this strict FFmpeg 4 dependency somewhere? REAME.md perhaps? So that least other packagers will know what to expect from this app's dependencies.

[ilya-fedin]

Looks like an ffmpeg regression when the same code works fine with ffmpeg 4.4 and works bad with ffmpeg 5.x

There was a big API break, maybe the code is not valid anymore?

So for the sake of clarity, do you think you or anyone could document this strict FFmpeg 4 dependency somewhere?

There's no place where supported versions are documented, the only way is to look at the Dockerfile the official binary is created from

[ilya-fedin]

since Telegram can bundle the precise FFmpeg version it needs to (OBS Studio needs to ship a patched version of FFmpeg, so there's precedent for it.)

I don't like to build ffmpeg manually due to all that configuration argument hell. I would rather prefer to stick with 21.08 until tdesktop starts working with ffmpeg 5.

[GeorgesStavracas]

Sticking to 21.08 is absolutely fine too

[ilya-fedin]

@GeorgesStavracas do you know what openssl version will be in 22.08, btw? openssl 3 is also a blocker, group calls don't work with it.

[GeorgesStavracas]

According to their GitLab project, that'll be openssl 3.0.5

[xvitaly]

do you know what openssl version will be in 22.08, btw?

From changelog:

Update openssl to openssl-3.0.5.

since Telegram can bundle the precise FFmpeg version it needs

Don't forget to resolve licensing issues, like paying patent royalties to MPEG LA for H.264, H.265 and AAC.

[GeorgesStavracas]

Sure

[ilya-fedin]

Telegram is residing in a country where codec patents don't exist

[xvitaly]

Telegram is residing in a country where codec patents don't exist

But US/AU users can still download and use it.

Looks like an ffmpeg regression when the same code works fine with ffmpeg 4.4 and works bad with ffmpeg 5.x roll_eyes

There are a lot of ffmpeg deprecation warnings due compilation.

[ilya-fedin]

No one would pay royalties. I also don't think flathub pays any royalties.

[xvitaly]

I also don't think flathub pays any royalties.

It depends on where they are legally registered. Also they don't provide ffmpeg-full by default. org.freedesktop.Platform.ffmpeg-full is a separate extension.

[ilya-fedin]

It's still provided 🤷‍♂️

[xvitaly]

It's still provided

This is a very interesting question. I will ask Flathub admins.