[digiKam-users] Building digikam sources with ffmpeg 5

[Gilles Caulier]

Hi Steven,

You're welcome to help us to complete the ffmpeg 5 port of digiKam
media player code.

You are right QtAV has been integrated in digiKam core as it's not
maintained since february 2022.

The QtAV core+widgets is located here :

https://invent.kde.org/graphics/digikam/-/tree/master/core/libs/video/qtav

Please read all the tasks already completed in this code and listed in
the README file.

The code compiles with Qt5/Qt6 and ffmpeg4/5. To test and hack ffmpeg
5 port, Qt5 is enough. I recommend to use Linux as host operating
system..

The ffmpeg detection and all compilation configuration for the
mediaplayer is located in this cmake script :

https://invent.kde.org/graphics/digikam/-/blob/master/core/cmake/rules/RulesMediaPlayer.cmake

I think there is nothing to tune here, as the ffmpeg5 port to complete
is located in qtav. the compilation still have warnings to fix. Also
there are lock when video start to be played. It's probably due to the
ffmpeg init order not yet fully compliant in source code, and
especially with classes located here :

https://invent.kde.org/graphics/digikam/-/tree/master/core/libs/video/qtav/ffmpeg

To hack, look well the debug traces on the console. To enable debug
trace, please follow the instructions here :

https://www.digikam.org/contribute/

Also, digiKam include now the QtAV unit test, and examples :

https://invent.kde.org/graphics/digikam/-/tree/master/core/tests/video/qtav

and of course the stand alone video player :

https://invent.kde.org/graphics/digikam/-/tree/master/core/avplayer

With this last one, you must be able to test video playback without to
use the whole digiKam application.

Voilà for a first start

Best

Gilles Caulier

Le mar. 5 juil. 2022 à 04:08, Steven Robbins <steve at sumost.ca> a écrit :
>
> Hello Gilles,
>
> On Sunday, July 3, 2022 10:43:22 P.M. CDT Gilles Caulier wrote:
>
> > ...It's a bad idea to compile digiKam with ffmpeg 5. digiKam code is
> > not yet finalized (even if it compiles) and playing video will not
> > work. Use the ffmpeg 4.x LTS instead.
>
> That would be sensible; however, Debian has just transitioned to ffmpeg 5,
> removing ffmpeg 4 so this option is no longer available to me.
>
> After reading through bugs #453840 and #448681, I got the impression that
> there is a fair bit of effort going into porting -- after incorporating qtav
> into the digikam codebase.  I thought I'd jump in to see if I can be of help.
> Clearly, I don't know the code base at present, so that will be a first goal.
>
> Regards,
> -Steve