problems with ogv video

[kursh]

Thanks for your time. I have readed that post of 2023. It seems a problem of ags or the way we created de ogv file. ( i used vlc)

Im watching here..

[Rik_Vargard]

If I may, I'd like to insist on the "pitch black screen" again. And I mean when the screen is 100% black (#000000) . 

I made a quick 20 secs video that I exported in MP4 and converted in OGV.
And as always, it looks perfect in VLC.

Please notice the long black screen moment around the 9th second.

>> https://www.mediafire.com/file/e0d62n14m96ka3y/_AGStest03.ogv/file

Then, I recorded how that video plays in AGS.
And there you will see that the black screen moment is "ignored" and that at the end the video stops at the last frame, waiting for the music to finish.

>> https://www.mediafire.com/file/61o8mwm6vdbgy73/AGStest03inEDITOR.mp4/file

And that's why we have the illusion that the movie goes faster than the sound, when in fact those black frames are skipped.
Maybe they're considered "empty" or something?

[Crimson Wizard]

@Rik_Vargard could you please make a video that contains only black frames, and then a single non-black frame in the end?
(or a single frame at start, then black frames, and single frame at end)
With such video it will be much easier to investigate what the video decoder is doing.

[kursh]

The thing is that my video has only few black frames (less than a second) at the start.. but sound goes about 2 o 3 seconds later. i hope you can detect whats really happening!

[Rik_Vargard]

@Rik_Vargard could you please make a video that contains only black frames, and then a single non-black frame in the end?
(or a single frame at start, then black frames, and single frame at end)
With such video it will be much easier to investigate what the video decoder is doing.

I made a 2 seconds video with one colored frame at the beginning and one colored frame at the end.

>> https://www.mediafire.com/file/1wsrvrs6tyep3ce/AGStest04.mp4/file

I hope this is what you asked?

[Crimson Wizard]

>> https://www.mediafire.com/file/1wsrvrs6tyep3ce/AGStest04.mp4/file

Please tell, how do you normally convert this to ogv? I'd like to use exact same method and settings, to be certain that i'm testing same situation.

[kursh]

While we wait for Rik answer... i used VLC convert with Theora video codec and vorbis sound codec.

[Rik_Vargard]

Ah yes, I sent you the MP4 file... here's the converted OGV >> https://www.mediafire.com/file/iav9sldg5g7q0ja/AGStest04.ogv/file

I use this website to convert the videos >> https://video.online-convert.com/convert-to-ogv
The only setting I fill in is the first; the bitrate, I set it at 20000 kbps

And this is the info about their compression >> https://www.theora.org/

[Crimson Wizard]

I was only able to confirm the problem, and found an old mail-list entry about a very similar error in Theora decoding:
https://ffmpeg.org/pipermail/libav-user/2011-June/000212.html

From my understanding, it goes down into libogg (OGG reading library). It's not likely that anything in the engine code itself is causing this, but libogg skips certain data packets for some reason.
... OR our code that uses libogg does not react and handle specific result.

But I never used libogg library myself, so cannot tell yet.

I still have a backup variant of comparing with VLC code, but I will need more time to figure out how to read it and what to compare...

[Rik_Vargard]

I was only able to confirm the problem, and found an old mail-list entry about a very similar error in Theora decoding:
https://ffmpeg.org/pipermail/libav-user/2011-June/000212.html

From my understanding, it goes down into libogg (OGG reading library). It's not likely that anything in the engine code itself is causing this, but libogg skips certain data packets for some reason.
... OR our code that uses libogg does not react and handle specific result.

But I never used libogg library myself, so cannot tell yet.

I still have a backup variant of comparing with VLC code, but I will need more time to figure out how to read it and what to compare...

Thank you for that report and for taking the time to look into this 

I guess that for now, we'll just have to avoid black frames 

[kursh]

thanks you both for your time. Maybe its time to try some near "black" RGB(10,10,10) frames.. maybe it works.. maybe no....