[FFmpeg-devel] [PATCH] libavfilter/vf_overlay_cuda: Pass the main frame to the output if secondary frame is not available. now filter fails if secondary frame is not available due to e.g secondary source delay.

[Alex Pokotilo]

On Fri, Aug 21, 2020 at 7:54 PM Nicolas George <george at nsup.org> wrote:
>
> Alex Pokotilo (12020-08-21):
> > From b3739e33fa04a9292dc6584bd2f31460aa53d478 Mon Sep 17 00:00:00 2001
> > From: Alex Pokotilo <support at wmspanel.com>
> > Date: Fri, 21 Aug 2020 09:14:37 +0000
> > Subject: [PATCH] libavfilter/vf_overlay_cuda: Pass the main frame to the output if secondary frame is not
> >  available. now filter fails if secondary frame is not available due to e.g secondary source delay.
>
> Your Git commit message is badly formatted. The format is:
>
>         context: short summary on one line
>
>         After an empty line, details if necessary, on several lines and
>         wrapped at a reasonable line length.
>

I'm sorry. I'm a newbie. Am I right I just need to commit in following format:

first line: short description......
LF
more details here

Should I send a new patch as a separate email or reply to this one ?
Sorry again.
> The fix may be correct, but your analysis of the problem does not prove
> it. Unless there is a serious bug in framesync, it will not call
> overlay_cuda_blend() without a secondary frame "due to e.g secondary
> source delay.", it will only do so if the stream has not yet begun or
> has ended.
>
> Please give more details on the exact circumstances you observe the
> issue.

I create a filter graph with vf_cuda_overlay in my application. I
start sending frames into a "main" stream link using
av_buffersrc_write_frame.
I start sending frames into a "secondary" stream too almost
immediately. I have one output sink in my filter graph.
After each write I call av_buffersink_get_frame and get AVERROR_BUG
from vf_overlay_cuda for some time initially but after several frames
it starts returning mixed frame.
I've checked vf_blend and other framesync filters. They do the same as
I did in the fix.

Maybe the problem In my application I cannot guarantee that both
streams have the same timeline.
Could you please point me to the place where framesync checks second
stream availability before it calls it's filter(overlay_cuda_blend in
my case).
This topic is very complex to me now so any help from your side can
really help me.