FFmpeg output is stuck if using split with fps filter

[TheTroll]

Summary of the bug:
How to reproduce:

% ffmpeg -re -y -i INPUT -filter_complex "[0:v]split=2[o0][sthumb];[sthumb]fps=1/60[othumb]" -an -c:v libx264 -map [o0] out.ts -map [othumb] -update 1 out.png

Built on master

When trying to transcode an input live stream while extracting thumbnails (every minute in this example), using the split and fps filters, FFmpeg gets blocked and eventually generates the output after a while, by bursts.

The following warning indicates that something is wrong:

[out_#0:0 @ 0x7f1018013c00] 100 buffers queued in out_#0:0, something may be wrong.

FFmpeg 5.1.2 works fine and as expected.

Thanks

[Gyan]

Why the -re for a live stream?

[TheTroll]

Hi,

Because to make a quick test, you can use any source file and use -re to make it act as a live stream.
You can obtain the same issue removing -re and using a live URl as input.

thanks

[Gyan]

What about

ffmpeg -y -i LIVE_INPUT -an -c:v libx264 -map 0:v out.ts -map 0:v -filter:v "fps=1/60" -update 1 out.png

[TheTroll]

OMG that helped! Thanks for the trick.
That's a good one, I wonder why the split thing doesnt work anymore though?

[Marton Balint]

Fixed in 42bcbdd456d1ca2aa2d0665840830f0a5bf8be39.