[FFmpeg-user] creating a grid like Zoom

Moritz Barsnick barsnick at gmx.net
Wed May 20 12:40:19 EEST 2020

Hi Michael,

On Tue, May 19, 2020 at 10:25:17 -0700, Michael Glenn Williams wrote:
> We tried following the examples of making grids when reading live streams
> liek this:
> https://www.reddit.com/r/ffmpeg/comments/aimdx9/ffserver_video_grid_source_ffserver_http_ts/
> With the example:

Using that example works fine for you, right? It does for me. (I would
probably simplify the example using the "scale2ref", "hstack" and
"vstack" filters, but that's not the point.)

> We wrote the output into a file output.mkv for testing. However when we
> playback the file it has a terrible flickering, see this output sample:
> https://www.dropbox.com/s/58gj99u0ezplscw/output.mkv?dl=0

Oh, indeed.

> Any thoughts on what we are doing wrong?

Yes, but first:

> The actual bash code is something like this:

Though I can read bash, could you kindly provide us the actual
resulting command line (perhaps extracted using "bash -x"), and
ffmpeg's complete, uncut console output?

I do have a suspicion: Your framerates (or image timings), and perhaps
your resolutions, don't align very well. We may see from the output
log. Perhaps we can recommend some additional options or filters to


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