[FFmpeg-user] itsoffset breaking overlay filter

[Tim Willison]

Hi guys,
I have actually filed a bug for this one (#2467) but I'm wondering if
anyone else is experiencing a problem with using -itsoffset on the input
pad for the overlay filter. I've used this technique many times to delay
the start of an overlay, but the latest ffmpeg seems to have a problem.
Every time I apply -itsoffset to an overlay, I get "Buffer queue overflow,
dropping" repeated.

This happens even when I'm just generating the video right inside ffmpeg:
ffmpeg -f lavfi -i color=c=0xFFFFFF:s=1280x720:r=30:sar=1 -itsoffset -2 -f
lavfi -i color=c=0x000000:s=1280x720:r=30:sar=1 -filter_complex 'overlay'
-vframes 240 -y mytest.mp4

I have tried encoding to a wide variety of formats and the output is always
the same.

[Parsed_overlay_0 @ 0x34788c0] Buffer queue overflow, dropping.

Is anybody else experiencing this? Unfortunately I can't think of many ways
to offset an overlay without the -itsoffset flag, other than resorting to
chopping the video up, overlaying, then joining it again. (Overlays that
have no -itsoffset come out just fine).

-Timbot