"Static" Video causes buffer underflows

[jdachik01]

A video containing static (replicating loss of video signal) causes ffmpeg to throw buffer underflow errors when transcoding to MPEG-2 (1080i).

ffmpeg -i BVV.mpg -s 1920x1080 -top 1 -aspect 16:9 -threads 16 -vcodec mpeg2video -vb 10600k -minrate 10600k -maxrate 10600k -bufsize 4M -r 29.97 -pix_fmt yuv420p -bf 2 -g 15 -y -acodec ac3 -dialnorm -24 -ar 48000 -ab 192k -f mpegts BV_i.mpg

ffmpeg version N-54233-g86190af

[jdachik01]

Input/source file

[jdachik01]

Log file showing errors

[Michael Niedermayer]

Your bitrate is too low for this video. If you want to encode at this bitrate you can enable trellis and increase lmax but quality will suffer.
Ive improved the printed warning to suggest these

[jdachik01]

Would you be able to provide the exact syntax that would allow encoding at these low bit rates?

This is constant bit rate encoding, but quality for this video is not crucial.

[jdachik01]

You can disregard, I was able to find settings that work.

Thank you!

[jdachik01]

I was able to make usable video with these settings:
-trellis 1
-lmax 420*QP2LAMBDA

Hope this helps anyone affected by this issue. Thank you for pointing out the options I should invoke.

And FYI - even though the -lmax setting seems to be geared toward VBR, these options worked with my CBR output.