[x264-devel] Strange problem with encoder.. maybe

[Steve Green]

Hi all..

I’m new to x.264 and struggling to solve a problem.  The context here is ffmpeg, avcodec, x.264, etc.. streaming live to the internet.  Honestly I don’t know if the issue has something to do with x.264 or one of the other layers but it seems like it’s encoder related so I’m starting here.

If I encode/stream motion video, everything is fine.  I can also stream a static image without issue.  Switching back and forth between the two is also very smooth.  The problem arises when I leave the still image in the stream for a long period of time.  After about 30 minutes, when I switch back to motion video, the CPU spikes out of control, the data rate goes through the roof and I start dropping.  This eventually settles down but it takes several minutes.

I’ve noticed that if I change the gop_size from 90, to 15, this problem is minimized.  Im told, however, that 90 is greatly preferred and it seems to me that I should be able to make this work with 90.

Can anyone offer some suggestions?

Thanks!