Bug Report Replay Buffer with Rate Control set to CBR records clips shorter than the determined length


New Member
It seems that the Replay Buffer records clips significantly shorter than what I've set when the Rate Control is set to CBR.

For example, Replay Buffer @ 25Mbps set to 300 seconds will end up only recording up to 180 seconds. The file size of the clip is about ~500MB instead of the estimated file size of 907MB shown in the Replay Buffer Tab. x264, NVENC, and NVENC (new) seem to exhibit the same behaviour of not recording the full duration I've set.
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New Member
YES! I have this all the time and I cannot seem to fix it. Really ruins it when I need at least 20 minutes of footage because of long game matches, but instead I get a video that doesn't even last two minutes.

Here is today's log file of OBS:


  • 2019-08-11 17-25-05.txt
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New Member
I came back for another issue which I by now fixed and saw that somebody responded to this thread.
Lucky, because I forgot about this issue completely, whilst I have found a ''workaround'' for myself at least.
So for anyone willing to use the workaround that helped me: I swapped the recording from MP4 to MKV, which I used back when it worked anyways, I think I just forgot about it breaking when I switched to MP4.
So now that I've started using MKV again as video recording type, it works fine and I can now actually record up to the full 20 minutes that I told OBS to record.