Question / Help Lossless Recording = Massive Video Bitrate!!?

[BlockAboots]

I am using R1CH guide to produce lossless video captures when using File output mode (so not streaming)....

viewtopic.php?f=18&t=2972

But i have a problem upon setting OBS up with R1CH recommended settings, once i have finished a 20 minute capture the bitrate of the file is something like 95440kbps big, which is massive. This makes it almost impossible to encode the video for editing as it would take almost 9 hrs to encode the file. I usually use Lagarith Lossless codec when capturing with other software and usually video files of the same length come out at around a bitrate 9000-11000kbps!!, so what is OBS doing to cause such large Bitrates?

 

[dodgepong]

Do you think you could post your log from one of those recording sessions? http://obsproject.com/forum/viewtopic.php?f=5&t=97

 

[WayZHC]

If you put crf=0 then ofc it's gonna be massive video bitrate. It's guide how to make HIGH QUALITY local recordings. Not guide how to make Lossless. Lossless doesn't limit the bitrate. crf=0 = Lossless, crf=15-20 = High quality like the guide says. Not recommended setting the recording to lossless. crf=10 - 15 is good enough for very high quality.

 

[BlockAboots]

Do you think you could post your log from one of those recording sessions? http://obsproject.com/forum/viewtopic.php?f=5&t=97

I have attached the log.

If you put crf=0 then ofc it's gonna be massive video bitrate. It's guide how to make HIGH QUALITY local recordings. Not guide how to make Lossless. Lossless doesn't limit the bitrate. crf=0 = Lossless, crf=15-20 = High quality like the guide says. Not recommended setting the recording to lossless. crf=10 - 15 is good enough for very high quality.

Yeah as i said i usually use Lagarith with is a Lossless codec, and the bitrates are no where near the size that OBS is outputting at crf=0

 

[Krazy]

crf=0 is generally not ideal, it tells the encoder "use as much bitrate as you feel like, I don't care" which results in utterly gigantic file sizes like you are experiencing. Comparing crf=0 x264 to Lagarith is pretty pointless

 

[dodgepong]

From R1CH's guide:

Custom x264 parameters: crf=X
Where X is anywhere from 1-20, lower being higher quality / higher CPU usage. A good place to start is the 15 - 20 range. A CRF of 0 enables lossless recording which will have very high file size and CPU requirements, so be careful!

This is why he said to be careful with a crf of 0.

h264 is not really designed to be a lossless video format, as I understand it. You're better off using a crf of 15 or 20 like R1CH suggests.