Video's bitrate greatly exceeds the one set in the settings

[JustAGuy123]

Hi!

A friend of mine recorded a 720p 60fps video which is 1:12 long and it takes up a whopping 335 MB. It has a bitrate of 39012 kbps even though she set it to 2500 in the settings. Does anyone have a clue why that's happening? I use basically the same settings but my videos never exceed the limit. Thanks!

 

[JustAGuy123]

Here is the log file:

 

[R1CH]

13:49:56.292: [AMF] [H264]<Id: 3> Rate Control:
13:49:56.292: [AMF] [H264]<Id: 3> Method: Constant Quantization Parameter

It looks like you were using CQP mode, so bitrate is irrelevant.

 

[JustAGuy123]

13:49:56.292: [AMF] [H264]<Id: 3> Rate Control:
13:49:56.292: [AMF] [H264]<Id: 3> Method: Constant Quantization Parameter

It looks like you were using CQP mode, so bitrate is irrelevant.

The thing is, she used the program with the default settings. The only difference from mine was that the program is using an AMD hardware encoder which seems to ignore the settings. I told her to switch to a different encoder and see if it works. When she does, I'll update on that.

 

[JustAGuy123]

13:49:56.292: [AMF] [H264]<Id: 3> Rate Control:
13:49:56.292: [AMF] [H264]<Id: 3> Method: Constant Quantization Parameter

It looks like you were using CQP mode, so bitrate is irrelevant.

Yeah, switching to the x264 software encoder helped.

Here's the log:

 

[qhobbes]

The AMD hardware encoder is not ignoring those settings, they just do not apply. CRF is a “constant quality” encoding mode. If it's going to take 10000 kb to encode 1 second of video at the desired quality, then the encoder will do that. AFAIK x264 has a better quality to size ratio than AMD so the file *should* be smaller at the desired quality.

 

[JustAGuy123]

The AMD hardware encoder is not ignoring those settings, they just do not apply. CRF is a “constant quality” encoding mode. If it's going to take 10000 kb to encode 1 second of video at the desired quality, then the encoder will do that. AFAIK x264 has a better quality to size ratio than AMD so the file *should* be smaller at the desired quality.

My friend was using default settings and CBR is used by default (I just deleted my %appdata%/obs-studio folder to doublecheck that) so the program wasn't supposed to ignore the bitrate setting but it did because of the AMD's encoder which was selected by default, too.