MediaCoder

Hi, I want to use MediaCoder but 1 thing seems to be missing: Constant Ratefactor (CRF) (aka Constant Quality).

I see "Variable Bitrate" as one of the encoding modes, but I do not believe that is the same thing. The default value for Variable Bitrate is 50 whereas the typical default values for Constant Ratefactor are mid 20s.

Does MediaCoder support CRF for H.264? If so, where/how do I use it?

Thanks,
-Neil

Neillithan wrote:Hi, I want to use MediaCoder but 1 thing seems to be missing: Constant Ratefactor (CRF) (aka Constant Quality).

I see "Variable Bitrate" as one of the encoding modes, but I do not believe that is the same thing. The default value for Variable Bitrate is 50 whereas the typical default values for Constant Ratefactor are mid 20s.

Does MediaCoder support CRF for H.264? If so, where/how do I use it?

Thanks,
-Neil

Hi,

actually the "variable bitrate" mode is CRF. If you change the "user interface mode" into the "expert mode" then you can see in the "video options" under in the window of Mediacoder that the CRF will change when e.g. you change the "variable bitrate" from 50 to 60, the CRF will change from 25 to 20.

Thank you. This was an extremely helpful answer.

Expert interface mode should be the only one

actually the "variable bitrate" mode is CRF.

I'm confused as to that. I think that the IU has changed a lot since the last post. I'm in Expert mode right now, but I don't see anything under video options. I use CRF because I prioritize quality over space, and also don't want to bother with calculating bitrate, but under VBR I do?

1-pass encoding is considered by many as CRF (Constant Rate Factor) or Target Quality, in audio encoding its similar to VBR. Is VBR a 1 pass or 2 pass? I heard it was a 2 or 3 pass. How do I control how many passes?
http://doom10.org/index.php?topic=1393.0

I thought that MeGUI was hard.. and I'm torn between that and MediaCoder. MediaCoder is harder with presets, but easier process (don't need to demux video and audio). If there was just a way to import x264 configuration from MeGUI or use its configuration dialouge...

Please help and thank you.

Setting Expert Mode, under Options > User Interface Mode, opens a third panel under the main tabs.
It has tabs of its own: Logger, Audio options, Video options, etc.
The Video Options tab will reveal the commands, etc, during processing.

On the Video tab, above the Expert Mode panel, "Rate Mode" offers Average, Variable and Constant Bitrate, each being 1-pass.
It also offers 2- and 3-pass encoding. There is a brief Guide on these (viewtopic.php?f=17&t=11033).

On selecting Variable Bitrate, the panel above changes to Video Quality, settable from 10 to 99.
The other Rate Mode choices result in this panel offering Video Bitrate instead of Quality.