x264 AMD-AMF CRF -- resulting bitrate is too high

  • Did simple comparison x264 CPU vs x264 AMD-AMF with similar options.

    From defaults I only changed to CRF=21

    Voukoder x264 CPU rendered test project with bitrate about 20 Mbps. I rendered the project with x264 encoder (through MeGUI) many times and bitrate was about the same.

    However, when I rendered the project using Voukoder x264 AMD-AMF encoder with the same options, the resulting bitrate was about 50+ Mbps that looks a bit too high.

    So I think it might be a few things:

    1. x264 AMF is really produces much worse quality and so for the same CRF encoder uses higher bitrate to meet quality requirements;

    2. Voukoder does not pass or incorrectly pass some settings to x264 AMF and so the high bitrate is used.

    Could you advice, how can I check what is causing the "issue"?


  • fifonik

    Changed the title of the thread from “AMD-AMF CRF -- resulting bitrate is too high” to “x264 AMD-AMF CRF -- resulting bitrate is too high”.
  • First, x264 is an encoder for the h264 codec. Just like there is an AMD h264 encoder, but not an AMD x264 encoder.

    I would suggest you to test this with FFmpeg. Voukoder is always using the latest versions of all components from GIT master.

  • I tried to render the same file in Handbrake with x264 CRF23 vs H264 AMD VCE (Quality) CRF23.

    The second file is 4+ times bigger and there are no B-frames in it at all (I was just told that VCE does not make the B-frames while encoding. Did not know that).

    So this is not the Voukoder issue, just ignore the "bug report"


  • Vouk

    Added the Label Not a bug
  • Vouk

    Set the Label from Magix Vegas to Independent
  • Hi! I want to confirm this kind of bug. I use premiere 2019 on win7, Ryzen 1800x, Radeon RX550, 32 gb

    I try to use HEVC AMD AMF encoder in voukoder 2.2 and 2.3
    The essence of the problem is that the encoder does not respond to the settings. At strategy CQP at any parameter of quantizer the bitrate of the final file turns to 150 MBs. At strategy CBR at setting of a bitrate in limits from 0 to 100Mbs the total will be about 100 MBs, at setting of higher bitrate it will be equal to the srttings. So, when choosing CBR, I can not encode with a bitrate less than 100 MBs!

    [Blocked Image: https://ibb.co/18WJy3k]