Dropping it to 22 produces about the same file sizes as x264 18 RF, and the encode performance improves. With NvEnc, I first left it at 18 and got the large file sizes. I turn off all filters (including deinterlace).
I don't use the default Handbrake presets.
These are DVD rips, 682 x 360 anamorphic, not high def. My tests with H.265 are even more dramatic in favor of NvEnc. I'm seeing a 30x performance difference (yes, 30 times faster) with NvEnc H.264 vs software x264, so my results definitely don't agree. HandBrake 1.2.2 (2019022300) Operating system and version (e.g., Ubuntu 18.04 LTS, macOS 10.14 Mojave, Windows 10 1809)Įncavcodec: encoding at rc=constqp QP Interesting. Or at least provide the option to change it, or allow the extra options to override that rc setting which we can't right now. With NVEnc, the equivalent to CRF is 'rc=vbr' with 'cq', 'qmin' and 'qmax' set, which produces an actual Constant Quality / CRF in one pass, but with a variable bit rate, and thus without the downside of wasting disk space like 'rc=constqp'.Ĭan you please change the implementation to use the equivalent of CRF instead of QP ? However, the other part of the problem is that 'constqp' unnecessarily wastes disk space and should be avoided! If interested, see also this additional explanation about why to avoid Constant QP => under the section "Constant QP (CQP)". So the wording in the UI is misleading by saying 'Constant Quality' (but at least it does display QP after it - but only advanced users would understand the subtle difference!). NVEnc has an actual 'Constant Quality' mode equivalent to CRF (by setting 'rc=vbr' and 'cq' instead of 'qp' - note also, it seems to necessary to set 'qmin' and 'qmax' to the same 'cq' value otherwise the quality setting isn't properly adhered to - at least, that is the case when using ffmpeg.) However, Constant QP 'constqp' is not the same as Constant Quality / CRF.
When NVEnc is selected as the video codec, the UI quality setting says "Constant Quality: xx QP", which sets 'rc=constqp' - a setting for the "Quantization Parameter".
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