Best codecs for 6800XT

[Dogoslov]

Hi, I am observing a high CPU demand and wonder, what is the correct codec to use? Here are my current settings that only get me to 55% GPU utilization (I have a Ryzen 5800X CPU for reference if that info is needed).

[k4yt3x]

The default encoder is libx264 which uses CPU for encoding. You can either try changing the preset to something faster or use a hardware encoder like h264_amf, h264_vulkan, or h264_vaapi. You can also try the HEVC encoders, just replace h264 with hevc.

Btw I recommend you to not change the bit_rate and rc_buffer_size and use CRF instead.

[Dogoslov]

Thank you so much, I will try that out!

[Dogoslov]

I tried every option and variation (Vulkan refused to work at all, same for vaapi, tells me the pixel format isn't supported, tried all formats I could find), nothing made a difference in performance or loading of my CPU and GPU. :(

I also found that using the bit_rate and rc_buffer_size is the only way to ensure constant bitrate and a consistent quality for my applications as I want as little compression as possible, I both upscale and interpolate the same material and dislike compression overall.

[k4yt3x]

If you have FFmpeg installed, you can do something like this to check which pixel formats are supported for a given encoder:

Also make sure you're using 6.4.0. The older versions have a bug that cause the wrong encoder to be used. Also, when you do processing with, say, h264_amf, do you see an increase in GPU encoder usage?

[Dogoslov]

I am not familiar enough with FFmpeg, how exactly do I run it to do what you ask me to do? I have no experience with things that seem to require commands and more advanced methods beyond running a .exe file.

[k4yt3x]

Ok here's a summary:

• Don't worry about FFmpeg if you don't want to deal with commands.
• Use yuv420p as the pixel format if you want to use the hardware accelerated h264_amf encoder. Otherwise if you have to use yuv444p, use a software encoder like libx264.
• You can set CRF to a lower value like 17 for better quality. If it still doesn't work for you, sure you can set bit_rate.
• You can export it into a lossless format like lossless H.264 or ffv1 between two runs to minimize the compression artifact over multiple processing runs. TL;DR: set codec to ffv1 for the first run.

[k4yt3x]

Feel free to keep asking if you still have questions.