Question new Options tune and lookahead -level

[bitspyer]

Hi,

can you explain what the benefits of the options tune and lookahead-level are?

I made some tests and i got now diffrences in size and bitrate, when i encode a UHD Sample to hevc.

Greetz, Bitspyer

[rigaya]

--lookahead-level All I know is what is described in the NVENC SDK, it says as below.

< [in]: Specifies the lookahead level. Higher level may improve quality at the expense of performance.

[quamt]

Hi,

can you explain what the benefits of the options tune and lookahead-level are?

I made some tests and i got now diffrences in size and bitrate, when i encode a UHD Sample to hevc.

Greetz, Bitspyer

What are your encoding parameters? How did you verify the difference in "quality"? Certain settings in video encoding can improve the perceived quality of a video without significantly changing the file size.

[bitspyer]

For testing I first used very few options:

--y4m --preset quality --qvbr 20 --max-bitrate 50000

second run with extra option --lookahead 32 --lookahead-level 3 --tune uhq

checked both runs with vmaf and the diffrence was little and i think because the second run with the new options made the file with higher bitrate.

Another Test was with a "fixed" bitrate : made 2 runs with --vbr 5000 and now there was a small advantage for lookahead-level and tune at smaller filesize

Maybe the new options may be usefull for low bitrates and not if you use qvbr with high bitrates