[FFmpeg-user] h.265 crf values corresponding with h.264

[Ferdi Scholten]

Cecil Westerhof via ffmpeg-user <ffmpeg-user at ffmpeg.org> writes:
>> Ferdi Scholten <ferdi at sttc-nlp.nl> writes:
>>
>>> On 15-12-2021 18:18, Cecil Westerhof via ffmpeg-user wrote:
>>>> When looking at:
>>>>       https://trac.ffmpeg.org/wiki/Encode/H.265
>>>>
>>>> with h.265 the value 28 should correspond with the value 23 with
>>>> h.264.
>>>> Is there a (rough) table for the other values?
>>>>
>>> Well, no not really
>>>
>>> Those figures are generic. In reality there are many things that can
>>> affect both quality and size.
>>> The kind of video used as a source, the amount of visual detail, the
>>> preset used or other settings all have a big impact either on size or
>>> quality of the encode.
>>>
>>> So what is your goal, would you want high quality, small file sizes or
>>> fast encoding speed? All these things you need to trade off to get to
>>> your optimum encoding settings. Do some trial runs with small samples to
>>> find out what suits your needs.
>> In a way all three. ;-)
>>
>> But my first impression it is not worth it. (After a very short test.)
>> It seems that h.265 generates a marginal smaller file, with a marginal
>> better quality, but takes two times as much computer power.
> In another case h.265 took 2/3 longer, but the size was 3/5. So that
> could be interesting.
>
I have used H265 for a while. Generally it is quite good, but there are 
cases that H264 is better. Anyway, encoding time usually is longer on 
H265, By the way, found a possible answer for your original question:
https://write.corbpie.com/ffmpeg-h265-preset-crf-comparison-2020-pt1/