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

Cecil Westerhof Cecil at decebal.nl
Wed Dec 15 22:10:39 EET 2021


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.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof


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