Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Video Encoding > High Efficiency Video Coding (HEVC)

 
 
Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
Old 22nd April 2020, 17:08   #1  |  Link
excellentswordfight
Lost my old account :(
 
Join Date: Jul 2017
Posts: 174
CRF use for content aware VOD streaming?

Hi,

So there are a lot of discussions regarding content aware/per-title streaming for VOD nowdays, were different types of methods are used to select what bitrate is appropriate when it comes to streaming.

old, but yeah basically this:
https://netflixtechblog.com/per-titl...n-7e99442b62a2

But it seems like a lot of streaming services (i guess at least most of the smaller local ones) still just use fixed bitrates for the ladder, cause I guess they dont have resources to implement complex workflows.

So I've been wondering, why isnt CRF used (or is it?)? Cant it be in used together with vbv restrictions to create a crude method to do this?

I'm a bit out of my realm of expertise here but. Lets say you have a 1Mbps connection target preset, why not set a crf value that is close to 500Kbps in avg bitrate for your average complexity material, then set --vbv-maxrate 750 --vbv-bufsize 1000. I'm I missing something or shouldn't this be a fairly good (or at least easy) way of doing it compared to fixed bitrates?

So a ladder would look something like this:

540p24 ~500Kbps (1Mbps safe) --crf 26 --vbv-maxrate 750 --vbv-bufsize 1000

720p24 ~1250Kbps (2Mbps safe) --crf 24 --vbv-maxrate 1750 --vbv-bufsize 2500

1080p24 ~3Mbps (5Mbps safe) --crf 22 --vbv-maxrate 4500 --vbv-bufsize 6000

1080p24 ~6Mbps (10Mbps safe) --crf 19 --vbv-maxrate 9000 --vbv-bufsize 12000

So, my question is basically: is this a good or a poor way of doing it? If good, is this already in widespread use, and if not, why?

Last edited by excellentswordfight; 22nd April 2020 at 17:28.
excellentswordfight is offline   Reply With Quote
 

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 12:11.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.