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)

Reply
 
Thread Tools Search this Thread Display Modes
Old 1st November 2017, 02:51   #1  |  Link
dooley2009
Registered User
 
Join Date: May 2017
Posts: 6
Confusion over using decoders and encoders

I have been on a quest to accomplish one thing.... and I can't figure it out.

I want to find the best decoder to use when I am using FFmpeg and x265-10bit.

I convert x264 8 bit videos into H.265 HEVC 10 bit. I am trying to speed the process up as much as is possible and maximize the quality as that is more important to me than space. I'm sure someone will tell me that i am wishing for the stars here but I didn't know what to do at this point and really need help.

I have been running into a lot of encoding errors for example using this CLI

Code:
ffmpeg -y -hwaccel cuvid -c:v h265_cuvid -i <INPUT.mp4> -c:v libx265 -cq 21 -preset medium -profile:v main10 -x265-params sao=0:deblock=0:interlace=0:input-res=1920x1080:range=full:colorspace=rgb -c:a aac <OUTPUT.mp4>
I keep picking decoders and encoders that do not get along and i get all kinds of error codes. I really don't understand where I can go to research this exact topic. It is safe to say that I am under the impression that if I find a good decoder to use that it will speed up my efforts. Please correct me if I'm wrong.

Can anyone give me some direction and any opinions that you have on what is the current (today) top encoder and decoders?

Thank you in advance.

Last edited by dooley2009; 1st November 2017 at 02:53. Reason: missed a few inputs in the CLI line
dooley2009 is offline   Reply With Quote
Old 1st November 2017, 18:47   #2  |  Link
benwaggoner
Moderator
 
Join Date: Jan 2006
Location: Portland, OR
Posts: 2,984
If you have 8-bit source, it'll be safer and faster to just encode in 8-bit. Setting output to full range RGB 10-bit is doing a whole lot of interpolation from an 8-bit limited range 4:2:0 source. That's going from 12 bits per pixel to 30 bits per pixel, and ffmpeg's >8-bit filters just aren't that good or well documented. Also, that file is going to be a lot more challenging to decode. Just pass through the 8-bit limited range 4:2:0 as is. That should easily double your encoding speed while you're at it.

Turning off SAO and deblock from previously encoded sources likely will just increase bitrate; the detail those would nominally preserve likely isn't there in the first place.

I'd just go with -preset slower (which is where all the good stuff from HEVC gets turned on) without other parameters and see what you get.
__________________
Ben Waggoner
Principal Video Specialist, Amazon Prime Video

My Compression Book
benwaggoner is offline   Reply With Quote
Old 2nd November 2017, 03:43   #3  |  Link
dooley2009
Registered User
 
Join Date: May 2017
Posts: 6
Great Points

Quote:
Originally Posted by benwaggoner View Post
If you have 8-bit source, it'll be safer and faster to just encode in 8-bit. Setting output to full range RGB 10-bit is doing a whole lot of interpolation from an 8-bit limited range 4:2:0 source. That's going from 12 bits per pixel to 30 bits per pixel, and ffmpeg's >8-bit filters just aren't that good or well documented. Also, that file is going to be a lot more challenging to decode. Just pass through the 8-bit limited range 4:2:0 as is. That should easily double your encoding speed while you're at it.

Turning off SAO and deblock from previously encoded sources likely will just increase bitrate; the detail those would nominally preserve likely isn't there in the first place.

I'd just go with -preset slower (which is where all the good stuff from HEVC gets turned on) without other parameters and see what you get.

I am definitely going to give your idea's a spin. I have been thinking about the practicality of taking an 8 bit video with limited color range and catapulting it to full blown color and my only thought is that the technology is either available to do it efficiently and with good results or it is not (at least for the vast majority of us. ie $$$). I was just reading today that mixing presets with a lot of individual settings can cause real trouble as the preset itself can clash with them.

Anyways thank you very much and I hope some others will chime in on their experiences and personal preferences.

Cheers.
dooley2009 is offline   Reply With Quote
Reply

Tags
cli, decoders, encoders, ffmpeg, x265

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 01:18.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.