View Full Version : Multi-threaded encoding using multi-pass


SuNova
20th October 2016, 18:17
Hi. As I know using multiple threads will reduce quality (more or less). So what if I use 8 threads with 5 passes instead of 1 thread and 2 passes? Will increasing number of passes fix this quality loss?

sneaker_ger
20th October 2016, 19:33
No.
But the quality reduction of using 8 threads is negligible anyways. Don't worry about it.

Jamaika
20th October 2016, 21:01
In the test is generally threads one. You get the impression that eight threads is a bad idea, but it isn't true. It is quicker conversion. For CRF is only pass one. Pass two gives the same result.

kral2008
16th November 2016, 09:27
Guys,
Today I tried to convert a video.Mp4 encoded with HEVC MAIN 5.1 ~2500kbps to h264 using handbrake and total codec studio.
The presets are:
X264 Mian 3000kbps and the encode mode is "best" or "insane" in Handbrake.
Mainconcept H264 Mian 3000kbps and the encoding mode was in the slowest.

I configured an HP DL380 G9 server by two intel Xeon 2698 v4 processor and two Samsung 16GB PC4 2400 memory modules and have installed Windows Server 2012.
But what is strange that is that I encountered with very low usage of resources while encoding: only about 7 - 20% usage of CPU :(

Handbrake uses only one CPU, usage is ~ 20%,
But Total code studio uses both of them and all 40 cores, usage is ~ 10%

what's the problem? Why they can't use all power of the processors?

http://i.cubeupload.com/tgbm69.jpg
http://i.cubeupload.com/QMKydK.jpg
http://i.cubeupload.com/YDZtfl.jpg

kuchikirukia
17th November 2016, 01:28
Try disabling hyperthreading and setting threads to 40. You're probably single-thread limited somewhere and it would probably be best if that was pinned to a real core.
Too many lookahead threads? Too few? Try playing around with it.

Motenai Yoda
17th November 2016, 17:28
do you have some bottleneck like ram hdd or use opencl stuff with a low end graphics card?

kral2008
17th November 2016, 18:59
do you have some bottleneck like ram hdd or use opencl stuff with a low end graphics card?


About Ram and HDD, no. But about graphics, yes; cause you can't install any graphics card on severs (unless you use Workstations). The server uses a:
Integrated Matrox G200eH2 video standard with 16MB of Video RAM
• 1280 x 1024 (32 bpp)
• 1920 x 1200 (16 bpp)
and:

HPE iLO 4 On System Management Memory
• 16 MB Flash
• 256 MB DDR3 with ECC (112 MB after ECC and video)
only for a low resolution display to configure the server. Of course you can install Quadro cards like K2000 on servers, but they are very expensive.
I think servers injures from lacking a good enough graphics card.
Could this a problem? Consider that I didn't use any H/W Acceleration in both of Handbrake and Total code studio.

kuchikirukia
18th November 2016, 00:54
If you're not using anything openCL don't worry about it.

Why do you have no drives?

kral2008
18th November 2016, 10:41
If you're not using anything openCL don't worry about it.

Why do you have no drives?

You mean that lack of any usual graphics card has no effect on this process?
Then what is the solution? I see some people have encoded BD media by x265 and its high profiles, the size is about ~70GB, what is the processor and parameters that they use?

Because windows monitoring can't detect the raid system that we made by "p440ar" smart array. however the core of windows and other applications can use it.

Atak_Snajpera
18th November 2016, 17:43
Why don't you encode mutiple chunks simultaneously ?

http://i.cubeupload.com/bFnBKC.png

kral2008
18th November 2016, 19:06
Why don't you encode mutiple chunks simultaneously ?

http://i.cubeupload.com/bFnBKC.png

This could be the best solution.
How can I do that? You mean using vmware on the server, and then creating some virtual machine, then connecting these machines to the main server that has ripbot? or simply, using your application is enough?

Atak_Snajpera
18th November 2016, 21:59
Everything can be done in ripbot.
Setup is very easy
https://www.youtube.com/watch?v=b-BICnj62iE