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Codecs experiments 1

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#1 Alex Ramos

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Posted 14 February 2017 - 04:33 PM

Hello all,

Check how the different codecs affect performance on a certain machine.

Im using 4 DisplayPort outputs at 1920x1080.
CPU i5 3450
HDD 1TB system
SSD 60GB Corsair Force 3
GPU FirePro V7900
Windows 7 Pro
Wachout 6.1.5

All the videos use the same media except for the codec on of the background movie.
Used codecs for background are:
MPEG 2 GOP15 @33Mbs
MPEG 2 iFrame only @50Mbs
H264 AVC @7.972kbs
HAP @374Mbs

The 6 flags showing on top of the background are Animation+. Each flag is a file.

Check the resources as I load more media.
MPEG 2 runs good for the most, stuttering from time to time.
H264 crashed Wachout as RAM use goes above 4GB
HAP run great.

Please give me your opinion and reviews.
Why is the MPEG 2 stuttering ? SSD use is low 60Mbs max, CPU and GPU also very low.
Why is H264 crashing Wachout ?
MPEG 2 GOP15 @33Mbs 
MPEG 2 iFrame only @50Mbs 
H264 AVC @7.972kbs
HAP @374Mbs

Comments please

#2 Thomas Leong

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Posted 15 February 2017 - 02:58 AM

Hi Alex,


I had a glance at your video examples, and have one question: that you/we are viewing them on a Production PC. However, your Stage Window shows a curved desk as well as the wall of monitors.


1. Is that a live video capture of the studio scene? If yes, this means a more resources are being used at the same time on the Production PC (live video capture).


2. In my own tests, I have noticed that the Production PC's performance as seen in the Stage Window may be lower than the Display PC. Together with Windows Explorer, WatchMaker uses more resources than Watchpoint. Stutters may therefore show up on the Prodn PC's Stage Window, but the Display PC's individual outputs would be ok.


3. If H264 is crashing Watchpoint in the Display PC, try progressively with one output less. You may reach a point where H264 will not crash Watchpoint, i.e. in Production, output to 3 displays instead of 4 and update Display PCs, then 2 out of 4, etc. If such is the case, then you have discovered the performance limit of that particular Display PC.


Thomas Leong

#3 Erik Rönnqvist

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Posted 15 February 2017 - 09:47 AM



Are B-frames enabled in the MPEG-2 videos? If yes, please consider encoding without B-frames. The same goes for h264, you are much better off without B-frames.

B-frames are great when you are trying to maximise the quality for a given bitrate (for example if you are trying to squeeze in as much as possible on a DVD disc), but they increase the decoding complexity quite a lot, as well as increasing the memory requirements for decoding. In practice, if encoding at constant quality, you can expect a bitrate reduction of around 5% when enabling B-frames. You will be much better off if you disable B-frames, and if you are worried about the quality, just bump up the bitrate by 10%. The bitrate increase will have much less impact on performance than using a slightly lower bitrate with B-frames enabled. 

By skipping B-frames, the decoder can decode the frames in the same order as they are going to be displayed, which reduces the risk of stuttering. If using B-frames, the decoder may need to decode several future frames to display a frame, which of course takes time.




#4 Alex Ramos

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Posted 15 February 2017 - 01:40 PM

Yes Thomas ist a capture from the studio. I understand it burns needed resources, it's being used here to simplify the screen capture and I can show all in just one frame.
We don't use this on normal Wachout operation. You
Production PC is as strong guy, i7 5820k, 16GB, 2 SSD, W7000.
The stuttering is not on the production stage or the capture card, is on the display and the resources monitor graphics also belong to the display, that by the way is the weakest of all we have.
I've chosen this specific machine to test the advantage or not of using v6 and HAP vs the v5 and the other codecs.
And seems like HAP can ressurect my weakest machines.
MPEG 2 as proven always to be the best choice but as this specific display reached the limit the option was to replace and move it to a more "gentle position".

I have over 70 display PC and over 100 wachpax on v5 so updating to v6 is quite a sum and must be worthy more than just a new interface as we don't use any of the 3d or mapping functions.
I need indesputable reasons to get the funding.

Yes Erik, on the MPEG 2 GOP15 I was using Bframes, will try it today and post the results of only i and p frames closed GOP.

Thanks for the advice.

#5 Vollmers

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Posted 16 February 2017 - 05:25 PM

Hi Alex
It seems like you have enough power on your PC. My personal experience with the codecs you mentioned, lead me to a decision not using h264 video files. The reason is it have to be decoded and that uses a lot of CPU power. I run all my footage in HAP from a local SSD drive, and my setup is much super stabile now. Just my 10 cents.
Best regards Christian