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I need help figuring out how to record while my computer is rendering.

I am very new to video editing, so this is my current workflow. First, I record footage using Fraps (30 fps, 1080p, .avi). I usually get several hours worth. Then I use Adobe Premiere CC and Media Encoder to cut the video into 20 minutes chunks. I queue all the videos up in Media Encoder (h.264, mp4, 1080p, 30fps).

Each video takes about 30 minutes to render (intel 2600k. dual amd 6950s, 16 gb ram). My source video is on a 2 TB HDD and the destination is a separate 1 TB HDD.

Here is my problem. While rendering, the computer can't be used for much else since my CPU usage is capped. My GPU doesn't seem to be used at all (as I understand, h.264 encoding is almost all CPU based).

How can I change my setup so that I can record more video while the machine is rendering away? In addition to my PC, I have a NAS available, a Macbook Retina Pro (2012, 16gb ram), and two external HDD cages. I think I need to come up with a setup where I can record on one machine and render with the other, but I don't know if this is viable or which HDD to record video to in that situation (is recording to NAS common? or do I make the other computer's HDD a share drive? record to external drive and move it around?)

There are a lot of unknowns for me here and I would just like to know what a "normal" setup is for using one computer to record and another to render. I am on a gigabit LAN with my NAS and laptop, but the laptop only has wireless connectivity.

I would just render my videos over-night, but that is when I upload to Youtube, as that takes many hours.

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    h.264 encoding is almost all CPU based - A CUDA-enabled GPU can greatly ease the load on the CPU, if the encoder supports it. I see CPU go from 100% to 40% when using an nVidia gfx card on my PC. – Jim Mack Nov 23 '14 at 11:13
  • Interesting! I have AMD cards, but the OpenCL rendering doesn't seem to have any effect unless I load the video up with effects, fades, color shifts, etc. – Joshua Powers Dec 9 '14 at 22:19
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Don't, just don't. File access is your primary problem. You can offset this by using SSDs, but the much more practical solution is to either upgrade to gigabit connectivity between two systems or use high speed external drives to move content captured on one system to the other system and then run the encoding completely distinctly.

Capturing footage on a system running a game is already a very difficult thing to do as both the file capture and the game engine put a lot of demand on the system. Adding a third major demand of system resources is asking for trouble. The main reason that files are so large from video game screen captures is that very little compression is applied. Video games don't use much disk resources (outside of loading levels) but they do use a lot of CPU and GPU. So screen capture tools for games put off CPU and GPU intensive tasks at a cost of disk utilization.

The problem is that encoding is going to make use of both disk utilization and CPU and GPU resources. The CPU and GPU utilization will interfere with the game engine and the disk utilization will interfere with capture unless they are on a completely separate pool of resources on a different machine. It is possible to segment resources off in some cases, but you'd still be substantially impacting the capability of your system and reducing the quality of capture and gameplay it could achieve.

  • Thanks, this did the trick, specifically, external drives. I ended up using a WD Caviar Black over a USB 3.0 external dock. This is fast enough to write lossless 1080p video to. Even better, my MacBook Pro has no problems reading from it and rendering it. So my workflow is to record to the external drive and render on the Macbook. – Joshua Powers Dec 9 '14 at 21:39
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I assume you record video game footage? Recording and rendering on one machine is something I wouldn't recommend with a regular PC if you play modern games that take a lot of your CPU and GPU resources.

I usually recommend getting an SSD but in this case it seems you are heavily CPU limited. You could theoretically encode on the GPU but I'm not sure if that will ease the workload all that much to be able to play games as you need your GPU to play games aswell and usually GPU encoding produces worse results than CPU encoding because of the way the codec is implemented for GPU encoding.

What I would do in your case is either render on your MacBook, rendering over the network shouldn't be too bad in this case as your MacBook will be CPU limited aswell. Or you don't do the final encode of your videos with Premiere/AME but use a different h264 encoder called x264 which is a LOT easier on the CPU and with the right settings could potentially used while you play games. x264 is by far the fastest and most efficient h264 encoder today.

You would first render your cut videos in a lossless codec that doesn't takes very little CPU usage but be sure to not render to the disk that your game runs on, as a lossless codec will be very I/O heavy.

Alternatively if all you do is cut your videos in to 20 min pieces without any other creative decisions other than splitting up your videos at every 20min interval you could automate everything and ditch Premiere all together and just use FFmpeg which also integrates x264 so you can cut your videos automatically there and encode to h264 all at the same time.

You could theoretically also upload automatically after rendering if you are bit into programming and do all at night without supervising anything. That would free your pc up for recording during day. That can of course only work if you don't already need all night to upload the encoded videos.

There might be more viable solutions to your problems but that would need a bit more info from you. What do you record? What are you doing in Premiere exactly to the videos other than cutting? What are the specs of your computer?

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    Recording 1080p 30fps directX / openGL video with i5 2500k. 3 SSDs and 2 HDDs, no RAID, wireless n. Now I did end up trying x264 and it is actually quite good, but I ran into problems with both premiere and final cut pro not being able to correctly edit the footage (the colors were strange). I ended up just recording lossless data to an external drive over usb3, it ended up being more than fast enough for 1080p 30fps using whatever codec FRAPS uses. – Joshua Powers Dec 9 '14 at 21:42
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Blackmagic Design has solutions for this. One is a live H.264 encoder ( https://www.blackmagicdesign.com/products/h264prorecorder). This is commercial equipment though, so it's going to get expensive fast.

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