When it comes to maximizing your editing efficiencies, especially when it comes to 4K footage, you have to look at two key factors- the recorded size of the footage you are gathering (compact camera original or much higher “production level” data rates) and the specific processes you use when editing. By carefully choosing or adjusting how you do things, you can save thousands upon thousands of dollars, while also ensuring your edit workflow doesn’t get bottled up.
4K IS NOT TOO BIG:
Editing 4K footage really depends on the camera you use and how you intend upon editing it. For instance, I have the Panasonic GH4. It shoots 4K footage. But the data stream for 4K is about 10 MBytes/s. Just 10. If you don’t have a hard drive system that can do 10 MBps, a single hard drive- FireWire, USB-2 – you definitely need a new computer.
But realistically, most any computer these days can handle a 10 MBps stream. If you’re taking your 4K footage and you’re expanding it into ProRes or DNxHD or some other editable codec then, yes, your data rate will be higher and other constraints come in the play. All that comes in the play are going to focus on editing for K footage in a camera original format. In this case with the GH4, it’s a H.264 codec with a max of 100 Mbits/s. It actually only averages about 80 Mbits/s which is 10 MBytes/s.
Editing yet a high bit rate codec, or all I-frame codec, enable older systems to handle the footage easier but today’s systems are much more capable– especially when you leverage the GPU. That’s really what I going to talk about today. I am going to be using Adobe Premiere “Creative Cloud” and I’m going to be editing GH4 footage natively. In my timeline with 4K footage and I will be applying a lot of filters and doing different things. I want you to see what you can do with native codec images on a current system. You don’t have to invest in the latest and greatest. The system I am using is available for under $1000. So let’s see what we can do.
UNDER $1000? YES.
Let me tell you little bit about the system I’m editing with here in my studio. I have a dual-screen setup on a dedicated desk. I have an Nvidia GTX-760-based Alienware X51 “gaming” computer. The video card was the key component of this system because I’m going to be editing with Adobe Premiere. Premiere is going to leverage the GPU, the video card, for video editing. It’s a 8-core i7 CPU processor. It has a Blu-ray player, UBS-3 on the front and back.
It’s sort of a small form factor PC in that there’s no extra room inside. So I can’t put another expansion card, of any type, in the case. It is the way it is when it comes from Alienware. I went with a pre-configured system because this was my first Windows PC purchase. I don’t have the background or the knowledge to know what motherboards work well with what RAM, what CPUs, what GPUs, the bios and all that.
People say, “Go build your own PC.” Heck you could build your own house if you wanted, but that’s not what I do for a living. I shoot and edit video. I’m not a computer builder. I know what my limitations are. I don’t try and build computers so I bought one.
I have my computer set up so that my editing interface is on one screen. On the second screen I have my program monitor so I can see it at full 1080. I have Premiere set to show me “full” quality, not 1/2 or 1/4. Although those options are just a click away. When I click play in my timeline, and I’m watching a 4K clip, it plays smoothly on this computer.
Actually, the video that is being played is not on this computer. It’s not on a RAID system. It’s not on a SSD drive. The clip is being played back over the network from a 2-drive (mirrored) NAS. In this case, it’s the ioSafe 214. It’s a fireproof, waterproof system set up for redundant storage so my client footage is protected. It’s shared over ethernet not just to one computer, but to all the computers on the network, at gigabit speeds.
The footage I’m editing with is directly from the camera. This is H.264 set at the 100 Mbit/s data rate. But I find that the footage the camera records typically is at 80 Mbits/s. 80 Mbits/s divided by 8 is 10 MBytes/s. My ethernet connection can do well over 10 MBytes/s. When I test it with CrystalDiskMark I get over 60 MBytes/s write and over 100 MBytes/s read from the NAS. Definitely more than capable enough to do 10 MBytes/s.
The added advantage to using a NAS is that I can access everything from any machine in the office. It’s accessible to everyone. Now, multiple people trying to access different clips at the same time from the same spinning platters will slow down everyone’s access and result in choppy playback. But, for me, this works fine. I can export a finished video into the project folder and immediately access it from a different computer for e-mailing or posting online.
I hear all the time that you need to have a massive system to edit 4K. By using Alienware’s included performance monitoring app, I will show you in real time this computer’s performance metrics: CPU use, GPU use, RAM use, Networking speed and more. When I click play in the timeline and watch my 4K clip, I can see the CPU cores loafing along at 40-50% and the GPU pretty much not at all. So I’m not really taxing this system at all by playing 4K footage in Premiere.
Now, it’s obvious that I’m not actually doing anything with the footage yet. So I’ll add a three-way color corrector to adjust the image. Then I’ll add a Fast Color Corrector and an oval mask to act as my overall vignette. Then I’ll add a sharpen filter to 10%. Now I’ll add a horizontal flip. Then a crop filter and bring in all four sides and feather the edge. This is on top of the Motion filter scaling the 4K clip to 50% to fit into the HD frame. I’ll add a Timecode filter on it and make that big and easy to see.
The key thing that I’m doing when I use these filters is that I’m selecting from the accelerated filters. These are designed to use the GPU as opposed to the CPU. Now I’m going to add some Noise. I’ll make it grayscale and it’ll look like film noise, or “grain.” So I’ve added seven filters on top of a resize and downscale of the entire clip. Then, when I click play on this clip, we can see that NOW the GPU is being pushed to near 100% utilization. I can see it’s dropping a few frames, and that’s probably because of the noise filter, which I typically don’t use, pushing everything past what the GPU can handle.
Meanwhile my CPU is still loafing along at 60% utilization. Even with all these filters on top of the 4K clip. Are you really going to heap on all those filters, onto every single clip in your video? Probably not. Nevertheless, the video that accompanies this article demonstrates that you can do all this with a basic, under $1000 system, if you choose your filters wisely. I learned this key point the hard way.
I used to use a Generate filter, with a Circle, to build my vignette. This is not an accelerated filter and if I add the Circle filter to the video, the render bar in the timeline immediately goes red. This means that Premiere knows that it can’t be done in real time. It’s not going to be a GPU-assisted action and the CPU will have to try and do everything. In the video you can see with nothing more than a single little white circle visible I completely maxed out all eight cores at 100%. At the same time- my GPU utilization is ZERO.
When I invert and feather the circle so it actually allows the video underneath to show through, you can then see that my playback is extremely choppy, despite pushing the CPUs as hard as possible. The key is that I added one non-accelerated filter. And suddenly, the system simply cannot do it in realtime. That makes all the difference. Choosing the right process that are designed for acceleration lets you maximize the effectiveness of a less expensive system.
As soon as I disable the Circle filter, the render bar goes yellow again, meaning that Premiere will do its best to make it happen in real time by using the GPU. It’s still a bit stuttery because of all I’m trying to use. I can mitigate that by adjusting Premiere to show me the video at less than 100% quality. You can quickly toggle video playback to 1/2 quality, and when you pause, the still image will be at 100% When I toggle this heavily effected clip to 1/2 quality, the playback becomes smooth.
Not only is the playback smooth, but now my GPU is not being pushed to 100%. The GPU is down to 40%. CPU use is unchanged around 70%. By staying within the constraints of what the computer can do, I can get smooth 4K (with seven filters heaped on top) playback on a less than $1000 computer, playing footage coming across the network from a NAS. It’s not coming off of a RAID, or a solid state drive, or some other expensive storage system.
You don’t need to spend over $5,000 for a high-end, kick-ass workstation. You don’t need to spend $3,000 on a big, multi-drive RAID using Thundrbolt-2. You don’t need these things to edit 4K footage- with two caveats:
1- Keep with camera original footage.
And by this I don’t mean high-bitrate ProRes or DNxHD. Not CinemaDNG. Not RAW. Those are high-end needs. I’m talking about mid-range systems- corporate setups, where we need to ingest, edit and export footage expediently. Also, you’re not using a ton of HDD space because you are keeping with a much lower nitrate camera original codec. In this case, that’s an 80 Mbit/s file for 4K footage.
2- Stay within the optimized capabilities of your edit system. For Premiere- this means the accelerated filters.
When I have seven filters on top of a 4K clip and it plays smoothly and effortlessly, you can them see the value of choosing GPU accelerated filters and effects over choosing something that’s not accelerated. When you choose something that’s not accelerated, you’re not going to get smooth playback for that element until you render it.
Now, if you need to do that for specific clips: here I’m going to use a denoiser, over here I’m going to use the Warp Stabilizer, etc. Those you ave to render. Then, once rendered, the edit software plays the render and doesn’t have to try and compute the effect in real time. Your playback will be smooth.
Once you understand these two caveats, to editing 4K footage affordably, then you can minimize your editing time, spend more time delivering finished content, and less time waiting for your computer. You can save a lot of money and still get the job done. In the end, it’s about getting your footage in, edited, and back out.
Are you making a feature film? Well then you can worry about the highest quality image acquisition. Otherwise, focus on the turnaround, the return on investment, focus on working efficiently. And also, by staying with a camera original codec, your long-term storage needs go down as well.
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