Video compression has come a long way from the days of using Cinepak on a Quadra 950 tower and the old NuBus slots. For the most part, the wars between online formats has been settled with Flash leading the way. But behind that Flash Player is often H.264 encoded video, ever since it was introduced with Flash 9 in December of 2007. Even video powerhouse YouTube is pushing out H.264 video wrapped in a flash player. If that’s not enough, one of the officially supported video formats for Blu-ray is H.264.
So from on-line video (SD or HD) to high end Blu-ray DVD’s, h.264 is a huge player. It’s all good, right? Well, mostly. Have you ever compressed an h.264 video file? It can be unbearably long. We first started running into this bottleneck when we switched from doing mpeg-1 client web approvals (something that was very fast to compress and widely compatible) to h.264. We switched mainly because we wanted to post high resolution web approvals for our clients at higher quality, and MPEG-1 just wasn’t cutting it. H.264 really filled that need. But even a shorter video, say 10-15 minutes could take 60-90 minutes to compress on a Quad Intel MacPro, and some of our videos are more in the 30 minute range. If you have the time, leaving it running overnight is no big deal, but most of the time we’re doing these web approvals close to 5 or 6pm and they needed to be posted and sent to the client that same day. Waiting around just to finish a web post feels like a waste of time (although we did minimize this to some degree using LogMeIn as covered in my previous post).
After hearing others brag about how great it was, we finally decided to try the “to good to be true” Turbo.264 USB key from Elgato (the non-HD version). I really fought it because I had a hard time believing that a little USB key could do what my huge expensive multi-processor MacPro could not. But also because it did not integrate with Compressor, which is part of our workflow. For the price though, we decided to give it a try.
For what you end up paying, the Turbo.264 does a pretty good job. It is FAST for sure, and the output is not too bad, but it’s not perfect either. It gave us the speed that we wanted, but not the quality. One of the main reasons it’s able to do what it does so fast is that the very first thing that’s done is resize the video frame, and then pass it off to the USB key for processing. This is key, because the rest of the processing is done on a lower resolution frame instead of working with the original uncompressed frame. Great for speed, but not optimal for quality. But for many people, this might just do the trick depending on your needs and budget. You end up seeing compression artifacts in places that you wouldn’t when using compressor with similar settings, typically areas of fast movement, effects or dissolves. But it did take care of the time bottleneck that we were having. So we decided to sacrifice some quality for the sake of actually getting home on time but continued to look for other options.
Then I read a press release about a new product from Matrox called CompressHD, and I had a warm and fuzzy feeling all over. I contacted Matrox and asked them if it was possible to get a review unit and they were nice enough to send it out a week later. While it’s 4-5x the cost of the Turbo.264 USB key, (depending on which one you compare it to, the first SD key or the more recent HD version) it has some great benefits that make the cost worthwhile. I’ve been using it for nearly 2 months now and it has taken the pain out of h.264 encoding.
Installation is easy, but for most editors the biggest problem may be finding an open card slot on your MacPro. We decided to sacrifice a SATA card to make way for the CompressHD card. All it needs is a PCIe slot. Once installed I started the computer and installed the software, and after a quick reboot it was good to go.
Integration with Compressor
The biggest selling point (aside from the speed) is the seamless integration with compressor. Inside of compressor there is a new preset folder called “Matrox MAX H.264 Settings”. If you take a look at what’s inside, you’ll find that the presets are very similar to what you’re used to seeing in the Apple Settings.
If you’re used to using compressor, not much changes in your workflow for creating h.264 files. You pick one of the Matrox presets that fits your needs, apply it and submit just as you did in the past. However, much of the processing is now handed off to the CompressHD card. The only thing handled by compressor now is the decoding of the video frame, everything else is handled by the CompressHD card. The card has 2 processors that are optimized for different functions. One chip handles resizing/scaling, and the other handles the color space, compression and output. So what you end up with is this nice little video assembly line and each frame is passed from chip to chip to perform it’s designated function.
But what if you don’t want to use one of the presets included? What if you have specific needs of your own? No problem! You can create your own settings and still take advantage of that nice processing power. As an example, here is a setting that we created to use for web approvals.
What is the difference between the Apple h.264 presets and the Matrox ones? Nothing really. The Matrox folder was created for convenience and to streamline your experience. You can choose any of the Apple h.264 presets and they too will access the card.
If you want to compare performance with and without the card, there’s no need to pull the card out and then put it back in. Open up the control panel and you can turn the card on and off. This is what we did for the comparison tests. We’ve been running version 1.6 of the software, but the current version is 1.8 and is now Snow Leopard compatible. However, we’re still using Leopard and do not plan to upgrade until sometime late next summer.
Once we got this card in the machine, we just couldn’t wait to start compressing something… ANYTHING, just to try it out. It’s not that compression is all that interesting, but I really wanted to see how this baby performed. It was like dropping a new engine into a used car, we just wanted to hear the engine fire up. Here are the details on how we tested the card.
All tests were performed on a 3.o ghz Quad Core Intel MacPro with 12 gigs of RAM. We ran each compression twice. Once with the CompressHD card enabled, and once without. During these tests there were no other operations being performed on the machine, but only for the sake of making sure we were comparing apples to apples when we got the final numbers. One of the main reasons to use this card is that it handles so much of the work load, you can continue to work and even do processor intensive functions on the computer while having little or no effect on the compression times that the card puts out.
We used version 3.05 of compressor, that is part of Final Cut Studio 2. If you’re running the latest version of Final Cut Studio (we call it 3 because Apple forgot to give it a number) you will already have the ability to create Blu-ray movies within compressor. In our case, the card actually adds that ability to compressor, since this version of compressor does not directly support Blu-ray (only the now dead HD-DVD standard).
Our test video is 14:12 long and in 720p format using the ProRes 422 codec. The original file is 7.85 gigs in size, and we compressed it to 6 different formats as part of a single batch for each of the tests. We chose some of the most common presets that we might use, as well as one custom one that we use in house.
Here are the results.
As you can see, there is a significant difference with the card enabled. There’s something very satisfying about watching it crank through the data so fast. It does however cut down on the coffee breaks and long walks on the beach.
One thing that I noticed is that the biggest benefit comes when you are changing resolution. This is where having the dedicated hardware really pays off. When you’re simply just converting from one format to another (say ProRes to h.264 with no other changes) the speed bump is less noticeable, but still there.
As an example, look at the Apple TV bar compared to the iPhone bar. Because the frame size for Apple TV does not need to be changed, the card just passes the frames through at the same resolution. But for the iPhone version it has to be scaled down a lot, something that the card does much faster and with better results then just using compressor.
*NOTE: You might have noticed that the Blu-ray bar is the same on both passes. Because I was running Compressor 3 instead of the newer 3.5, Blu-ray is not supported natively. So on both passes, the CompressHD card was used. So kind of pointless for our purposes, but I left it in anyway.
The image quality is as good as anything coming out of compressor natively, but at a fraction of the time. In all of the tests that we did I couldn’t see a quality difference between using the card or not. Compared to video run through the Turbo.264 key, there was a noticeable difference. Again, I’m not totally knocking the Turbo.264 product, it does have its place. I use it all the time to convert movies/tv shows from the TiVo format to iPhone so that I can watch them while at the gym. But for trying to exceed the expectations of my clients the Turbo.264 key falls short. We’ve also had problems with it dealing with anamorphic footage properly without having weird scaling and cropping issues.
One thing to be aware of is that the CompressHD card will only do CBR compression, not VBR. Not a huge deal, but something to be aware of. This is also a limitation of the Turbo.264 usb key. VBR adds a much better quality to file size ratio then CBR, but in my experience this is not much of an issue. Disk space is abundant, the internet is fast and both SD DVD and Blu-ray can hold plenty of data. Not a huge deal.
Just to give you an idea, here are some file size differences based on the same source video.
One of my original concerns was that the card might interfere or conflict with other capture cards from AJA or BlackMagic, but it plays nicely. The codec’s that Matrox wrote are based on the Quicktime Component architecture built into QT, so any hardware or software that supports the implementation of QuickTime Component will work just fine.
Matrox Product Integration
It’s worth noting that you can get the CompressHD hardware (called the “MAX“) as part of some of the other Matrox products. For example, you can purchase a MXO2 and get it outfitted with the MAX card for just $400 more, saving you a $100 over buying the card separately. One of the great benefits of this is the ability to run this type of hardware on a laptop that has a Express34 slot, instead of just a tower. One of the down sides is that you can’t use both the MXO2 Max for editing/monitoring while the hardware is compressing. It’s an either/or situation. But for many that will be a small trade off for the ability to take this mobile.
At a street price of $499 the CompressHD is not exactly cheap, especially if you only occasionally need to compress to h.264, and time is not an issue for you. But if you encode as much as we do and don’t’ want to spend your whole week watching a progress bar, I would whole heartedly recommend getting the Matrox CompressHD. It’s a solid piece of hardware that integrates nicely with the FCP workflow so seamlessly you will forget it’s even there. That is, unless somebody takes it away from you.