From the course: Video Gear

Capturing uncompressed video onset

From the course: Video Gear

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Capturing uncompressed video onset

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- So obviously, Rich, on a lot of cameras there's a lot of high compression going on. Everything from H.264 to MPEG files to even proprietary formats. There has been a trend, I would say, over the past five to seven years, that started in the high end and has made its way down into more affordable cameras, and that is the use of what I would refer to as less compressed or editing friendly or lower compression type codecs. And what I mean by that, Rich, is formats like Apple ProRes or Avid's DNxHD. These are still technically pretty compressed signals, but in nature of how they work, with I-frames only, that is, every frame is a frame and high color sampling and high bit depth. Even though they're compressed, they are much better quality and more apropos for something like green screen shooting than you would get with something like H.264, for example. - One of the reason why these high-quality codecs are not often enabled in-camera is because it creates a lot of performance issues. Both because we have storage limitations and size capacity. I mean, show me a DSLR where you can shove a full-size SSD in. It just doesn't exist. And so, we're dealing with all sorts of issues, from performance, to battery life, to heat, to form factor. So this is often something that has to get put outside. What we're seeing here, for example, is we're taking the HDMI output from the Sony a7S into the external recorder. And internally, this camera can't shoot 4K but with this, it can. - Yeah, so internally we can do a couple different flavors, AVCHD and Sony's own formats and different log flavors and things of that nature. But you're right, Rich, we're pumping out HDMI here, and this is an Atomos Shogun. This is a new 4K recorder and, by the way, this is not just a recorder. This is actually a high-quality monitoring device, as well. We can do things like false color and focus assisting. We can do things like bringing up scopes. This is a really essential piece of kit, or other recorders like it, for doing what you're suggesting, Rich. That is, pumping out signal from the camera to the recorder. Now, there's one really important thing that we should mention. Depending on your camera, you may or may not have a clean way of getting signal out of the camera. Now, Rich, that used to be a huge problem in the early days of the DSLR revolution, where you'd have things like the record button and frame guides and a lot of kind of stuff on screen. - And they told us that could not take it off and import taxes and all these crazy rules, and things like Magic Lantern came out to hack this. But now just about everybody's okay with this idea of clean HDMI output. It's sort of become a standard on most cameras, which enables this. - Right,and these recorders are going to be pretty flexible in terms of their formats. Now, the biggest ones or biggest formats or most popular formats that you're going to see: ProRes, DNxHD. Some of the recorders will also allow you to do things like CinemaDNG, which is sort of an open-source, kind of raw format, if you will. But as a whole, ProRes, DNxHD kind of rule the roost and you're able to record, in most cases, in different flavors of those codecs. For example, with ProRes, you could go from anywhere from ProRes Proxy and LT, up to ProRes 4444, for the utmost quality. - And, if we're using some of the professional decks, for example, in the studio here, we have some decks from Blackmagic. We could take an SDI output from one of the cameras, and run it to a full-size deck that truly can capture uncompressed video. - And I have one even better for you, Rich, you could actually use your computer for that purpose, as well. If you're running software like Premiere Pro or Final Cut Pro X or even DaVinci Resolve, you can do live capture to a variety of codecs directly on your machine, assuming that you have fast enough storage and enough storage on your computer to do that capture. Of course, that would require some sort of IO device to your computer. But as we've seen in previous episodes, that we've talked about things like Blackmagic UltraStudio Mini Recorder, devices like the-- - $150 and you get capture on a laptop. It's awesome - Really, really easy to do. Now you mentioned uncompressed. What does uncompressed mean? - If you say uncompressed, it depends who you're talking to. So, from a strictly engineering standpoint, there are uncompressed codecs. If you're using a fast enough recorder with things like SSD memory cards, you can actually capture uncompressed, which is fantastic. But, of course, there's also lower compression codecs. For example, if you're shooting ProRes 4444, or something with a 200 megabits per second type data rate, well, it's still compressed but you might not even see it. - Yeah, there's a difference between having the signal being technically uncompressed and it being visually lossless and kind of being perceived as uncompressed. That's why formats like ProRes and DNxHD are so popular, because they have relatively low data rates, they're not very big files but visually they pretty much look uncompressed. But you're right, an engineer will tell you, "Nope, nope, nope. That's very heavily compressed." There are, of course, eight and 10-bit uncompressed formats, in addition, depending on your recorder or the device you're using, you could record into a format like Cinema DNG, which is essentially a raw format. Depending on the recorder, as well, you could do things like image sequences, like DPX and TIFF image sequences. So those workflows do exist and in the context of doing a green screen shoot, you might want to explore those options. But, I think for a lot of practical purposes, if you go into it with the idea that, hey, production or edit quality codec like ProRes or DNxHD, at one of its better flavors, that's going to give you, in most cases, much better results than recording something like H.264 to a camera. - Yeah, so let's head into an edit suite. We're going to show you some different flavors of footage that we've been capturing for the last couple of weeks, and we want to show you how those hold up when it comes time to key in.

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