Compressor and Conversions

Compressor 2 and 3 have very powerful tools for converting and upscaling video, as well as doing slo-mo. The optical flow technology, which Apple acquired when they bought the powerful compositing application Shake (only later to kill it), is the key to the results that you can get from Compressor. The key to getting the best results is the Frame Controls settings in Compressor.

Compressor is very good at standards conversion or converting video to a different frame rate. People often call this PAL and NTSC conversion although this isn't really accurate, but it will handle the same tasks that systems that do this do--namely the scaling and frame rate conversions. Frame rate conversions in particular are difficult to do really well. There are some standalone products from Teranex that just do this for around $2500 Well Compressor does this really well, but Teranex does it in real-time and Compressor is really slow.

Optical flow can also help in up-conversion of interlaced footage. Interlacing makes it really hard to do upconversion because your vertical resolution is basically split in two. For an example of how to scale things up badly look at what Final Cut Pro does in the timeline. FCP basically throws away half of your vertical resolution as soon as you scale a video clip. So the difference between 100% scale and 99% or 101% scale is crisp video and a blurry messy. When scaled up like this over 200%, not unusual when putting in standard-def footage into a high-def project, fine detail like type also starts shaking up and down from the interlacing--it looks ugly.

Compressor is an improvement on how FCP works in a number of ways. First, it can analyze the image and decide to selectively keep detail from both fields when the video isn't moving--if visuals in a part of a frame is moving, then only that part of the frame will lose resolution. With the optical flow technology, Compressor guesses how a part of the frame is moving and intelligently creates an image with more resolution than other results. These two approaches are handled in the deinterlacing settings in Compressor--the first approach is described as Better while Best uses optical flow.

The Retiming controls are where Compressor handles different frame rates. For example going from 25 fps video from Europe to 30fps video over in North America, usually handled as 60i (interlaced) especially in standard-def. The Better and Best settings in Compressor use optical flow. Like with deinterlacing, optical flow analyzes your video and recognizes object and how they are moving--the optical flow then intelligently creates new frames that move objects smoothly without losing detail. By the way, going from 24fps, which is a progressive format, is not a problem for us folks working in 60i. You can do this right in FCP without any fancy conversion (assuming you want to keep the 24fps filmic look.)

As an example, here's what I recommended to someone doing PAL to NTSC conversion:
Resizing: Better
Deinterlacing: Better (motion adaptive)
Retiming: Better
In this case, the scaling is going down (PAL has more resolution than NTSC, so you should get good results without jumping through a lot of hoops.) I reserved the optical flow use to only retiming at the Better setting. I didn't recommend optical flow on deinterlacing to save time. But if time isn't an issue then using Best for deinterlacing should improve results.

Unfortunately, all this intelligent analysis by optical flow is very processor and time-intensive. So for example using optical flow for retiming and and deinterlacing makes my quad-core G5 slow to a crawl--I'd give a ballpark estimate of 1 minute to process 1 second of video. But if quality is important, then the results can be excellent.

There are some plug-ins that specialize in upconversion, namely InstantHD. Check here for my post on upconversion.

Here are two good articles on using Compressor. Macworld discusses standards conversions here that walks you through the whole process:
Send video abroad
This post at Digital Rebellion gives detailed info on all the settings in Frame Controls.
Using Frame Controls in Compressor

The Macworld article also recommends an interesting workflow using Cinema Tools to convert PAL to NTSC by conforming the PAL to 24fps, scaling and deinterlacing in Compressor, then adding pulldown in FCP. Interesting workflow that I've never seen used.

The Retiming controls in Compressor can also give you some very good slo-mo results. Here are some cool tests done that compares Final Cut Pro versus Compressor at various speeds on two shots.
"Final Cut Studio slow motion demo"
"Final Cut slow motion at various speeds"
The author brings up a good point--if you are shooting a shot to be slo-mo, then shoot at as high a frame rate as you can--60p, 60i, 50p, 50i are good, where 24 fps is bad for slo-mo. The more samples per second of the image you can acquire, the better the slo-mo will work.

$500 Shopping Spree

So what would you spend $500 on? I'm soliciting opinions. In another interesting variation, on budgetary outlays, I've been offered $500 to spend on anything I want. The reasoning is that we are charging someone around $500 to make some dubs, and the money can go towards equipment.

Well, after figuring that I couldn't slip a receipt for a Playstation or a 32GB iPod Touch past accounting, I've turned my mind towards more practical purchases.

My number one idea is to replace the tube of the Sony monitor on the A system in Edit 2. Am I the only one noticing that the image is looking greenish? $500 should cover the cost of replacing the tube in that monitor. I'd rather do it now when we have the money--otherwise I'll have to wait around until it is so obvious that the folks holding the purse strings can perceive the bad color on the monitor. That could take a while.

However, I've been thinking about other things too. A few months ago, I was making a big fuss about better production equipment. In particular, I was recommending a new tripod, an LCD field montior and a telephoto lens adapter for the Z1. An LCD field monitor is not out of the question for $500. I wanted to get a high-def one for closer to $1K, but there's a kit for a widescreen one with a resolution of 1440x234 for about $500. Check out the Varizoon kit at B&H. I don't know if this is much better resolution than the Z1's LCD viewfinder, but at 7" it is much larger--ergo easier to see. I've been griping about out of focus shots on the Z1. This should help.

Another idea for production gear is a wireless mic. Anyone recommend a wireless mic for about $500? I doubt $500 is enough for a good tripod but I'd be glad to be proved wrong.

In short, if there's some gear or software that you think would really help our work at Link for $500, please let me know. Please leave your suggestions in the comments sections--that'll let other see your suggestions and allow them to rag on them. Oh, and it's got to be near $500 or under $500--no $500 towards a new computer or something. No saving for a rainy day here--when you've got it, you spend it.

Summer Blogwad

I'm just dumping some interesting links here to check out.

Digital Rebellion: Recommended QuickTime and Mac OS configurations for Final Cut Pro
A list of recommended combos of FCP, Quicktime, and OS versions. Let's just call this why not to update your systems unless you absolutely need to. On the other hand, it sucks being caught in FCP 5.1.4 world while everyone else has moved on. That's more of a money issue than a technology issue though.

Digital Rebellion: List of QuickTime downloads
A continuation of the theme of don't upgrade if you don't have to. If you have to upgrade but it's not to the latest and (ahem) greatest, then this page will help you find the appropriate upgarde for QuickTime. Similarly, the LAFCUP has a wiki page on Quicktime updates.

Little Frog in High Def: APPLE PRO APPS UPDATE 2008-02
Good advice on downloading all updates to Final Cut Pro even if you don't intend to upgrade. The reason is that Apple doesn't make old updates available for FCP (unlike QuickTime). There are situations where you might want to upgrade but not to the latest version--if you don't have the update then Apple isn't going to help you. You can download updates through Apple's Final Cut Pro page--you don't have to upgrade through the Software Update control panel.

Final Cut User: Using FLVs in Final Cut Pro
Some good tips on using video downloaded from the web from sites like YouTube. I didn't know about using the QuickTime wrapper to help the editing of FLV's--sound like a helpful tip.

"Ten Tips For A Better Final Cut Pro Experience"
This is a good read. An experienced editor wrote down 10 good tips. Good write-up on media management. Also some interesting tips on multicam, amongst a number of other good ideas.

kenstone.net: Color Workflows With Different Types of Sources
By Andrew Balis
Want to work in Color? This seems like a good guide for getting footage in and out for your next go as a colourist.

Overview Video on Sony EX3
I don't think I've talked about the Sony EX3 because I think the MSRP was over $10K and that's my cut-off point for talking about cameras. But it lists for under $10K, and it looks like a good upgrade to the Sony EX1. I've been hearing about and seeing folks use the EX1. Seems like the XDCAM format on SxS memory cards could take off.

ProLost: On Clipping, Part 1
Very tech-y. But interesting to get a theoretical understanding of how video works. Folks interested in Red should read. It helped me understand why there is more grain in dark areas of video than in light areas. Also discusses important differences in how film and video represent light.

ProLost: Go Naked pt. 2
A good example of the guerrilla filmmaking model as described in Stu Maschwitz's "The DV's Rebel Guide." More interesting to me is that Vimeo not only streams HD, but allows downloads too of Quicktime movies (the film shown is downloadable at 1280x720). You can upload up to 500MB per week to Vimeo. An interesting way to share footage encoded in h.264--nice that it allows both streaming and downloading.

stockfootageforfree.com
Not awesome but could help in a pinch. I did about 10 searches on foreign countries, and the only video I got was touristy stuff from Cancun. Some OK shots of D.C., SF, and NYC. [via freshdv.com]

Streaming Video: Quality Comparison and Trends

There's a pair of interesting articles about streaming video at Digital Content Producer:
Encoding Best Practices, Part 1
Encoding Best Practices, Part 2

Part 1 is a report based on samples of what kind of streaming video is out there on the web. It's not a huge sample, but he does look at about 20 sites from broadcast video. So that's a good comparison for Link. Flash and Windows Media far outpace any competitors, like Quicktime and Real. One trend in streaming is growing bandwith and image resolution. Most broadcasters were streaming at a frame size of 460x325 and at a data rate of 500 kbps. Lots of good charts showing trends on this as well as frame rate and audio bit rate.

Part 2 is a quality comparison of h.264, on2 vp6, and VC-1 (Windows codec.) VC-1 gets the lowest marks. Both articles are interesting reads. I found them over at FreshDV.

Troubleshooting with Activity Monitor

Recently Activity Monitor has been instrumental in troubleshooting problems for me. Activity Monitor is part of the Mac OS and lives in the Utilities folder, which is in the Apps folder. It gives you read-outs on things going on with the computer, including what the CPU and RAM are doing.

Here are a couple of good descriptions of the RAM display in Activity Monitor:
Final Cut Studio - System Memory Usage--Larry Jordan's Tip of the Day
Mac OS X: Reading system memory usage in Activity Monitor--Apple Support

The two pages actually give somewhat contradictory advice. Larry Jordan says that if your wired and active memory is regularly half of total memory then you could benefit from a RAM upgrade. While Apple says that even if you only have 10MB of free memory you don't necessarily need more RAM.

I've been noticing some bad examples of slow FCP that I blame on memory issues. So I think it's important to keep track of your RAM issues. Here some tips to keep your RAM usage streamlined and efficient:
- If you don't plan to switch back to an app, quit it and don't leave it open
- Avoid running multiple apps at once, especially programs that can suck up memory, like FCP, DVD Studio Pro, After Effects, and Photoshop
- Only keep open FCP projects open that you need, same things with sequences
- Restart your computer at least once a day and if your system seems really slow then restart it
- Web browser and webpages can use a surprising amount of RAM--avoid browsing with lots of windows/tabs
Now all of these RAM saving tips can reduce your efficiency in working. So it's a tradeoff. If your system zips along fine, then don't worry about it. But if you notice that your system starts the day zippy and ends up later trudging along, then try to follow some of or all of these tips.

I also uncovered a problem recently with Mosaic where the Mosaic project file had become huge even though there didn't seem to be that many clips or edits in the project. The size of the project file can give you an idea about how much memory an FCP project will take up in your RAM and how many resources the computer will use to work with the project. I'm not really sure why the Mosaic project file got so large--over 300MB. But I think it hurt that the editors were just adding stuff into the same project file day after day--even if they were deleting old clips and sequences regularly. I think the Mosaic project seems to have retained data from old clips and/or timelines that had been deleted and didn't appear in the project view. So I created a new project and just copied the timeline and clips that were visible in the project window--the new project was something-like one-tenth of the size, and the system got much quicker. I also read recently that clips that are really long are more taxing on the computer than more shorter clips that have the same amount of media.

Another things that Activity Monitor does is measure CPU usage. This was helpful recently when I was having problems with the single processor G5 computer. An intern was having problems capturing DV footage from a DV deck. I had set up an unusual firewire cabling setup, so first I tried changing that--no luck. Then I brought in a different deck. No matter what I did, I was still getting dropped frames and funky audio dropouts. I noticed that the intern had Firefox running, which I didn't think was I big deal--she was checking her Gmail. Then I opened up the Activity Monitor and I saw that Firefox was quite active. It's CPU usage was hopping all around, peaking at up to 15% of the computer's CPU usage. And it wasn't even like she was actively browsing--that's was up to 15% of the CPU just to keep up with Gmail. Well I quit Firefox and the computer started capturing fine and did about 5 hours of capture with no problems.

Now I'm lucky to have a four-core G5, and I regularly have multiple webpages, email client, and even iTunes running all while I capture from DV. But for a single-processor G5 the demands of running FCP, capturing DV, and having Gmail open were too much. So it is important to know your computer. Also remember that laying off is at least as demanding on your system as capture and almost always much more. You are almost always playing back multiple clips at once (remember all your audio tracks) and your system is probably trying to apply some real-time effects to the video and/or audio. So be even more conservative about what your computer is doing when you lay off to tape.

BTW, I recommend Larry Jordan's Tip of the Day. I don't want to visit his website everyday, so I subscribed to the RSS feed and check out the tips when I have time.