Preparing Video for Transana
Perhaps the most common question about using Transana effectively is how to convert your video (which could be in any one of a variety of analog or digital formats) into a digital video file that Transana recognizes, ideally MPEG-1 or MPEG-2.
While Transana can handle several different video formats (and the list of formats it can handle is likely to grow), we recommend that you try to use MPEG-1 or MPEG-2 if at all possible for a number of reasons.
We recommend MPEG video because:
- Transana was designed to use this format;
- It is a non-proprietary, cross-platform standard;
- It has good compression rates;
- It has hardware available for real-time analog video capture/compression; and
- It has lots of third-party software, including open source software, that handles these formats.
But you might wonder which compression standard, MPEG-1 or MPEG-2, is the best format for your work. MPEG-1, in general, has smaller file sizes (about 650 MB/hour) compared to MPEG-2 (double that and more) but reduced detail (MPEG-2 has roughly four times the resolution of MPEG-1). Here are some rules of thumb to consider when you think about video compression formats:
- Close-up shots of subjects
- Smaller number of subjects
- Less movement of subjects/camera
- Less emphasis on analysis of visual detail
- Wide-angle shots
- Larger number of subjects
- More subject/camera movement
- More emphasis on analysis of visual detail (e.g., eye gaze, legibility of chalkboard, etc.)
What about MPEG-4?
MPEG-4 is a newer standard for video compression formats with more flexibility and potential for future expansion than either MPEG-1 or MPEG-2. Most of the forms of MPEG-4 we've seen appear to produce equal or better quality video with the same or smaller file sizes. Chances are good that this format will eventually surpass the earlier forms of MPEG. Unfortunately, because there are differences (incompatabilities) in how the two main operating systems (Windows and Mac OS X) implement the standard, because of lingering questions over licensing for the format, and because Transana's ability to handle this format on all platforms is still unclear, we can't wholeheartedly recommend this format.
If you absolutely must use this format, make sure you research it thoroughly and try to find a cross-platform version, such as 3ivx (though it is a commercial product). We'll try to provide more information about Transana's ability to support MPEG-4 as we continue development.
Video Compression Solutions
There are three possible situations you can find yourself in, based on what kind of video you have, and there are three different approaches to getting your video ready for Transana.
Here are the three different kinds of video you could have:
- Analog video: VHS, SVHS, 8mm, Hi8, Betacam, and other formats that come from analog video cameras.
- DV video: Mini-DV, DV, DVCAM, DVCPRO, and other formats that come from digital video cameras
- Computer Video - AVI, Quicktime, RealMedia, MPEG-1, MPEG-2, MPEG-4, and other computer-based video formats.
With analog video, you're often faced with two tasks. First, you need to get your video onto a computer, and second you need to get it into the right format. You use a video capture card to get the video onto your computer. These cards can range from simple and cheap systems for around a hundred dollars (for instance, Pinnacle Systems' line of home video capture products) to extremely expensive broadcast quality systems costing thousands of dollars. The rule of "you get what you pay for" applies here up to a point; after about $400-$500 there are diminishing returns for research video purposes. Here are some points to consider:
- There is a subset of capture hardware that can capture your analog video and convert it directly to MPEG video in real time. This means that there isn't a second compression stage after you capture the video to your computer. It can save a lot of time if you have a large number (say, hundreds of hours) of analog tape. Examples include products from Darim and Optibase. Otherwise, you'll be using some kind of software encoding to convert the video on your computer into an MPEG format. Fortunately, given the speed of most recent desktop computers, this second step is usually faster than real time.
- Capture cards usually come with some kind of video editing software, even if it's only a "lite" version of a more expensive video editor. If you will be doing substantial amounts of editing, effects, and titling, you'll want to check out the various features of the editing packages. For instance, if you will eventually prepare teaching materials or video deliverables to your funders, then you'll want to use some editing features to present a polished product.
- A number of manufacturers (e.g., ATI, Matrox, NVidia, Hauppauge, Leadtek, AVerMedia, Pinnacle) make video display and/or TV tuner cards for PCs that also include the ability to capture analog video. If you're already in the market for a new display or TV Tuner card, this could be an attractive option.
- You should make sure your computer is up to the task. Generally speaking, if you purchased your computer within the last 18-24 months, then you should be okay. Be forewarned, however, that the quality of the video you will be able to capture will be sensitive to your processor speed, amount of RAM, and the type of interface for your capture hardware (e.g., pci card vs. a USB 1 or USB 2 port). In addition, digital video takes up LOTS of hard disk space, anywhere from 1-13 gigabytes per hour and more, depending on the quality of video you desire. And of course, you'll need to verify that your computer operating system (Windows or Mac) is appropriate for the hardware.
- While it is very feasible to get relatively inexpensive hardware to capture analog video onto your computer, if you are going to continue to do video research in the future, we want to make a recommendation here: get a Mini-DV camera with analog inputs. It's clear that just about everyone is moving to the Mini-DV format and it represents the best quality video you can get for the money. In essence, you will be using your camera as a capture device by running the analog audio and video signals into the camera, which will then convert them to the Mini-DV format and send it directly to your computer over an IEEE-1394 or "Firewire" connection in real time. In addition, you will be able to videotape all your future data in this superior format. It costs more to buy a Mini-DV camera than a simple capture device, but the difference is worth it. You can read more about this format below.
Ideally, this is the format you want to be using. It's very high quality, a compact physical format, computers are increasingly designed with this format in mind, and there's a lot of hardware available for it. It's become the standard and prices for DV camcorders continue to drop.
We don't recommend going with one of the DV "pro" camcorder formats such as Sony's DVCAM or Panasonic's DVCPRO. All of the equipment is significantly more expensive and offers a lot of features that you, as a research videographer, probably won't be using. Quality differences between the consumer and pro tape formats themselves are negligible, though the pro equipment can produce better-looking video due to its superior optics and electronics. The Mini-DV format is definitely the better choice for researchers unless there is some compelling reason for using a pro format, such as already having a lot of the equipment on hand.
If you own a recent Mac OS X model, capturing DV video is no problem; you have both the hardware (a Firewire port) and the software (iMovie) to capture DV directly from your camera or DV tape deck. With the introduction of the Mac version of Transana, this should become a popular solution.
If you own a Windows computer, your situation requires a bit more effort. You'll need an IEEE 1394 (Firewire) DV capture card for you PC if it doesn't already have one, and some video capture/edit software. Fortunately, most DV capture cards are pretty inexpensive (often they cost less than $50) and they often come with basic capture/edit software (e.g., Ulead Video Editor), though you may need to upgrade or add a plug-in to get MPEG encoding. For full-featured video editing--including MPEG encoding--on the PC we recommend Vegas Video, formerly owned by Sonic Foundry, but recently purchased by Sony.
After installing the card and software, it's a simple matter of plugging in your camcorder, capturing the video, editing it if you wish, and then compressing it to MPEG video using the software.
If your video is already digitized and compressed, but in a non-MPEG format, that requires a somewhat different approach. What you'll need is an application that can "transcode" your video from its current format to MPEG. Applications like Discreet's "Cleaner XL" do a great job converting from or to just about any format and allow a lot of tweaking of your video, but they're relatively pricey. There are also a number of free or inexpensive utilities on the web, such as FlaskMPEG, TMPGEnc or AVI2MPG (was at http://www.mnsi.net/~jschlic1/, but this seems to be down at the moment).
The video hardware field changes rapidly and requires up-to-date research. Here are some helpful sites to start with:
(If you're looking for the answer to a specific question in a newsgroup, you can search it using Google's wonderful "Groups" interface. Go to Google.com, click on the "Groups" tab, and either enter your search terms or click the "Advanced Groups Search" link to enter your search and limit it to a group such as rec.video.desktop.)
||Highly recommended. Just about every question you can think of has been asked on this group and it always has lots of hardware/software advice.
||More often about complex technical, business, and professional issues in commercial video, but still has a lot of good information from people who are extremely knowledgeable.
More About Video Equipment
For reference purposes, here are three different video equipment setups. These are B&H prices as of 2/9/04
Heavyweight Setup ($4356)
Sony DCR-VX2100 3 CCD Mini DV Camcorder - $2400
Sony VCL-HG0758 0.7x Wide Angle Lens - $270
Sony NP-F750 Extra Battery - $75
Bogen 3445 Carbon Tripod w/ 3433 Video Head - $614
Sennheiser ME66/K6 Shotgun Microphone - $380
Sennheiser MZW-66 Windscreen - $37
Sennheiser MZSCAM Camera Shock Mount - $40
Studio 1 XLR-BP XLR Adapter - $130
Audio-Technica AT83141.5 XLR M/F 1.5 ft Cable - $10
Samson UHF Micro 32 wireless mic (M32/t32/at831) $400
Middleweight Setup ($2143)
Sony DCR-TRV950 3 CCD Mini-DV Camcorder - $1600
Sony VCL-HG0737X 0.7x Wide-Angle Lens - $135
Sony NP-QM71D Extra Battery - $70
Bogen 3011BN Tripod w/ 3126 Fluid Head - $168
Sennheiser MKE 300 Shotgun Microphone - $170
Lightweight Setup ($1313)
Sony DCR-PC105 1 CCD Mini DV Camcorder - $770
Sony VCL-HG0730 0.7 Wide Angle Lens - $135
Sony NP-FM50 Extra Battery - $46
Velbon MAXi 343E Tripod w/ Ballhead - $70
For All Setups
Good Quality Folding Headphones - $50-100
Appropriately-Sized Video Equipment Bag - $50-100
Sufficient Mini-DV Tapes for Taping and Backup - As Needed