Welcome to my short meta-FAQ on getting started with desktop video
(draft v0.2, 10/11/04)
Why read this?
If you ask me how to watch TV, archive your old VHS or Hi-8 tapes, or record shows onto your PC, I am going to refer you here. I write better than I speak, and the picture will be much more complete if I can stand on the shoulders of my peers.
Why not read this?
If you want one-click recording or the ability to pause live TV, you want something covered by the
PvrFAQ. If getting video into a commercial editing program quickly is more important than cost, or you own a digital camcorder, consider a
DvBridge. If your home videos are on film (e.g. 8mm) or you need large-scale duplication, the necessary equipment will be beyond the scope of this document; I suggest contacting a
professional media company∞ (shameless link) in your local area. Durham:
Avid Video∞ is next to Duke East Campus. Chapel Hill:
Cirque Productions∞ is on Brookside Dr.
What do I need to buy?
The TV/video capture cards sold by
Intrex∞ are both based on a longtime industry-standard chipset from Brooktree (now owned by
Conexant∞). The BT878 chip can capture any analog NTSC source to your PCI-based machine, sampling it as 8-bit digital video at a variety of resolutions up to 720x480 4:2:2 (YUY2). Don't worry about the details until you read some of the guides below. Suffice to say it's capable of very high quality; most of the TV shows, VHS & Laserdisc rips, etc. you see floating around the Net were captured on hardware that cost $30 four years ago. I'm compiling a
VidCapSamples page to showcase what raw, unprocessed signals from around the world look like when fed into various cards; eventually I'll have time to write moderately comprehensive reviews and comparisons, so check the
current discussion thread∞ every now & then.
The
ATI and Avermedia cards∞ both take composite video (e.g. from a VCR, camcorder, cable box, etc.) and can tune channels directly from analog cable or OTA (over-the-air antenna) TV. For another $30 the Avermedia adds support for S-Video (
Hi8 cameras and some cable boxes; VCRs will probably not benefit), FM radio tuning, stereo sound on the video tuner, and a small remote control. In each case you must run a mini 1/8" cable from your source (i.e. the BT's line-out if using the coax tuner) directly to your soundcard's input, or use an internal patch cable.
Choose the Dazzle lineup at your own peril.
Software!
For simply watching TV in a window or fullscreen, nothing beats
DScaler∞. Excellent direct control of Brooktree chips (as well as a few 10-bit successors like the Conexant CX2388x), keyboard / remote navigation, and most stunningly, put your CPU to work processing the image with better filters than you'd find in almost any high-end hardware line doubler. If you have the horsepower, I like turning on
MoComp2, Temporal Comb, and Adaptive Noise after calibrating colors and contrast.
The quality of recording ("capping") software distributed with these cards varies widely, but excellent universal drivers for this family of cards are maintained by the
BTWinCap project∞. These conform to the Windows Driver Model (WDM) that most recent capture applications talk to.*
VirtualVCR∞ is the free program I recommend most -- very clean and easy while supporting the card's most important features and any video compressor you have installed.
VVCRS2∞ adds basic scheduling ability.
(Please do not let me give the impression that these simple tools (or any others) can replace a real PVR like
Tivo∞ or
ReplayTV∞. See
PvrFAQ.)
If your primary interest is in
editing video -- say, home movies -- then you probably want a commercial product in the vein of
Sony Vegas∞ (my favorite) or
Adobe Premiere∞ or
Final Cut∞ (Mac only). They are typically not as strong at actually capturing analog, hence work best with a
DvBridge, but should do fine so long as you read the next FAQ on codecs. If you're on a budget, each company above also distributes "basic" or "home" versions of their programs for under $100; other options are
Ulead∞,
Pinnacle∞, or
Avid∞ (DV only). Windows XP users can try Microsoft's free Movie Maker as well by grabbing the latest version from
Windows Update∞.
How much disk space we talking about?
Lots. Cards like these with no onboard compression will be sending around 20MB of data to your CPU every second! If you write the full 720x480 resolution straight to disk, you're going to eat around 60GB per hour. The solution is to use a
codec (compressor/decompressor) to shrink sizes to something more manageable while providing a standard way for your software to interface with video data.
Lossy
- MJPEG (motion jpeg) and its variants are what most people use since they can get standard-res video down to 10:1 (6GB/hr) or better without quality hits visible to the naked eye nor compromising your ability to make edits. (MPEG flavors have tighter compression, of course, but since they don't store the full information for each individual frame, editing becomes a painful and lossy process.) There is a decent MJPEG codec included in ffdshow∞; many commercial vendors also sell MJPEG codecs, such as Pegasus∞, Morgan∞, and LEAD∞. Microsoft themselves have a couple of similar codecs (decompress/read-only) designed for DV. Anytime you see DV mentioned, the technology is equivalent to MJPEG for all practical purposes, just with its own file format and standardized settings (consumer DV is 5:1 with 4:1:0 chroma subsampling; DV50 uses 4:2:2). Thus, professonal capture-hardware companies like Canopus∞ and Matrox∞ write or license DV codecs to package with their products, as do digital camera & camcorder companies from Canon∞ to Sony∞; luckily, most of these devices can write files readable by the free codecs and vice versa.
Lossless (i.e., you get the exact same video back when you uncompress, just like a Zip file -- even if you can't see the quality improvement vs. lossy, your final/distribution MPEG encoder's compressibility tests probably can!):
- HuffYUV∞ is time-tested and fast (30fps on a Celeron 450). Expect compression rates between 3:1 and 1.8:1, or 20-30GB/hr depending on how much of the color gamut is used.
- ffdshow∞ has a lossless compressor that's capable of slightly smaller files but takes more CPU.
- Several proprietary codecs exist: I think Pegasus has one based on lossless JPEG, recent versions of Sorenson Squeeze supposedly have something lossless, Apple has codecs designed for animation...
Guides
I won't pretend to summarize the information needed to set up, cap, and postprocess videos at an advanced level. When making archives of shows or home movies that are important to you, I think it's best to do it
once the right way. The steps leading up to your master DVD aren't always obvious.
Offsite Links (budget some time...):
- Ars Technica's guides to capture∞ and postprocessing∞ -- a few parts could be updated, but Matt and I worked hard to make sure the underlying concepts you learn won't ever go out of date. Check back "soon" for the 3rd installment (compression, mastering, and burning).
- Doom9 capture guide∞ -- I'm not terribly active with Doom9 outside AviSynth Development∞, but I trust the gurus there to provide the most comprehensive information available. Download the CHM file to ensure you have the latest copy.
- Luke's Video guide∞ -- good overall intro, not updated since 2002 (lukesvideo.com appears to have been taken over)
- Lurker's Guide to Video∞ -- another conceptual intro, geared toward SGI machines / graphics work, but with solid explanations of basic video principles
Reference information (thanks to Anachrotron for the links):
Other articles on this site
This is the home of my
CollectedWritings, after all...in theory. And so, here lies the temporary home of random vidcap-related info I deem worth saving:
Putting it on DVD
to be continued if there's interest...for now a quick list of links:
- Doom9: DVD encoding∞, authoring∞
- Top two encoders: CinemaCraft∞ (~$50) and Tsunami∞ (free -- beware the payware imposters at tmpegenc.com!)
- My pick for the best deal on authoring software -- DVD-Lab∞ ($99) -- should fill the needs of just about anyone who is not a full-time professional but wants more than Nero offers
Where to ask questions?
Ars Technica A/V forum∞ -- a small but dedicated & friendly group of video enthusiasts hangs out here
http://forums.doom9.org/∞ -- largest English-language forum on the web for desktop video
http://virtualdub.everwicked.com/∞ -- general desktop video forum with a nice analog-capture contingent
http://www.tv-cards.com/∞ -- lots of hardware reviews and a knowledgeable forum
I'm looking for a link to...?
The
AV links section∞ of Donald Graft's website (maintained by Fred Thompson, last update December 2003) probably has it.
.
.
.
*Note: if you need old Video for Windows (VFW) drivers for use with capture software like
VirtualDub∞, you will have to use the ones provided by the manufacturer -- under
Win98/ME you're probably fine, but the only manufacturer whose VFW drivers are known to function under
Win2K/XP is
Hauppauge∞. Your mileage my vary.
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IntrexFAQ
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