FireWire: The Wild Card
This year’s wild card is FireWire. With FireWire cards now priced at $49 and digital converter boxes hitting the market for a mere $300, is an analog capture card really the way to go for those of us not ready to give up our analog cameras? Is it time to switch to a digital video capture solution?
Check out our scorecard below to find out how these two approaches compared.
What we tested:
We compared a Pinnacle analog capture card we had against an ADS Technologies PYRO Digital Video FireWire card ($79) and Canopus ADVC-100 analog/digital bridge ($299) combination. The Pinnacle capture card, which cost under $150 new, uses a Zoran processor to compress the incoming video into Motion JPEG (M-JPEG), a popular format. We put it and the FireWire/bridge combination into a 500MHz PIII, 256MB machine partitioned for Windows 98, Windows 2000 and Windows XP Professional operating systems. We then fired up our trusty but dusty Sony Hi8 camcorder and started keeping score.
Half-point goes to DV/FireWire/bridge for low transfer rate
When using the analog card at full tilt (640x480, 30fps and minimum compression), we got a transfer rate of about 6MB/s, which completely swamped our older SCSI Ultra Wide drives but was acceptable to the newer, inexpensive ATA133 IDE drives in the same machine. The SCSI drives dropped frames and couldn’t keep up with the high transfer rate. By contrast, the DV/FireWire link transferred at 3.5MB/s. Even the old-timer SCSI drives were ok with this transfer rate, which was good since there was very little we could do to change the DV encoding.
In the final analysis, the drive issue is moot because even the cheapo IDE drives, which you can buy all day long for less than $200, will write sequentially at better than 15MB/s. That’s more than enough needed for analog or DV. Therefore, we gave the DV/FireWire camp only a half point for transfer rate. (For the remainder of this review, we used the IDE drive.)
One point goes to DV/FireWire/bridge for archiving content
We have had many analog capture cards over the years, and it always seems that one M-JPEG card/driver won’t decode the video from another M-JPEG card, making it a bit risky to store video in any one card’s native format. Our experience is it’s difficult to transport files in the card’s native format from one machine to another, unless both have the same capture card. The only safe storage is to re-compress video with a commonly available software codec, so we can always get at it.
In the other camp, FireWire is simply a transport mechanism that has no bearing on already captured videos. And, DV is a standard compression that’s likely to be supported by many different operating systems and for many years to come. This gives us the freedom to transport files between PCs using different hardware. It also gives us the ability to change existing hardware without fear of losing native video archives.
Half-point goes to analog capture for resolution sizing
The analog card allows several different resolutions, 640x480, 320x240, et al, and can also apply cropping on the fly. You can capture video directly at 320x240 if need be; no resizing required. Other adjustments include the frame rate, video input selection, brightness, contrast, saturation, hue and sharpness.
The DV/FireWire/bridge allows virtually none of the above. The resolution is fixed at 720x480 and there are no video adjustments. If you want to capture video directly at 320x240, you’re out of luck. You’ll need to re-size and de-interlace before encoding, another inconvenience that you can eliminate by using an analog capture card.
It might appear at first that being stuck at 720x480 in the DV format is a bad thing, requiring resizing and re-sampling and therefore adding another step to the capture process. But, in truth, most video we capture using the analog card is stored in a format other than what’s available from our capture card and requires an additional step anyway. Which is why we only gave analog a half point on this one.
Half point goes to DV/FireWire/bridge for audio
The analog capture card requires a separate capture card for audio, so it got no points from us for audio. In the DV/FireWire/bridge camp, audio is handled by the bridge and can be set to 32kHz or 48kHz sample rate. The audio is simply plugged into the bridge along with the video. The audio played back fine after capture but because the DV/FireWire/bridge offered no way to preview the audio while recording, it forfeited a half point.
One point goes to DV/FireWire/bridge for easy installation
The Pinnacle analog card has all the usual driver concerns. When we bought it, it came with the drivers for Windows 98. In order to get the card to work on new Windows XP, we’d have to get new drivers for it, which aren’t currently available. We are at the mercy of the card manufacturer, who may or may not have driver support for new operating systems.
Not so the DV/FireWire/bridge combination. DV and FireWire are universal standards. We aren’t beholden to any one manufacturer for OS support. If we purchased next year’s whizbang PC, we’re relatively certain the DV and FireWire will work on it. In fact, next year’s PC is likely to have FireWire built-in.
We installed the PYRO Digital Video FireWire card into the 500MHz PIII machine running a recently installed Windows XP Professional operating system. We also tried it on a Window 2000 partition in the same machine, as well as a Windows 98 partition, again in the same machine. To our delight, the installation was anti-climatic for Windows 2000 and XP. On the Windows 98 partition, it required a driver that was supplied on the CD-ROM that came with the FireWire card. XP did not even ask for drivers; the card just simply worked. Then, we plugged the FireWire hose into a Canopus ADVC-100 analog to digital bridge and switched on the unit’s power. It, too, didn’t require drivers. Instantly, XP woke up and asked us if we would like to use Microsoft Movie Maker to capture the video. Which brings us to our next point.
A bonus point goes to DV/FireWire/bridge for good XP relations
We have several good editing systems from Adobe, and ULEAD Media Editor available, but we decided to try Windows’ Movie Maker editor, as the friendly dialog box in XP suggested. As we started clicking through the options, we noticed that Movie Maker can produce streamable files in the real timeline while capturing the video through the FireWire link. Wow. One-step capture and stream. Windows XP will capture in native DV or to several streamable formats. That’s an unexpected bonus point in DV/FireWire’s favor.
Quality of picture a wash
Quality of picture turned out to be a wash. Comparing the same video frame side by side from each capture card, we didn’t see any color bleeds, problems with resolution or the effects of noise showing up on the video. The only exception was that the analog capture had a little less contrast and brightness than the capture from the DV/FireWire/bridge. But since the analog capture card provided the means for adjusting contrast and brightness, this too, was a non-issue.
Bottom Line: With four points to analog’s half-point, DV/FireWire with an analog converter box wins hands down in our opinion.
Analog Capture Card
Pro:* Lots of tweaks, different resolutions, picture quality adjustments, etc.
Con:* Hardware dependant (not all M-JEPGs are created equal)
* Needs higher MB/s for max resolution
* Needs more storage for source
* Proprietary drivers, migration path not assured
* Requires separate audio card
DV/FireWire with analog-digital bridge
Pro:
* Hardware independent (all FireWire / DV created equal)
* No or little OS / Driver hassle
* Needs less MB/s for max resolution
* Needs less storage for source
Con:
* Cannot preview the audio through FireWire
* Not tweakable. Resolution fixed at 720x480
Deep Analysis:
We used the Data Rate Analysis feature in the ULEAD Media Editor 6.0 to examine the files created by both the analog card and the FireWire/analog bridge solution. The results, below, speak for themselves.
Above: As shown above, 6MB/s was the average data rate we recorded for the analog capture card. The average frame size was 204.33KB, (the largest frame size, 309KB, was an abnormality at the beginning of the clip). We’d need more storage space on our hard drive to archive 204KB per frame for video captured with this card than with the DV approach.
Above: The transfer rate of the DV FireWire bridge remained consistent at 3.5MB/s, requiring only 117.19KB of disk space for each video frame, about 43 percent less than if we were capturing with the analog card.