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Posted by
Thomas
McGuire on August 27, 2002
Manufacturer:
Sigma Designs Product:
REALmagic X-Card Search
for the lowest
X-Card prices.
Xcard supports ISO-compliant MPEG-4 DivX
files & uses DirectShow to play them. There are several
exceptions to this - DivX 3.x encoded files aren’t
supported, only 4.02 + encoded files are. GMC (Global
Motion Compensation) & QPEL (Quarter
Pixel) encoded files aren’t supported either & movies
encoded with B-frames had jerky playback, the latest 1.2
Drivers however improve playback smoothness with B-frames
however.
The latest drivers from Sigma Designs
come with AviCheck, a utility which allows you to
check a DivX encoded file to determine it’s compatibility
with the Xcard, e.g. Checking the
Warcraft III: Reign Of Chaos trailer resulted in the
following:
Should the file be encoded with DivX 3.x
you’ll receive the following;
As a result these files cannot be played
with the Xcard, currently at least. Do’h. In addition to
testing playback compatibility it also displays a
statistical listing about the file properties itself.
Future Drivers will seemingly fix much of
these issues, with software decoded DivX 3 being
allowed to use the Xcard’s output. No word on GMC/QPEL
though. The just released 1.2 Drivers however attempt to
play regular AVI files as well (Not present in the 1.1 or
1.0 release however), which results in no playback at all as
these are unsupported. This can be resolved thankfully by
unregistering the new rmavi.ax filter (Thanks Nagui).
Enough on what doesn’t work though, how
about when it does. Not being too keen on DivX
myself I downloaded some at the
DivX Showcase, that being the Kermit’s Swamp Years &
Farscape trailers.
Image quality was good, particularly
noticeable when it comes to TV output compared against other
Graphics cards, though fullscreen on the Monitor also was
great, with improvements being essentially the same as when
it came to DVD playback, i.e. less pixelated, reduced
scaling & other artefacts. Frame rate was, as you could
expect, consistent & smooth. Similarly TV output was far
better than that available on my Graphics card & even with
fairly low resolution DivX the results were impressive.
Audio wise files sounded ok, though
(again) in this area Xcard has been receiving Driver updates
to resolve certain issues, e.g. support for low Bitrate MP3
& resolved issues with files with AC-3 audio. Variable
Bitrate audio isn’t supported either so as to resolve
synchronisation problems.
The main conclusion
as regards DivX support though is that you’ll still want to
have the
latest DivX codec installed given the Xcard’s
compatibility limitations, though for those that it does
work with, it works very well indeed. As I’ve asked
for, Sigma Designs will hopefully be posting a guide to
encoding DivX for the Xcard soon, though with the release of
their MPEG-4 encoder this may not be so necessary now.
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