MPEG Encoder
-
Cirrus Logic CS92210
Video Decoder - Philips SAA7114
Video Encoder -
Conexant BT860
Video Input
-
Composite in / S-Video in
Audio
Bitrate - 128, 224, 384Kb/s -
Sampling Frequency -44.1Khz 48Khz
Line Input Output- 3.5mm Jacks
Encoding File Format
Separate Audio Video Files (*.mpv *.mpa) -
A/V Multiplexed MPEG file (*.mpg)
Click Photo to enlarge 768 x
488 120Kb
The PV256 is capable of
capturing Video ( NTSC - PAL ) and Audio in Multiplexed Mpg file
or separate Audio and Video files in Mpeg1 or Mpeg2 with video
data rates from 1000-1150Kbps Mpeg1, 1000 - 10Mbps mpeg2, Audio
at 128, 224,384Kbps at 44.1, 48Khz and has templates for VCD,
SVCD and DVD modes. The application interface is skinable
allowing the user to create their own skins. Included with the
application software is the SDK for software programmers to
develop their own application and tune the card to their own
specifications.
The biggest problem that has plagued
Video Capture cards for some time is the ability to keep the
audio in sync with the video, especially over long periods of
time. These audio - video sync problems occur because although
the video is compressed in hardware on the capture card, the
audio is compressed using software, and it is up to the CPU and
the computer to keep up with the video data transfer.
The PV256 uses software by
Qdesign to compress the audio on the fly. I tested the PV256
on a 500Mhz and 800Mhz Intel Pentium III and as hard as I could
try I could not get any sync problems. Of course that's not to
say that under certain circumstances it might be possible to
produce the sync problems. The PV256 won't suit every
machine out there. It is unlikely to will work with motherboards
that have video, sound or both on board. Also some older VIA
chipsets will cause untold problems. If you own an Intel or a
recent VIA chipset motherboard with a decent sound and video
card you've got the best chances of the PV256
working. These problems are all related to the Direct Show
application that the PV256 uses. If the video card or
sound card is not fully compliant with the Direct Show
requirements then problems will occur.
Most video capture cards on the
market at the moment can capture Mpeg2 files at very similar
qualities but when it comes to Mpeg1 that's a different story.
Capturing at very low data rates and achieving good quality is
up to the amount and type of filtering applied before the Mpeg
encoder. Different capture cards use different techniques and so
the capture quality varies considerably. For those of you that
have a product that uses the Winbond W99200 encoder (
developed by Zapex and Winbond ) will know how excellent the
Mpeg1 capture quality looks. Making the encoded file look good
is all about optimizing the video filters for the application
being used. The Mpeg1 capture quality of the PV256 is
also very good, almost as good as the W99200. In
qualifying the comparison the W99200 capture always looks
super clean but can suffer from blockiness in moving scenes
where as the PV256 looks less filtered but deals with
moving scenes much better. The PV256 like all other
CS92210 based capture cards uses Parameter files ( *.par )
to load the capture settings to the hardware. These can be
modified to produce different picture qualities. A Parameter
Editor application is available ( check out the PV256 forum ) to
allow easy modification of these settings. With some tweaking of
the parameter files, the PV256 can produce excellent SVCD
VBR captures and the half D1 settings are excellent.
In the right environment the
PV256 achieves very good Mpeg1/2 Video captures and is
excellent value for money.
For another review check out Steve
Kittelsens Page at
http://steve.kittelsen.com/pv256c/
PV256 Tips n Tweaks
VCD captures are not fully
compliant, this may cause some editing programs to not accept
the file.
A simple fix is to capture separate
video and audio files and multiplex them together with another
program.
DVD captures can also cause a few
problems with certain DVD authoring programs.
To get the best performance out of
the PV256, use the following tips.
1) Try to have the PV256 on an IRQ
that is not shared
2) Allocate 64K of DMA buffer.
3) Make sure you have DX8 or later
installed
4) Try and use a fast hard drive or
at least have an ATA100 IDE interface.
5) Don't use a cheap and nasty video
card. Buy something decent
6) Make sure the Video Card has the
latest drivers.
Not all motherboards are born equal.
Try not to buy a motherboard with everything built in, the price
may be attractive but there is a good chance you'll have
problems
