Hauppauge250 Hack

[Torrential]

Is there a way to make the Hauppauge 250 capture directly from the preview pin to an AVI container? The video from the preview pin looks perfect but when I capture it to mpeg at a high bitrate (8000) a bunch of noise gets added. Thanks for the help.

[yoda313]

Check out www.shspvr.com They have a ton of info on the hauppauge cards specifically.

[SHS]

The problem with PVR 150/250/500 and even the USB2 is it AVI it not a standard AVI it know as NV12 which is a non stardard YUV format color space.

[vhelp]

I'm confused. I thought the PVR-250 model, was hardware mpeg only..?
( ..is analog capture too ? )

-vhelp 3910

[jagabo]

I'm confused. I thought the PVR-250 model, was hardware mpeg only..?
( ..is analog capture too ? )

Yes, the preview pin is uncompressed NV12 and it's possible to capture from that. Unfortunately, from my experiements I haven't been able to do it reliably. I have been able to capture from the preview pin (I have verified that this has not been compressed to MPEG) with GraphEdt. I route the preview pin (NV12) to the Hauppauge WinTV Color Format Converter filter (YUY2), then to an AVI file writer or the Dump filter (raw byte stream). This works but frames are dropped.

[jagabo]

Is there a way to make the Hauppauge 250 capture directly from the preview pin to an AVI container? The video from the preview pin looks perfect but when I capture it to mpeg at a high bitrate (8000) a bunch of noise gets added. Thanks for the help.

The preview you see in WinTV2000 is deinterlaced by default. But the video that's captured is interlaced. If you view the MPEG file with a player that doesn't deinterace you will see interlace comb artifacts. Burning that MPEG data properly to a DVD will give you a normal picture when you watch it on TV.

I just wanted to make sure you weren't seeing the interlace comb artifacts as "noise", it's perfectly normal when viewing interlaced video on a computer.

[vhelp]

jagabo, honestly, I don't believe this can be true.

From my many experiences with various hardware mpeg capture devices, (but
not to includ dvd recorders) the capture or preview window is the just
that.. of the captured video, or capture and MPEG encoded "output" video.

What got me started in this belief was on account of a prev expereience
with TMPGenc's encoding window. I used to believe it was the AVI that we
were seeing. But, thanks to my keen perception I ran a little test
(which I will ask that you do as well) where, inside TMPGenc, I set the
bitrate very low, like cbr 300, and watched the TMPGenc's encoding window
output the video. It was there, were I noticed pixelations

I also ran this test inside my ADS DVD Xpress box, and I received the same
exact end result.. pixelation. So..

My request to you, if you are curious truth and knowledge, is to please
run this same test. Setup your PVR-250 to a very low bitrate, and then
observe the mpeg output window.

What this test will bring:

** if the video window shows pixelation, then you are actually getting hardware
mpeg video, but from the mpeg chip. This is the most probably intended course.

** but, if the window does not show *any* pixelation, and the video image is
prestine as the source, then what was descrbed earlier has some weight and truth
to it - can be captured as RAW video elsewhere in the chain, through hack or
other means.

But, as I said ealier, this is a hardware mpeg device. And this mention of
a "pin" is misleading. And is leading toward the belief that it is a wire
-separated- from the hardware mpeg chip, and only need to be bypassed in some
way to produce an RAW image. This is what I am having trouble believing.

In any case, the above test should be considered a look at

-vhelp 3912

[davideck]

vhelp - I have tried your experiment with my PVR-250

I do see a difference in the preview screen PQ when changing bitrate.
I also see a difference when I change the capture resolution from 720 to 352 (for higher bitrates).

[vhelp]

davideck,

thank you -- for testing this theory out for me.
-vhelp 3913

[jagabo]

Here's an example of a capture with my PVR-250 set to 720x480, 800 kbps:



Here's the luminace channel from a capture from using GraphEdt from the preview pin (without changing any settings):



WinTV2000 with the PVR-250 can only do one or the other at a time. It displays the uncompressed NV12 data when it's not recording. When it is recording it decompresses the MPEG stream and displays that.