YUY2 Hack in PCVCR?

[Prospero]

I have the YUY2 hack, but has anyone got it to work in pcvcr? I have to do the caps I'm doing on timer record, so I realy cant use another program to cap with. I'm recording tv shows while I'm at work and rendering to mpeg4. This would look a whole lot better if I could capture in YUY2 first. Anyone have any suggestions? Thanks for your help
Prospero

[Michel Carleer]

Unfortunately, PC-VCR completely bypasses the capture driver for the selection of formats. It uses it's own dialog boxes which are not affected by the YUY2 patch. It also restores the registry entry to either RGB or MJPEG, so that the registry hack won't work either. Sorry, but I don't think it is possible to capture in YUY2 under PC-VCR.
Michka

[Flying dutchman]

If I'm not mistaken, AVI_IO has a timer setting for capturing.

[Prospero]

Do you know off hand if it will set the channel? I suppose I could leave the pcvcr remote running, I'll look into it. Thanks.
Edit
I downloaded it, and it will do everything that I want. There's only one catch, I'm running an IDE hard drive. I just checked and full res capture in YUY2 requires 19mps. This is just a bit higher than it benchmarks. Is there another codec that is any better than MJPEG for capturing? I render to mpeg4v2 after capture. Thanks again for your help.

[This message has been edited by Prospero (edited 16 April 2000).]

[Driver]

Why don't you encode to MPEG4 in realtime? The big plus about using the YUY2 format during capture is that you can pipe it into a compressor for real-time encoding. No need to keep the actual YUY2 data. In fact, i don't think YUY2 was ever really meant to be captured by itself.
Also, i'm pretty sure that there is a way to prevent PC-VCR from altering the color format. from what i'm noticing on my own system, PC-VCR does not change the color format. i then have the morgan codec set up as dmb1. if it helps i'm using the macrovision free video tools and the latest drivers for the g400 under win98. i can't really elaborate any further because it wasn't something i set out to do but rather just noticed.

[This message has been edited by Driver (edited 16 April 2000).]

[Prospero]

What kind of cpu power do you need to do full res mpeg4 capture realtime? I'm new to a lot of this but wouldn't that require setting up something called a frame server?
I'm capturing 704X480 and rendering to mpeg4v2 later. My system is as follows.
Athlon 700
384meg ram
marvel g400
18 gig wd 7200 rpm system drive
40 gig maxtor 7200 rpm capture drive
Hoontech digital NX soundcard
10/100 Nic

If anyone has anysuggestions or tips, I would love to hear them. I've figured out a lot by browsing forums and doing archive searches, but help is always appreciated.
Thanks.

[Grigory]

Hi,
YUY2 format, being 4:2:2 digitizing format, is used for video capture for a long time. This format only requires very fast hard drive, which was feasible some time ago only for huge RAID arrays. Now this format seems to be useful for everybody.

Mpeg4 uses filtering before compression. The filter is something like blur, thus it is mixing neighbor lines in a video. If you try to capture in full height, then this filtering would mix the fields in video. Even if you have fast enough CPU, this compressor would degrade the picture.
With SIF size, MPEG4 is only useful if you capture a movie that you don't want to edit. Otherwize you'll get a lot of compression artefacts after rendering effects.

Funny enough, some time ago the cheap video tuner cards like those based on BT848 chipset were named unsuitable for video editing just because they did not have hardware MJPEG compressor on board. Now, with fast hard drives and CPU's, those cards (40$ or less) have got new life. You can easily capture in 4:2:2 YUY2, 4:2:0 (several types), or 4:1:1 (best for analog tapes, because of correct luma-to-chroma resolution ratio) formats, and use several types of software compression.
Even Canopus DV Raptor analog capture kit (freeware addition to DV Raptor) can capture with 4:2:2 color space allows realtime MJPEG or mpeg4 compression.
Don't you think that zoran MJPEG chip is coming to the end of life ?

Grigory

[Flying dutchman]

You could try either capturing YUY2 at 1/4 size, such as 352x288 or 352x240 (5.5 mb/sec), or full-frame MJPEG which requires subsequent steps such as de-interlacing and scaling.

Capturing 1/4 size YUY2 is the fastest process. You can use virtualdub to join all these segments into one (mpeg-4 compressed) AVI film which gives a lot better quality than capturing into mpeg4 directly; the codec simply has more time to do its job properly and can create higher bitrates. Real-time coding seldom gives a bitrate higher than 1.5 mbps. These files are excellent source material to convert into VCD format, too!