How to deinterlace in capture mode?

[Joni]

I´m trying to capture from an analogue camera, and I want to deinterlace the video in the same process.
The capture should be in 720x576, but the deinterlace filter in Virtual Dub prints "deinterlace 320x240" and it doesn´t work. Why can´t I change the deinterlace filter to work on 720x576 in the capture process?

I don´t want to deinterlace after the capture process, because then I have to choose "full processing mode" to access the filters and the video will be colorspace converted (atleast I think so).

Help me, please

[jggimi]

Analog capture requires realtime processing. So-called "fast" De-interlacing methods typically work by using a single field, rather than a complete frame. These methods therefore effectively cut your resolution in half -- from 576 lines to 288 lines.

When capturing, if you want a "fast" deinterlacer, you can either set your driver to capture with a vertical resolution of 288, or you can use capture software that includes a "fast" deinterlacing filter set (which uses 288 lines and resizes). Either way, your results will have a similar perceived quality, regardless.

I would only recommend a fast deinterlacing method to you if you were capturing where a vertical resolution of 288 is sufficient, such as for VCD. For larger resolutions, slow deinterlacing will provide much better results. Slow deinterlacers examine the pixels, and either blend or interpolate, or both. Therefore they cannot be used realtime.

However, if you use AviSynth scripts rather than Vdub filters, you can use "Fast Recompress" encoding method rather than Full processing. This will allow you to stay in YUY2 colorspace. For more information on AviSynth use with Capturing, see the Capture Guide (http://www.doom9.org/capture/start.html).

[Kika]

@Joni

Produce a small Dummy-Video with the same than the Capture-Size.
Open it in VirtualDub, set the Filters (maybe FieldBob smooth/smooth), don't close it and switch to Capture-Mode.
Now it works. But you will only get a simple Deinterlacing with Blending.

[stickboy]

Originally posted by Joni
I don´t want to deinterlace after the capture process, because then I have to choose "full processing mode" to access the filters and the video will be colorspace converted (atleast I think so).VirtualDub filters operate only in the RGB colorspace. Therefore, if you applied a VirtualDub filter during capture, you still would be performing a YUY2->RGB colorspace conversion, except then you'd be doing that conversion during capture, and then your capture file would be 50% larger.

[ppera2]

Originally posted by Joni
I´m trying to capture from an analogue camera, and I want to deinterlace the video in the same process.
The capture should be in 720x576, but the deinterlace filter in Virtual Dub prints "deinterlace 320x240" and it doesn´t work. Why can´t I change the deinterlace filter to work on 720x576 in the capture process?

I don´t want to deinterlace after the capture process, because then I have to choose "full processing mode" to access the filters and the video will be colorspace converted (atleast I think so).

Help me, please

Why want you direct capture with deinterlace in AVI? What is your codec? Btw. aspect ratio is bad by 720x576...

You will anyway get whether too big file, whether bad quality...

Instead capturing to AVI, you may try to capture to Mpeg2. Win DVR performs deinterlace while capturing. Pinnacle Pctv Vision has choice to deinterlace or not... but works only with their cards. You can get DVD compatible video right with this programs. Space consumption is less than for decent AVI capture.

[olnima]

If You use VirtualVCR You can use the deinterlace-filter from powervcr (it's in the trial-Version) and put it into "Filters" in the "settings"-Menu. It's fast enough for realtime-deinterlacing but I don't know, if the quality is good enough for You. Give it a try.

Olnima

[Darksoul71]

Beside VirtualVCR and the Cyberlink Deinterlacer you can also try
Showshifter (Shareware) and the TV Plugin for myHTPC. Both can use DScaler as realtime deinterlacer. Showshifter gave me nice results.

Of course deinterlace after capture still provides the best results but in some cases realtime deinterlacing makes sense.
Like capturing 512x384 in DivX and deinterlacing on the fly.

You´ll find the TV Plugin here:
http://myhtpc.net/plugins/index.php?showthis=2482

Hope this helps,
-D$

[Owen]

Virtual VCR users can also use the outstanding ffdshow filters during capture.
Or better yet, use the ffvfw codec in your favorite capture app. That will give you all the ffdshow filters built in, plus the best real time Mpeg4 codec going.
For normal video deinterlace this works as good as any other method. (I can’t comment on NTSC 3:2 pulldown performance).

If you are using WDM capture drivers VirtualDub is useless for capture (only half resolution). Use a WDM capture application and never look back.

Hopefully VirtualDub will support WDM capture soon.

Regards,

Owen

[Darksoul71]

@Owen:
Sorry if this is OT:

Or better yet, use the ffvfw codec in your favorite capture app. That will give you all the ffdshow filters built in, plus the best real time Mpeg4 codec going.

Questions: Where can I find ffvfw and how can I use ffdshow inside ffvfw ?
I´ve once downloaded a version of ffvfw that provided the same interface as XVid without any ffdshow filtering options. Also capturing worked only in VDub.

Thanx in advance,
D$

[Owen]

Darksoul71,

Get ffvfw-20030927.exe here:

http://athos.leffe.dnsalias.com/

It has ffdshow functionality built in.

I recomend you use a WDM capture application.

Owen

[Darksoul71]

Owen,

Thanks for answering.
Have a nice XMas !

-D$