DV capture questions...Please reply...

[vasudev71]

Hi,

For Windows XP firewire capture from a NTSC DV camcorder, do I need to change the video resolution (e.g) from 1024x768 to whatever maximum my monitor supports? This question also holds good for editing/rendering and all the way up to DVD authoring.

Also, when does a DV codec gets involved in the whole process?
I heard that there is no codec involved during firewire capture. If this is true, when does a DV codec get involved? For example, if I render straight out to MPEG-2 for DVD from within Vegas/Premiere timeline, I guess the MPEG-2 codec will get involved here. If thats the case, when is DV codec involved?

Would appreciate replies.

- VSS988

[jkwarras]

Hi,

1) DV firewire capture has standard settings that normally you can't change. Uusally there's 720x576 resolution for PAL DV and quite similar applies to NTSC (i don't remember exactly values). So you can't change resolution capture (someone correct me if I'm wrong). May be special cams produce such resolution but i doubt about it at a consumer DV range product. moreover, trying directshow capture (i.e. via MediaPlayerClassic) doesn't allow you to change this values.

2) The Dv codec isn't used in capture via firewire. The firewire just connect your cam to your PC and transfer the data exactly, doesn't touch it or convert it, blabla. Dv codec applies when editing and you're changing something in your video, for ex. transitions, effects, denoising, fades, etc... the computer needs to rewrite this new data, and use the DV codec. When you playback your DV footage, DV codec is used to decode it. If you want to convert your DV to DVD, then the DV codec is also used to decode the footage.

Regards

[vasudev71]

Hi,

Thanks for your reply.

I think you got it wrong. I'm not asking about the DV resolution. I was asking about PC video resolution (1024x768) to something maximum my PC monitor supports.

Also, I putting up my question again with respect to DV codec.
I still don't understand the previous reply.
Anybody explain me in detail?


Arky...Can you reply?

- VSS988

[theReal]

Never upsize a video from its original resolution! To upsize DV video from its native 720x576 (PAL) or 720x480 (ntsc) to something like 1024x768 wouldn't be a good idea. First you are loosing quality in the upsizing process, second you're getting more data you'll have to save.

Every video should be kept in its original resolution to preserve full quality. On playback, software players are capable of upsizing on the fly so you can watch the video full screen.

btw. the DV codec only supports two resolutions: 720x576 for PAL and 720x576 for NTSC

[jkwarras]

Originally posted by vasudev71
Hi,

Thanks for your reply.

I think you got it wrong. I'm not asking about the DV resolution. I was asking about PC video resolution (1024x768) to something maximum my PC monitor supports.

I think it doesnt' change very much. It's more a personal preference matter. If you set your monitor resolution to max. you'll have more screen space to work. But in a pure visual aspect i don't think chanigng from 800x600 to 1024x768 will change very much. USe your max. desktop resolution settings.

Also, I putting up my question again with respect to DV codec.
I still don't understand the previous reply.
Anybody explain me in detail?

The DV codec will be used if you're making transitions, aplying effects, changing colours, etc.. to your video. The computer need to ENCODE (recompress) it in order to write the new data (fades, transitions, etc..). Thats it. In other usages the DV codec will only DECODE the footage.


[/B]

[bb]

Originally posted by theReal
btw. the DV codec only supports two resolutions: 720x576 for PAL and 720x576 for NTSC
Must have been a typo: NTSC DV resolution is 720x480.

bb

[alba_zeroX]

ntsc 720 x 525 there are 525 lines just the top and bottom are cut off to form a 480. making 720 x 480 to 1024 x 768 is a little bad, because 720 is a rectangle and 1024 is a square, upsizing is bad too, quality and size go to a bad level.

[theReal]

ntsc 720 x 525 there are 525 lines just the top and bottom are cut off to form a 480. making 720 x 480 to 1024 x 768 is a little bad, because 720 is a rectangle and 1024 is a square, upsizing is bad too, quality and size go to a bad level.

Actually, it was a typo, I wanted to write 720x480 and I meant the visible lines. Of course you're right and there are more lines which carry the data for sync, videotext and other stuff. The full PAL picture also has more lines of course - AFAIK it's 625 lines.

[FredThompson]

Why do you guys think the question has anything to do with resizing the DV original? I see no indication of that. I see someone who is unfamiliar with computer editing of video thinking their monitor resolution has to match the DV resolution, similar to using a TV to edit between VCRs.

Your display should be at least 800x600 because you need room for the DV preview. Video pixels are not square, computer pixels are. No matter what, you won't be seeing a perfect representation of the DV image.

Also, learn about 4:1:1 and what that means. You'll probably want to do some cleanup if you plan to compress to an MPEG format. 411Helper for VirtualDub and Reinterpolate411 for AviSynth are designed to do this. You can find my DV->CVD/SVCD/DVD script for DVD2SVCD in the DV area.

[communist]

Originally posted by theReal
btw. the DV codec only supports two resolutions: 720x576 for PAL and 720x576 for NTSC
Doesnt it also support : 360x288 and 180x144 for PAL?!

[FredThompson]

no

DV is a set frame size and a set data packet size per frame.

[theReal]

Why do you guys think the question has anything to do with resizing the DV original? I see no indication of that. I see someone who is unfamiliar with computer editing of video thinking their monitor resolution has to match the DV resolution, similar to using a TV to edit between VCRs.

Your display should be at least 800x600 because you need room for the DV preview. Video pixels are not square, computer pixels are. No matter what, you won't be seeing a perfect representation of the DV image.

OK, but the question was kind of odd (no offense - but you see that almost everybody got it wrong...)

A higher resolution will result in more working space on your monitor, so - of course it's good to have a higher resolution!

I'm working with 1280x1024 on a 21" monitor and honestly it's not perfect for editing. The best setup for editing is two monitors (at least 19") with a 1280x2048 resolution plus a seperate tv monitor for preview.