Returning to video - HD questions

ducnbyu wrote on 12/30/2007, 8:37 PM
Hi,

I have been away from video editting for a while. Have VMS6.0a Platinum. I received an HD camera (Canon HV20). I recorded in HD widescreen 1920x1080 24p. It seems that 6.0 does not do HD wide. Forces me into 1440x1080. Any way to get 6.0 to do 1920x1080? I'm considering upgrading to VMS8.0 does it capture HD wide 1920x1080? I didn't see any literature mentioning 1920x1080, it just says HDV.

Also I read that HD playback performance is much better in 8.0. Anyone have info on how HD playback might be with 2.4Ghz and 1GB ram in 8.0?

Also in my 6.0 manual it recommends editting with intermediate video down scaling to DV then replacing with the HD version for rendering. Then I read a recent document (sorry don't recall where I found it) saying the same thing. The recentness of the document implies to me that the same process might be required for 8.0 as well, is that the case.? I'm hoping that's an incorrect judgement.

Next question is perhaps general not limited to VMS. The captured video seems to be MPEG-2. How much video quality, if any, did I lose in that transaction as compared to direct playback from camera to HDTV. Is the video stored on tape as MPEG-2? Therefore no loss?

Thanks,
Rye

Comments

Eugenia wrote on 12/31/2007, 12:07 AM
the hv20 is 1440x1080, your vms recognises it correctly. to get a real 1920x1080 image out of the hv20 you must record through hdmi, the tape only does 1440. upgrade to vms8p, and also make sure you remove pulldown becase hv20's 24p is not true 24p imo. go on my blog to search about the pulldown methods, sorry cant copy it here as i reply via a cellphone.

the hdv compression quality at 1440 is not bad btw , barely noticeable compared to hdmi 1920.
ducnbyu wrote on 12/31/2007, 12:24 PM
Thanks for the info Eugenia. When I capture, the frame is squished to 4:3 which 1440x1080 is 1920x1080 is 16:9 which is the layout of the camera: viewfinder, lcd. So if the image is squished in VMS I don't think its recognized correctly. I will read up on this more though.

I'm not sure what you mean by "record" through hdmi, I record through the lens. Do you mean "capture"? I have firewire on this computer. As I said I have been out of video for a while. Are there hdmi capture cards now? Or is it just a cable from hdmi on the camera to firewire card?

which article on your blog is about pull downs... you have a lot of info to search through. I'm rusty on this so I'm not sure what this is refering to.

Thanks again,
Rye
Chienworks wrote on 12/31/2007, 1:36 PM
Oddly enough, 1440x1080 is not 4:3, it is 16:9. What's happening is that the pixels are wider than they are tall, 1.33333 times, in fact. So if you multiply 1440 x 1.33333 you get the 1920 width that you're expecting to see.

Now, if you were to look at that video on a display that shows square (1x1) pixels then the image will look squished narrow and tall. Right-mouse-button click in the preview image in VidCap. If "display square pixels" is checked try turning it off.
4eyes wrote on 12/31/2007, 2:05 PM
ducnbyu,
In VMS 8 Platinum, where you put your hdv files into the project (the project media bin), right-click on the video and select properties. It should say 16:9 (PAR 1.3333), 1440x1080i Upper_Field First, 25MBS, Mpeg audio @384kbs stereo.
If the preview is wrong check your project settings, your project settings should match the same as your source video. Choose BEST as the quality setting.
You can also right click in the preview window choose a few different methods of how the video is previewed.

There are some HDMI add-on cards for the computer you can add to your system to capture raw uncompressed video directly from the HDMI port of the camcorder. File sizes are huge, I believe you need to setup a RAID array with large fast drives. I would look into all that's involved before considering capturing via raw hdmi.

I guess in a few years they will have devices similar to dvd recorders that will be able to capture HighDefinition direct to disk/drives from firewire/hdmi/component ports.
Eugenia wrote on 12/31/2007, 6:22 PM
http://eugenia.gnomefiles.org/2007/07/13/canon-hv20-24p-pulldown/
ducnbyu wrote on 12/31/2007, 8:31 PM
Thanks for all your comments this clears up my understanding immensely. I was under the impression that PAR 1.33333 was the result of 1440/1080, but now I see that PAR refers to the shape of the pixel. I now notice the the camera manual only mentions 1920 in the "Still Image Capturing" section.

I will reconsider my desire for 24p after upgrading to 8.0. I did also notice scene detection conspicuously missing. Intended to search for the setting, but first ran across the comment that the upgrade to 8.0 is worth it if only for scene detection in the blog (thanks for the direct link).

Thanks again for all your comments and updates on the current state of affairs.
Rye