Render Problem?

TalawaMan wrote on 3/20/2004, 12:23 PM

I have a project set up for 720x480 using this template (NTSC DV (720x480, 29.970 fps)) and when I view the output AVI in Windows media player it appears to be half the resolution. Now, the orginal video viewed in media player too appears to be half this resolution as well. I the video was captured from a Cannon ZR25 MC recorded in SP mode and I could find no settings in the capture software to capture at a higher resolution.

My questions:

I would suspect Vegas to render at the higher resolution even though the captured video is lower resolution. Am I mistaken?

The spec for the ZR25 MC says that the CCD has between 290K (effective) and 460K pixels, 720x480 res is about 345K pixels. So I would expect that the output from the camera should be 720x480. Does the mini DV format imply a certin resolution?

Thanks ahead of time,

Jacob

Comments

AZEdit wrote on 3/20/2004, 1:19 PM

DV and DVCAM formats are 5:1 compressed with a video data rate of 25Mbps. The format is 720 x 480 as you expected. In my, and many coworkers opinion, DV (DVCAM) is a better picture than the pld broadcast standard of Beta SP....if the entire project starts and ends in DV. Where DV lacks is that it is 4:1:1 so if you dub Beta SP to DV you will take a chroma hit on the first pass....
"I would suspect Vegas to render at the higher resolution even though the captured video is lower resolution. Am I mistaken?" You can never really improve on a resolution...in other words if you start with VHS the picture can never really get better resolution than the original. That said, with many plugins and color correction you can make it look better...but the mere fact you put something in Vegas does not mean it will render at a higher resolution. You can waist the time and space to render DV as uncompressed but the video will never be a higher resolution than the DV 5:1 compressed picture ... hope that makes sense.

As far as playback in widows media player....did you render your project as "Good" or "Preview" - that will make a difference. Your DV video from your camera should look the same, not worse, when leaving Vegas- unless you have your settings wrong.

"Does the mini DV format imply a certin resolution?" Acyually Mini DV is the same as DVCAM (or an SP setting on your camera) as far as the signal is concerned. The only real difference is the tape itself and in DV mode you can recoed 60 minutes on a Mini DV tape- in SP or DVCAM you can only record 40 minutes.

TalawaMan wrote on 3/20/2004, 2:23 PM

"hope that makes sense."

It does. I do have the render quality set to best. If I right click on a clip in the timeline Vegas reconizes the file as 720x480x24 (BTW, what does the x24 mean, fps). The rendered file is of the same "quality" as the original file, but when a view the file in medial player with a screen resolution of 800x600 and the video set to 100% the image takes aproximatly 1/4 the desktop. The picture looks great, but if I up it to 200% is looks pixelized.

I also agree that if the orginal video is lower resolution then the rendered file will either be pixelized or resampled.

Jacob

rebel44 wrote on 3/20/2004, 6:07 PM

I have GR-DVFU JVC camcorder what it is DV NTSC video format. 520 lines of horizontal will record very good in 640X480, buty when I render in 720X480- extracted single frame pic look little grainy. I assume that your camera it is not 640X480. Most likely 320X240. Will look good on TV, but in DV format (720X480) will pixelate. What I learn- that most digital camcorders are capable 320X240 unless are NTSC format.
520 line are standard for NTSC. About pixels my camera have 680.000 allmost twice what it is yours and still effective most in 640X480.
The horizontal line of resolution it is what make the recording.
I did render all of my vide in 720X480 and look great, just the single frame have less details.

TalawaMan wrote on 3/26/2004, 1:08 AM

Okay, something I discovered tonight that I don't quite understand. My captured video is an AVI format. When I render it to a 720x480 AVI it comes out half the resolution 310x240. But, when I render it to a 720x480 MPEG2 it comes out not only at the right resolution, but with much higher quality than the AVI render. Maybe this is common knowldge but it was a great discover for me.

Anyone have any pointers to sites that have more insitefull information like this?

Chienworks wrote on 3/26/2004, 4:26 AM

By default, Media Player displays DV files at half resolution. In Media Player go to Tools / Performance / Advanced and set the Digital Video setting all the way to the right to 'Large'. Now your rendered files will play in Media Player at full resolution.

Also, in the '720x480x24' the 24 stands for bit depth.

TalawaMan wrote on 3/26/2004, 9:44 AM

Wow, whoda thunk. Thanks.

...So I set up a project with SMTPTE bars and render it in both AVI and MPEG2 (quality best, NTSC DV) and the MPEG2 file looks better that the AVI yet is almost 20x smaller. This is perplexing, should the AVI be better quality?

Jacob