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Is Vegas reliable in importing 23.976fps footage?
I’ve been working on a video with Vegas 6.0b. Project settings are 640×480, 23.976fps. My source footage consists of 23.976fps AVI files rendered with After Effects 6.5 Pro.
After importing one of these rendered files I noticed that the movement was slightly jerky. It turned out that the frames weren’t the same I was seeing in After Effects. The length of the clip was correct though. I then re-rendered the AE composition to a PNG sequence and imported that to Vegas. Now everything was in sync again.
The problem is that in addition to the AE rendered files I’m using huge 23.976fps AVI clips in my project. There is no way I can render these to image sequences to be able to edit frame accurately in Vegas. Should I stop editing in 23.976fps altogether? Are other timebases (e.g. 24fps) more reliable?
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13 Replies
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The problem is because of AE and how it writes AVI files. You will have to use image sequences from AE because Adobe chooses to round off the 23.976 at only 3 decimal places. (It actually goes many more decimal places than 3 and Vegas uses the more accurate math).
You might also consider 655×480 using square pixels as Vegas actually likes this better than 640×480.
Are these all computer generated? What’s your source and also what is your final delivery or destination?
td
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I’m using animation from DVD, inverse telecined and converted to AVI. It’s a training project/parody where I do a lot of modification to the original in After Effects and arrange the clips in Vegas. It’s meant for computer viewing only, so the final version will be a 640×480 @ 23.976fps AVI.
The problem doesn’t seem to be only with AE. I did a test with a 23.976fps AVI I had lying around by importing it both as video and as an image sequence. Their length on timeline was the same, but some of the frames in the video version had shifted. I also noticed jerky motion in some places that was caused by a frame being “freezed” for a frame or two. The image sequence looked just fine.
Can you elaborate on why you consider 655×480 better than 640×480?
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You will find that most others do not properly handle the 23.976xxxxxxx frame rate, and thus you will see just what you have described, so you will need to use image sequences in Vegas to avoid this issue.
Native square pixeled video in Vegas is 655×480 and this can easily be converted to 720×480 (Vegas handles aspect ratios very well).
td
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Tim ~
Would you then suggest that for PAL one would look at 655 x 576?
Chris Young
Sydney -
[Chris Young] “Would you then suggest that for PAL one would look at 655 x 576?”
For Pal, use 786×576.
td
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Check that isn’t 768×576 which is a very popular native square pixel size for PAL.
Maybe a typo by Tim but it is rare you’ll catch him out on detail – so don’t take my word for it. -
Tim ~
As Richard suggests (thanks), is that meant to be 768 x 576? If so this what we already use so we were okay. Had to ask the original question though as I was kind of curious.
Chris Young
CYV Productions
Sydney -
I show the number to be 786.
Edward Troxel
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I suspected I wasn’t right for Vegas with 768. This is more of a feature of MJPEG and uncompressed capture cards. Which probably have engineers, not software purists behind them. So standards get misinterpreted. (a bit like Adobe getting the AVI headers wrong or truncated)
The important difference between established and calculated sizes is a history lesson in itself. Using the simplistic screen aspect ratio as a multiplier of the number of interlaced lines
(4/3)*576 = 768 but that of course doesn’t take into account the internal pecularities of Vegas.ie
(4/3)*480 = 640 not 655.655 isn’t the based on the simplistic screen area but pixel AR.
PAL pixel aspect ratio is 1.0925. 720*1.0925 = 786.6 which rounded makes 787×576. Set or crop to this then.The old SoFo tutorial said this:
“While your default PAL DV project is 720×576, SoFo suggests 787×576 for full-frame stills. Why? Because there is a difference between PAL DV pixels and standard graphics pixels.PAL DV pixels are wide, they have a “pixel aspect ratio” (PAR) of 1.0926, which means it takes more square graphics-pixels to fill the same width as a row of PAL DV pixels. ”
I guess a lot depends on what the digitiser is doing before you take what you need to be square-native in Vegas.
Perhaps true widescreen video makes this easier. 😉 -
Geez! maybe I shouldn’t have asked the question, got me confused now. Everything we have done in Vegas (PAL) using 768 x 576 looks fine. Draw a circle in Photoshop and and it appears as a perfect circle in Vegas.
In Photoshop when you create a new canvas the ‘preset sizes’ drop down menu gives PAL standard as 768 x 576 and widescreen as 1024 x 576. For NTSC 601 it is 720 x 540 and for NTSC DV/DVD it’s 720 x 534. There are also a host other NTSC widescreen settings for 601 and DV/DVD. Is anyone suggesting that these Photoshop specs are incorrect for Vegas?
Still confused!
Chris Young
CYV Productions
Sydney
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