smart rendering not working for some VHS captures

emjaysea wrote on 8/1/2014, 10:23 AM

(Perhaps this should be titled "How do I losslessly split an MPEG-2 file," because that's ultimately what I'm trying to do here...)

As the subject indicates, using Vegas Pro 11 64-bit, I'm unable to get smart rendering to do its thing with some long mpeg-2 files captured from VHS tape. First of all, I open the 6+ gb file in Vegas, mark it at one hour, split it, cut the remainder off and paste that into a new instance of Vegas pro with the same project settings. Then regardless if I'm working with the new instance or the original, I make sure smart rendering is enabled, the project settings are based on the video file, and when I render I check the "Use project settings" box, but then it takes 15 minutes to render the hour long video and it's definitely not a smart render.

Any ideas? Thanks!

Video Properties:
http://i.imgur.com/UJ47Y4Z.png

Project Properties:
http://i.imgur.com/JpIZ9Wd.png

Comments

Former user wrote on 8/1/2014, 10:41 AM

I think the Use project settings is the problem. You need to set your MPEG output settings to match the original file. Bitrates have to match as well.

emjaysea wrote on 8/1/2014, 12:04 PM

Thanks for the response, Dave. So, if they have a variable bit rate, am I out of luck? I suppose I can try the average...

musicvid10 wrote on 8/1/2014, 12:54 PM

No, you are not out of luck.
Match the bitrate(s), field order, aspect, frame rate, and everything else same as your SOURCE (not project properties!) and it will work.
Keep trying short renders until you get it.

Caution: At your cut points, Vegas may render a couple of frames to set the GOP to an i-frame (may or may not be noticeable).

emjaysea wrote on 8/1/2014, 2:12 PM

I will try that. But I'm unclear why, since I base my project settings on the video files themselves (you know, you do a Ctrl+N to create a new file, and in the New Project dialogue that comes up you can click the Match Media Settings icon in the upper right corner, navigate to the file you'll be editing and select that). Seems as though that would set the project settings to be identical to the source--what the heck else does it do, if not that?

Here's what my capture settings look like--see anything outside of Vegas Pro's typical purview? http://i.imgur.com/V4OC9kS.png

musicvid10 wrote on 8/1/2014, 2:32 PM

1. Get your media properties in MEDIAINFO. The properties you posted are incomplete. No bitrates, no field order, no aspect, etc., etc., etc., etc., etc.,
2. Input those properties exactly into Render Properties.
3. There are really no guessing games about this. Best of luck.

Former user wrote on 8/1/2014, 2:55 PM

Project properties does not read bitrates. That is why you can mix formats on the timeline.

emjaysea wrote on 8/4/2014, 11:55 AM

Thanks. That worked (getting the message No Recompression Required), although the file indicates it's still gonna take 8 minutes to render...

For anyone trying to figure this out, the original video had variable bit rate compression, so that's what I've chosen in Vegas, too. I set the maximum to what MediaInfo said was the max in the original, the average to the MediaInfo average, and then chose what looked like a good minimum, likely to produce the same average. It appears to be working.

UPDATE: Nope, didn't work. Close, but no cigar. I wanted to see if this could be done on a file that hadn't been split, just to see what's going on, so I opened a file, set its render settings according to MediaInfo and rendered it. Here's a comparison between the two MediaInfo readings. http://disposablewebpage.com/turn/e8Ye88S44h This page will only be available for 90 days, but the meat of the difference is in the bit rate. Original File: 7196 Kbps, Re-Rendered File: 6944 Kbps

Chienworks wrote on 8/4/2014, 12:03 PM

This is where Vegas really needs a button for "i'm gonna smart render this, so go find out all the settings for me and use them." The user shouldn't even have to know there are settings to be, well ... set.

emjaysea wrote on 8/4/2014, 1:54 PM

Yes, Chienworks, I agree. This is st00pid, and not worth my time.

farss wrote on 8/4/2014, 2:46 PM

Capturing VHS to mpeg-2 is where your problem started. You should have captured to DV which would have avoided this problem and the risk of loss of quality.
You could try using a tool custom written to handle the issues of editing mpeg-2 such as Womble to edit the files with as little loss as possible.

Bob.