Interlacing and Mastering

[greggerm]

Greetings!

I am a new SageTV user, and have the software tied in with my PVR-250. I've been using the (Good) and (Great) TV recording modes, and I've gathered up a collection of shows I'd like to burn off to DVD.

I have been playing with TMPGEnc to remaster my MPEG's down to a smaller size, and I seem to be messing up the interlacing. My remastered video, when played on the TV, seems to tear like the scan lines aren't meshing right. This happens primarily when there is a constant motion, like when the camera pans around.

I can tell TMPGEnc what to look for when it comes to interlacing, and I want to be sure I am doing it the best way possible. The questions are...

* Are the saved files from SageTV interlaced or non-interlaced?
* When prepping for DVD, should my final files be set up interlaced or non-interlaced?

If anyone has any recommendations for TMPGEnc settings, I'd be happy to see them as well! (Bitrate will need to be at a low 3200 kbps or so for all the material to fit)

Thanks to all who can lend a hand!
-Greg Germ

[stanger89]

Well, the files from SageTV are the same as the ones from WinTV 2000, it's the 250 that creates the MPEG stream, Sage/WinTV just write it to disk (doesn't really answer your question though huh).


To the best of my knowledge, the 250 creates interlaced files and your DVDs should be 29.97fps interlaced, you should probably set TMPG to not mess with the interlacing.

Good luck.

_________________________________________________________________

I wrote the rest of this before it sunk in that you already had the shows recorded.

What I would do, is choose one of the default DVD profiles when you record, those can be immediately writen to disk. You could create a custom DVD profile that uses 3200kbps as the bitrate and no re-encoding would be necessary.

You might want to consider this: use Womble MPEG VCR to edit the commercials, this is great, it can do frame accurate cuts without re-encoding the whole file, takes about 30min total to cut commercials from a 2hr show, then master the DVD in your favorite program ,ignoring warnings about it being too big, but don't burn it to disk just make the DVD on the harddrive, then run DVDShrink to make the "DVD" fit on a DVD-R. Sound kind of convoluded but should maintain the original file the best.

[thatdude90210]

Or try not messing with any of the mpeg settings at all, just author the DVD with the current mpegs. Don't use TMPGEnc, instead use something like "TMPGEnc DVD author" to edit out the commercials and author the DVD. Then use "DVD Shrink" to reduce the overall size to fit a DVDR before burning it.

[glbrown]

I can't seem to run raw sage files through anything without getting noticeably lower quality and it's driving me nuts. Take womble for instance.

Any sage mpg I touch results in a video that looks pretty good but has noticable pixelation on the fast scene changes. I have watched the same scene in the original and the copies for dozens of iterations and get the same effect. Womble writes fast so it shouldn't be re-encoding. It's always close but no cigar.

I have done these same tests with about a half a dozen different applications and they all show this same error. I have also noticed the mpg header file 'time' issue in a small percentage of sage files I have worked with.

The only 2 ways I feel comfortable archiving sage files is either direct copy to a data dvd or a binary split and copy for large files.

Something is rotten here and I haven't figured it out yet.

[greggerm]

In my case, I did cut the commercials out with Womble already, and that went spectacularly fast and well (no reencode needed). Unlike glbrown's experience, the only changes made to the resultant edited clips is no commercials - no technical issues have been encountered.

I needed to use TMPGenc because I needed to both change the resolution (mastering software won't do that) and lower the bitrate (while converting, might as well do it here rather than later) on my pre-recorded material. Unfortunately, I won't get the chance to record it again, so I'm stuck with the source material I made. (Future recordings will be made at a higher quality to avoid the issue)

Anyway - I figured out my encoding problem...

I was having the Interlacing system use the "B" field first, which is normally the case, but my captured video wanted the "A" field first. After comparing them head-to-head on a TV, the clip encoded with the "A" field first provided FAR smoother results with no scan line tearing. And yes, I needed to maintain Interlacing as (on) for both the source and destination.

Thanks,
-Greg