Pre-compress AVI before writing DVD?

[TakuSkan]

I'm wondering if I might get higher resolution in a finished DVD by 1st compressing the uncompressed source AVI with XVid, and then burning that to a DVD. I'm brand new at all this, so please bare with me if this sounds idiotic.

I was just watching the preview window while NeroVision Express 3 was writing my finished project. I immediately noticed the poor quality of the compressed video NE was creating from the uncompressed AVI source file. Aborting the process, and going into NE settings, I found I could change the settings and get a higher quality DVD in the end. My AVI was only 50 minutes long, and after applying the changes to the settings, NE reported it could burn 60 minutes of high quality data. I’m not getting any video in the preview pane at this point, so I hope this will work.

But I've seen AVIs where people have taken a half hour of uncompressed video, and probably used something like VirtualDub, AutoGK and XVid to shrink the source file to a 179-180MB file of outrageously good quality.

So my questions are:

1. Can someone point me to where I might learn how to convert my uncompressed 1/2 hour AVIs to XVid encoded files with that kind of high resolution at less than 200MB in size?

2. Can I make a higher resolution DVD video than I can get from NeroVision Express if I 1st compress my captured, uncompressed AVI video files with XVid, and then use some other DVD software to burn the disk?

I see where NE can export a video project to an Xvid encoded file. Maybe I can still do all of this in a series of steps using NE.

Many thanks,

TS

[CWR03]

1. You've answered your own question just above it: VirtualDub, AutoGK or GordianKnot; however you won't get any real quality with a file size of 200MB if it's an hour long.

2. Absolutely not. XviD is a lossy codec. If you're unsatisfied with NeroVision Express for burning a DVD from an AVI file, try something else, but XviD does not improve the quality of a file, it just works hard to minimize the loss of it while reducing file size.

[TakuSkan]

..however you won't get any real quality with a file size of 200MB if it's an hour long.
Not with 1 hour's worth of video, but I've seen 1/2 hour <200GB AVIs compressed with XVid that have extraordinary quality.

2. Absolutely not. XviD is a lossy codec. If you're unsatisfied with NeroVision Express for burning a DVD from an AVI file, try something else, but XviD does not improve the quality of a file, it just works hard to minimize the loss of it while reducing file size.
But NE is already using compression on files written to DVD video right out of the starting gate. I don't know what kind of compression it's using, but seeing how many different approaches there are to making a DVD video, and how NE can be set for different levels of quality via its limited compression settings, I'm wondering if there may be something that could compress and write higher quality DVDs than the copy of NE3 I've got here.

TS

PS: After a delay of quite some time, NE is now showing me the video it's writing in its preview window. I can already see how much higher quality the video is now compared to when I hadn't tweaked NE's quality/compression settings. So there are ways to configure compression settings to get a higher resolution DVD video in the end.

[ammck55]

I don't know what kind of compression it's using, but seeing how many different approaches there are to making a DVD video, and how NE can be set for different levels of quality via its limited compression settings, I'm wondering if there may be something that could compress and write higher quality DVDs than the copy of NE3 I've got here.
You might try setting up AutoGK and running some XviD tests, then compare them to the results you're getting from NeroVison Express. Capture a short test clip that will run through the respective encoders quickly. Sorting your naming conventions will help you a bunch, if your tests end up anything like mine, you'll wind up with a folder full of "test1.avi", "test2.avi", etc., and not remember your settings. Of course, you can always click on "details" view and be able to see the relative filesizes of the test clips, but it's always helped me to identify my tests in a slightly less random manner. Believe me, you'll open up a test folder from the night before and be wondering, "What the heck did I do, here?"

ammck55

[CWR03]

Good advice, ammck55, I usually have forgotten the settings before I can name the test .avs file using GordianKnot.

[TakuSkan]

You might try setting up AutoGK and running some XviD tests, then compare them to the results you're getting from NeroVison Express.Good idea.

Capture a short test clip that will run through the respective encoders quickly. Sorting your naming conventions will help you a bunch, if your tests end up anything like mine, you'll wind up with a folder full of "test1.avi", "test2.avi", etc., and not remember your settings.Ahhh.... Yes. Another good idea. I've done that in Photoshop saving files with names that attempt to identify the settings used like, SkaterSkybluerBodybrighter.bmp. Or changing those identifiers to codes to shorten file names like SkaterSbl2Bbr5.bmp ... etc. Sorting the files by date also gives me an idea which file was which in the process.

What I'm still trying to figure out is what the DVD burning apps like NeroVision Express do to pre-compressed video files when they burn them to disks. I've burned some of those 1/2 hour, 180MB XVid encoded AVIs I've found on the net to DVD disks with NE, and they look fantastic. Though the original captures were most likely much higher resolution than the VHS tapes I'm dealing with.

When making DVD videos from a couple of those XVid files, I've noticed that NE 1st has to prepare them for transcoding. That means taking pre-compressed files, and then transcoding them via a 2nd compression/decompression scheme to optimize fitting the data onto a 4.5GB DVD(SL).

So I guess my questions at this point are:

1. Are there other DVD video burning apps out there that might give me more control over creating higher quality DVDs from my uncompressed AVI captures than NeroVision Express?

2. Is it possible to get higher quality results from NE by preparing my uncompressed AVIs in some manner prior to crreating DVD videos with NE?

It seems every time a file is compressed or decompressed before DVD creation, it's going to loose some degree of quality. The shortest path from the original uncompressed AVI capture to DVD burning the better...right?

If that's true, unless there are other options for preparing AVIs for better end results, then the answer to #2 above would be 'no'... yes? :p If so, that leaves me back to wondering about #1.

TS

[setarip_old]

Is it possible to get higher quality results from NE by preparing my uncompressed AVIs in some manner prior to crreating DVD videos with NE?

Your uncompressed .AVIs contain ALL the pixels of information that you're starting with. If by "preparation" you mean some form of preliminary compression/conversion, that would seem to be illogical - you'd be losing information before you begin...

As a general statement, your original source material (VHS tapes) are low resolution to begin with, so you shouldn't expect great results upon capture and conversion...

[CWR03]

Is it possible to get higher quality results from NE by preparing my uncompressed AVIs in some manner prior to crreating DVD videos with NE?
As I stated way above, no. If by "higher quality results" you mean preserving or improving detail, as setarip_old indicated you cannot improve on your original capture. One of the reasons XviD-encoded files look so good is that they are post-processed for smoothness. If you turn off all post-processing, or set your video card to "No hardware accelleration," they'll look pretty bad. These filters aren't introduced into an encoded file, so if you encode to XviD (which, as I said, is a LOSSY codec) you will only lose quality and detail.

Again, as I stated in my first post in this thread, if you are unsatisfied with NeroVision Express, try something else. You can download trial versions of many of the best programs.

[ammck55]

TakuSkan->Yes, no, and yes. Or is that the other way 'round? I hope you're getting some idea of what you want to do, because I'm getting confused. :)

You say you've 30 minute uncompressed clips, so that's what? 6-7 GB files? Simply set up AutoGK and select the max filesize for your output and....see what happens. Run some tests like we talked about. You can exercise more control over your encode using the full Gordian Knot suite, but the setup and learning curve are a bit steeper.

Man, just grab a clip, run some tests, and report back on how you make out. I guarantee you that one long test session will teach you more about how to get this job done than a full week of batting hypotheticals around in the Forum. Not that it's not fun, it's just less productive than realtime experience. Go ahead on and make some.

Get stuck, post on that; you'll get some help.

ammck55

[TakuSkan]

Man, just grab a clip, run some tests, and report back on how you make out. I guarantee you that one long test session will teach you more about how to get this job done than a full week of batting hypotheticals around in the Forum.Agreed.

However I would like to 1st establish the objectives of the tests. And in my case, I don't think it's compressing an uncompressed AVI to the highest acceptable resolution at the smallest acceptable file size. Those are jobs for VirtualDub and AutoGK.

As I've noted, and CWR03 and setarip_old have confirmed, doing any kind of compression to my uncompressed AVIs before writing them to a DVD for playback in a standard home DVD player is only going to result in a loss of quality and detail.

So my objective would seem to be writing my uncompressed AVIs to a DVD-Video directly with the best resulting quality and detail.

From what I've learned while composing this, it appears the term "DVD-Video" is a precisely defined process. And it seems MPEG-2 compression is part of that definition as the chart on this 1st first URL I've found (http://www.dvdforum.org/hddvd-tech-intro-eng.htm) seems to spell out.

So I guess I need to learn what programs are available that give the most control over the many MPEG-2 settings that go into burning a DVD-Video. I think CWR03 offered the best advice there.

I'll continue to do some research on this. Meanwhile if anyone has any pointers or tips they might care to share, they'd surely be appreciated.

Thanks for getting me pointed in the right directions so far.

TS

[ammck55]

However I would like to 1st establish the objectives of the tests. And in my case, I don't think it's compressing an uncompressed AVI to the highest acceptable resolution at the smallest acceptable file size.
That's not what I suggested.

Your link goes to a site on HD DVD. Are you capturing an HDTV signal, if so, you could have mentioned that?

You've got several options. If you don't want any quality loss, burn the .avi files to disc--split the files if necessary. This will cause you no loss of the quality you have on capture. You could also go to Doom9's Guides page and find the guide for AVI to DVD under "Format Conversions" .

[setarip_old]

@TakuSkan

One set of procedures (other posters may/probably will suggest alternative methods) would be:

1) Use "TMPGEnc" (or "TMPGEncPlus") to convert the .AVI to compliant MPEG2-for-DVD format - Use "TMPGEnc's" DVD wizard/template to accomplish this

2) Use "TMPGEnc DVD Author" (a different program than "TMPGEnc") to easily create the required additional DVD files and structure (and chapters and a menu, if you wish)
You can obtain a FULLY functional free 30 day trial version of this commercial program at:

www.pegasys-inc.com/en/product/tda.html

**If the combined filesize of the DVD "package" written to your hard drive is greater than 4.37Gb, use DVD Shrink (or similar) to compress


If your O/S is either Win2000 or WinXP, TMPGEnc DVD Author can also burn your DVD. Otherwise, use NERO to burn in "DVD-Video" mode
(As an alternative to "TMPGEnc DVD Author", you could use "DVDLab")


Let us know of your success ;>}