View Full Version : Please Help me Understand...


Tom Marks
March 7th, 2008, 09:37 AM
OK...I'm a bit confused and I'm not surprised b/c all this is new to me. I just started out with a Canon HG10 and I'm learning how to edit my movies. Not bad so far. I have reached a point now that I would like to take my projects and put them on DVD. It was my understanding that the format that a DVD player reads is MPEG-2. I burned a DVD from a file that was coded Mpeg-2 and I did the standard 720 x 480 NTSC DVD format and my footage looked like garbage.
Last night I was playing around with Sony Vegas DVD archietect and just wanted to create a DVD Menu with some background music. The events that I have saved in 1280 X 720 are in WMV format. I use this to submit my projects onto Vimeo.com. I took these projects encoded in wmv and put them on my menu. I burned the DVD and to my surprise the buttons I created actually lead me in to my movies. The movies looked much better than the first DVD I ever burned. Does this software take any format and convert it so a standard DVD player can read it? I was under the assumption it was only MPEG-2. I gues for now I will be saving my movies in WMV instead of MPEG-2. The quality is night and day.
Ideally, I want to get a Blue ray burner and format my movies in 1920 x 1080 and burn that onto a BD disk.
Can someone explain this Mpeg-2 codec versus the other ones? Which one do you use? If your creating very clean movies that are clear almost High-def how are you doing it?

Seth Bloombaum
March 7th, 2008, 11:09 AM
Welcome to the somewhat arcane world of optimizing video for DVD - there's a lot of stuff that's not obvious.

First, yes, DVD Architect will accept many file formats and convert them to MPEG2 without much bother. This is a great place to start. To get optimum results from this process, give DVDA a video file that hasn't already been compressed very much - for example, a DV-AVI, Cineform (not sure if this works into DVDA, but if it does it would be a great choice), as a second choice a high bitrate WMV is not horrible (say, 4 megabits per second or above).

There are a couple issues that serious-minded tech video hounds have with this approach - first, there are no buttons to push, no controls to set, no dials to adjust. That's just plain offensive to some of us. Second, there is no way to preview the results until it is done. With these two issues in mind, there is no way for the user to optimize the video compression in any way.

But it is simple, it is straightforward, it's fairly bullet-proof, the compression is automatically adjusted so your video fits on the dvd, you don't make many coasters with this method (coaster = a bad DVD, now only suitable for putting under your coffee cup).

Doing an encode to MPEG2 in Vegas offers many rewards, but also takes patience and some specific expertise. Here's a rough outline of the steps:

1) Look at the combined length of all video, consult a bitrate chart and select a compression setting/bitrate.

2) Render as "Mainconcept MPEG2 for DVD Architect". If the footage on the timeline is anything but 720x480 standard def, go into the custom dialog and select "Best" video quality. Review the other 20 settings and see if you want to change anything. Press "Save" and go have lunch.

3) Render the audio separately as AC-3 Dolby Digital. There are some "custom" settings that need to be changed - a quick search on this forum will find them.

4) Now, you're ready to import those files into DVDA...

A big concern is getting that bitrate correct in step 1. If DVDA sees that your MPEG2 file(s) is too large for the DVD, it will recompress, which is a huge quality hit, and may be what you've already experienced with rendering MPEG2 out of Vegas.

I highly recommend downloading and reading Edward Troxel's newsletters. (http://www.jetdv.com) They answer a lot of common questions, and one of them has a dvd bitrate chart.

Jim Browning
March 7th, 2008, 11:37 AM
It could have just been the settings I used on my first attempts, but I found that doing the compression within Vegas (using the settings Seth mentions) took far less time than doing it within DVDA. As in 1 hour or less in Vegas vs. 5+ hours in DVDA to render a video close to max DVD capacity.

I haven't come close to trying many alternative work-flows, but I like rendering within Vegas to files that don't have to be recompressed by DVDA. For me, that puts the different functions where it seems they ought to be: Rendering in Vegas; DVD creation in DVDA. You have all the tweaks you need to control the rendering in Vegas. In my case that gets me widescreen anamorphic video and the audio I want in separate streams. DVDA recognizes the separate streams automatically (took me awhile to realize that!) and creates a nice DVD in just a few minutes because there is no recompression. I haven't compared it to feeding DVDA a WMV, but I suspect it will compare just fine; that Seth is right and you had DVDA recompressing compressed footage.

But your having said what you said means I just have to try it now... so thanks for causing me to spend the extra time when I thought I was doing just fine! :-P~~~

Brian Luce
March 7th, 2008, 11:43 AM
1) Look at the combined length of all video, consult a bitrate chart and select a compression setting/bitrate.

.

This is the part I'm weak on...

Where do you get these charts? And by length do you really mean file size?

Don Bloom
March 7th, 2008, 03:48 PM
check Edwards newsletters for the bitrate chart as Set suggested. The "length" of the file is the TIME-IOW, 60 minutes, 75 minutes 115 minutes etc from the timeline in Vegas. With the right bitrate and settings I have run up to 3 hours on a single layer DVD-(seminars) where the quality hit isn't a big deal. Lower bitrate = lower quality but I run 2 hours all the time at a bitrate in the mid 4s and the quality is fine. Remember to render the audio to AC3-the file is a smaller size and allows for a higher bitrate.
Edwards newletters have a ton of info about preparing for DVDA.
Don

Mike Kujbida
March 7th, 2008, 06:04 PM
Here's a link (http://www.johncline.com/bitcalc110.zip) to the DVD bitrate calculator I use all the time.
Note that this links to a zipped file.