video and audio rendering

JJack wrote on 5/4/2003, 1:15 PM
Here's my situation. I have just started burning CDs. One problem after another. Most of my work at this time is converting home movies and old VHS tapes for customers. I want to be able to get 2 hrs. on a DVD -- it can be done. Corresponded with expert Ralph LaBarge who said to get my bit rates down under 4.5 and compress audio with AC-3. So, I bought DVD Architect.

Here's what's happening. I have a project with seven files. In VV4 I rendered video type MainConcept MPEG-2 with template: DVD Architect NTSC video stream. I then re-rendered for the audio, type Sonic Foundry AC-3, template Stereo DVD (only option in the drop down menu. These steps recommended per tech support.

When I transfer rendered files to DVD Architect, set up my seven-file menu, and bring up the Optimize DVD screen, here is what I get. I have 5.091 MB = 126% of a 3,95 disc. Ok, I expected that. The default bit rate is 8.4mbps. Now I don't need that rate, given the low quality of the original material I'm working with. So, I'll lower the bit rates of each file down to 4.5 and everything will fit -- right?

The DVD Architect manual on p. 29, paragraph 3 ADJUST VIDEO SETTINGS AS DESIRED says I can select each file, select the Recompress video and then select the Override default bitrate check box and drag the slider to pick a new bitrate. Well, the slider has no effect whatsoever. How come? Any thoughts on this?

Secondly,on the Optimize DVD screen, when it first comes up, all 7 audio files are on automatic and have green checks. Only one of these files is AC-3 stereo, the other 6 are AC-3 5.1., even though I rendered them in VV$ as AC-3 stereo. (Any thoughts on that?) When I change each file to AC-3, the green check turns yellow and I now have to re-render these files during dvd burn. I discovered that during the burn.

Am I right, the program does not work as advertised.

I ran all the above through telephone tech support but really didn't get much help, just alot of toe dancing around.

Comments

swattum wrote on 5/5/2003, 3:01 PM
Not trying to defend the problems you've encountered with DVDA, but just a suggestion that you'll be much better off rendering directly from Vegas at a lower rate than letting DVDA re-render for you. MPEG2 is a lossy compression, so when DVDA has to re-render you're already starting with lower quality material than what you originally had in Vegas.

As far as the AC3 stereo/5.1 deal - a number of people on this forum have noticed this (myself included); it doesn't seem to matter in the final output that I've produced so far. Every AC3 stereo thing I've rendered comes out looking like 5.1 not only to DVDA but to my receiver as well - so I quit worrying about it.
jetdv wrote on 5/5/2003, 3:09 PM
How long is your video? You need to adjust the bitrate in Vegas when you render to the MPEG2 file to be appropriate for your length. If the length of your video requires a bitrate of 6,000,000 to fit on a DVD and you render at 8,000,000 then it, definitely, won't fit.

Here's the technical formula to determine the bitrate for video with AC-3 audio.

=(36096 - (((Length in Minutes * 60) * 192) / 1024)) / (Length in Minutes * 60)
JJack wrote on 5/6/2003, 9:55 AM
Yes, I'd like to do my rendering in VV at a lower bit rate and eliminate rerendering. However, at the present time, when you select DVD Architect NTSC streaming video to do a video only render in order to do a second render for AC-3 audio, you do not have a choice of bit rates. I explained this to the tech support person who agreed this was not good and should be changed.

Secondly, since I wrote the original message I went ahead and used the 5.1 AC-3 audio and it sounds ok, so I did not rerender to stereo. Wierd workaround!
JJack wrote on 5/6/2003, 10:13 AM
I understand. I rerendered in DVD Arch in order to get file sizes that would permit me to get 120 minutes on the DVD, which I did. Thanks for the formula.
swattum wrote on 5/6/2003, 12:00 PM
I'm not sure what you are refering too. When you select the DVDA NTSC template, then select custom... select the video tab from the new dialog and then select the average bitrate that you want.
JJack wrote on 5/7/2003, 10:24 AM
No, that's not it. I said I selected DVD NTSC streaming, which gives you video without audio, and in this selection there is no bit rate adjust option. Re-read my previous posts, for all the details. OK? Tech help has admitted this to be a design flaw and "hopes" to solve this in an update where, if you select the streaming option, you will also have the ability to adjust bit rates, eliminating rerendering. This has only been an issue for me where I'm trying to get 120 minutes on a DVD. For shorter burns, I just go with the defaul templated and use uncompressed audio.
swattum wrote on 5/7/2003, 5:04 PM
If you look just to the right of the template drop-down you should see a button labeled "custom..." - click on it. This will open up another tabbed dialog; along the bottom are the tabs, select "video" and select a lower bitrate from that page.

Every NTSC option that I see for MPEG-2 rendering using MainConcept allows me to set up the bitrate for the encoding. if you aren't seeing this ability, then I don't know what else to suggest.
craftech wrote on 5/20/2003, 7:02 AM
How does it look with 120 minutes on a DVD?

John
jetdv wrote on 5/20/2003, 9:16 AM
I think it looks fine. You DO need AC-3 audio to keep the bitrate at a reasonable level. With AC-3, two hours can still be at a 4,800,000 bitrate.