What bitrate to use

NOKNOT wrote on 8/2/2010, 6:56 PM
I have been posting several questions but I am trying to understand this process better. I have read in some of the comments that the bit rate determined the size and quality of the finished product. I have been using VSM 10 and Ulead Studio 11.5. I have several mini dvd tapes an hour long I have been converting to DVD. The last one I thought I would do the same project on both Softwares. I burnt to a file from both and then burnt to DVD from file . The project size from Ulead was 3.5gb and the file from VMS was 2.7gb. I have no idea what the settings are for VMS, I guess they are at default. Should I change something to make the size bigger or not? As I have said I am trying to learn more about this. Thanks for all your help.

Comments

Chienworks wrote on 8/2/2010, 7:46 PM
Apparently, according to rumor, version 10 now has the ability to allow the user to set custom MPEG2 bitrates when rendering. Previous versions did not allow this. If this is not true then ignore the following.

Good rule of thumb is to divide 600 by the length of the video in minutes and use the resulting number for the average Mbps rate, up to about 8.5Mbps maximum. 600 / 60 minutes is 10, which is over the maximum so stick with 8.5. For anything over 6 you might as well use a constant bitrate as there isn't much to be gained from VBR encoding. Subtract about 0.2 for the AC3 audio, which leaves a CBR of 8.3Mbps. This won't fill the disc, but a higher bitrate may cause skipping and other problems in a lot of players.

Let's say your project was 105 minutes instead. 600 / 105 = 5.714. Subtract 0.2 for audio and you're left with about 5.5Mbps. This is less than 6 so you may want to consider VBR. Set the maximum bitrate for 8,500,000, the average for 5,500,000 and the minimum for, oh, probably not less than 1,000,000 (some players have trouble if the bitrate drops too low). Chose 2 pass encoding. Vegas will now distribute the bits so that more are used where needed for fast action and less for more static scenes and will produce a file that pretty closely fills the disc.

Also keep in mind any menus you wish to create and add them to the length of your project. If you intend to have about 5 minutes worth of menus then you must take this into account when doing the calculations.
musicvid10 wrote on 8/2/2010, 8:41 PM
[i]"If this is not true then ignore the following."

It is true and Kelly, you really should download the 30 day trial and give it a test drive. Fun stuff!
MSmart wrote on 8/2/2010, 9:21 PM
Hmm, I hadn't thought about it since I always render to .avi, but yep, v10 has opened the flood gates to customization of mpeg renders Here's what it looks like:

Custom Settings

Unless I'm wrong, VBR with 6Mbps average is the default. At least that's what came up when going into the Custom settings window.
NOKNOT wrote on 8/5/2010, 12:49 PM
I created another project. This time instead of checking Burn to DVD and going straight into DVD Architect, I burnt it to a folder. After loading from folder and allowing DVD Architect to do all the rendering the movie came out about 3.5gb. Does VMS render or compress before sending to DVD Architect, and if so is there an advantage to doing it that way? Thanks.