Question about bitrate??

gr77 wrote on 11/20/2008, 1:11 AM
Hi, I was just wondering if there are any "common rules" of what bitrate you should use on different projects??

I burned a project of about 26 minutes, and the default bitrate was set to 8,000. The DVD froze after about 19 minutes when I played it. (This has happened to me alot). I then changed the bitrate for the movie files to 5,676 and it burned successfully. I did the exact same thing with a project of about little over 60 minutes. It also burned successfully.

Now I am doing the same thing with a new project of about 35 minutes. I have changed the bitrate, but now it freezes after 19.45 minutes. How do I know what bitrate to use??

I have rendered the projects with Vegas Movie Studio Platinum 8.0 using MPEG files and AC3 sound.

I live in Europe, so I use PAL and 5.1-surround.

I hope someone can help me.

Comments

johnmeyer wrote on 11/20/2008, 7:44 AM
Most freezing of the type you describe is due to bad media.

No, let me amend that: ALL freezing is due to bad media.

Players are designed to playback a sustained bitrate (audio + video + subtitles) of over 10,000 kbps. The 8,000 average bitrate should work just fine. Here's a link to the official site (mpeg.org) where this is described:

mpeg.org (Document describing DVD spec and maximum bitrates)

Note the following quote from this document:

"Contrary to popular belief: all DVD players are required to decode video streams up to 9.8 Mbit/sec for indefinite periods of time. The popular average rate of 3.5 Mbit/sec or 4.7 Mbit/sec are merely canonical figures created by the notion that only single sided, single layer discs will hold feature length films. Should Single Sided, Double Layer discs prevail, the average rate would be almost twice as great. ALL DVD PLAYERS MUST SUSTAIN A 9.8 MBIT/SEC VIDEO DECODE RATE!!!!!!! Hardwired (Application Specific Integrated Circuits---ASICs) implementations of MPEG-2 MP@ML decoders are generally capable of handling 15 mbit/sec sustained rates."

Try again using Taiyo-Yuden 8x DVD-R or Verbatim brand media. Make sure in both cases that it is the PREMIUM brand and not the "value" or discount version.

Lots of people will tell you that bitrate matters, but I have never once -- through actual testing -- been able to find any evidence of this, and in fact all evidence says that this is not true. However, almost everyone in this forum and elsewhere has had experience with lousy media. 90% or more of the media being sold is not very good. Sad, but true. You have to go out of your way in order to find and get the good stuff.

This is what I buy:

Taiyo-Yuden DVD-R White Hub Inkjet Printable 8x


gr77 wrote on 11/20/2008, 9:59 AM
Well, I am certainly willing to try changing my media!

However, I do have the following question to you:
Why did my previous projects burn successfully when I changed the bitrate, and not when I used the default? I have tried changing it back again, and it freezes at the exact same moment. I have used Sony DVD+R 8x media every time. I have also been able to make more than one copies of my succesful projects. Why wouldn`t the media freeze then?

I am just asking because I do not know too much about bitrates and what type of media which is best to use...
johnmeyer wrote on 11/20/2008, 12:28 PM
Every media has errors that must be corrected. Download and run the free utility, DVD Speed:

nero dvd speed

and test a few of your DVDs. You will be amazed at how many errors are reported.

The higher the bitrate, the more of these errors must be corrected each second. If enough errors occur, the player can no longer correct and you either get a visible glitch, or eventually a freeze. Thus a "solution" to using bad media is to use a lower bitrate.

Since every blank disc is a little different, and that variation between discs is usually even more pronounced when quality control is lacking, you can get different results with each burn.

Also, make sure not to change most of the settings from the defaults. Start with one of the DVD Architect templates when encoding in Vegas, and only change the Average bitrate. Leave everything else alone. In particular, don't mess with the minimum and maximum bitrates. Leave them set at their defaults.
Aivar wrote on 11/20/2008, 4:48 PM
I think, it's not about the bitrate, try to burn on minimum speed, and use quality media, like Verbatim :D
gr77 wrote on 11/21/2008, 12:30 AM
Thank you for your answers and tips!
I will buy some new quality media and see what happens.
gr77 wrote on 11/27/2008, 2:02 AM
Hi again!

Just wanted to thank you for your tips again. I have tried burning my projects on Verbatim discs and it works perfectly!

But isn`t that a little shout out to Sony?? Their discs will not burn projects from their own software...