Variable Bit Rate

Ken Veal · Post by **Ken Veal** » Mon Mar 30, 2009 10:48 pm

I have set a VBR of 7000 in the project options Comp tab.
Before capturing I noticed that on hovering over the "720x576 DVD Variable Bit R......." field in the Information window-
a DVD VBR of 9000Kbps shows up.
Why is there a difference
Do I need to alter the 9000
If so how ........................Ken

DVDDoug · Post by **DVDDoug** » Mon Mar 30, 2009 11:20 pm

There's a difference because you've choosen project settings that are different from the video you're importing.

You don't need to lower the bitrate unless you're running out of disc space.

Since you're (apparently) importing video from a DVD, you can check the box that says "Do Not Convert Compliant MPEGs" (on the burn screen). This will preserve the original quality and will make the process faster. (This may not work if you have clips from different DVDs with different settings.)

Note that some DVD players may have trouble playing "burned" DVDs with bitrates higher than around 7000kbps. (And, tbe DVD spec sets a limit of 9800kbps for video, and a limit of about 10,000kbps for combined video, audio, and subtitles.

Ken Veal · Post by **Ken Veal** » Tue Mar 31, 2009 7:56 pm

Thanks for the reply, if it makes any difference I am capturing from
a Panasonic NV-MX500B camcorder that uses mini dv tape that has video that I recorded on it.In all the time I have been using this cam it is the first
time I have noticed this data in the information window,so your reply has re assured me

DVDDoug · Post by **DVDDoug** » Wed Apr 01, 2009 12:01 am

Panasonic NV-MX500B camcorder that uses mini dv tape that has video that I recorded on it.

In that case, I' might be wrong!

I don't know what that 9000 number means... I was thinking you imported video from a DVD, and that your imported video was 9000kbps MPEG-2.

Generally, video "captured" from a MiniDV camera is captured to DV/AVI, which has a much higher bitrate (somewhere around 28,000kbps) and therefore much bigger files (13GB per hour). If that's the case, the
Do Not convert box will be ignored.

If you captured to MPEG-2 (converting from DV on-the-fly), then you can still use the Do Not Convert option as long as the program will fit on the DVD at that bitrate.

Ken Veal · Post by **Ken Veal** » Wed Apr 01, 2009 10:56 pm

I capture to DV AVI.
So where does the computer get this 9000 figure from, it must be generated by the camcorder I presume?

sjj1805 · Post by **sjj1805** » Thu Apr 02, 2009 1:41 am

No it does not get it from the camcorder.
The Variable Bit Rate is as its names implies variable.
Some parts of the video (with little movement - such as a fixed shot of a building) will have a low bit rate. Other parts with lots of movement - such as a racing car driving past will have a high bit rate. What is more important is the average bit rate. Many stand alone DVD players struggle if the bit rate is too high.

Normally I would use a constant bit rate. You only need to use a variable bit rate if the DVD is a bit too big to fit onto the disc and you need to cut it down a bit. If you do go for a variable bit rate you will also get better results by selecting the 2 pass option.

Trevor Andrew · Post by **Trevor Andrew** » Thu Apr 02, 2009 10:14 am

Hi Kenneth

Make sure you are selecting DV as the capture format not DVD.
DV is at the top of the list above AV, sometimes this does not show without scrolling up.

When you select DVD the info line showing the bit rate is not large enough to display all the detail.
Floating your mouse will show all as a tool tip.
If it shows a bit rate then you have not selected DV.

When I select DV I see (720x576,DV Type-1,PAL )

Ken Veal · Post by **Ken Veal** » Fri Apr 03, 2009 1:31 am

When cam is connected I click the options cog in VS11+ and bring up the Video Properties Box.On clicking the down arrow and scroll through the options they all start with DVD Pal.Am I looking in the wrong place to set the capture Format ?
In the capture screen the format is set at DVD and greyed out until the cam is connected , when connected up the drop down arrow does not respond.
Where do I set the capture format and how.
Would this present setting be the possible cause of playback glitches as
posted here ?

http://forum.corel.com/EN/viewtopic.php?p=176256#176256
I use VBR because it was advised in "Recommended Proiceedures for Success with VS"
The last I used 2 pass ,rendering took several times longerand I could not see any improvement .......................Ken

Post by **Ron P.** » Fri Apr 03, 2009 1:50 am

Where do I set the capture format and how.

Click on the 2 screenshots to enlarge..

Trevor Andrew · Post by **Trevor Andrew** » Fri Apr 03, 2009 9:43 am

Hi Kenneth

Once you are looking at the Video and Audio Properties box....press Advanced
This opens a window allowing you to set the capture properties.

View my quick guides from the link below, although written a while ago, is still relevant for newer versions.

http://uk.geocities.com/trevor.andrew@b ... e_mpeg.htm

By the way I use Constant, buts that¡¦s just a personal choice.

skier-hughes · Post by **skier-hughes** » Fri Apr 03, 2009 9:48 am

What is the make and model of cam and how is it connected?

Ken Veal · Post by **Ken Veal** » Fri Apr 03, 2009 11:36 am

I have a Panasonic NV-MX500B ,firewire connection to PC

Ken Veal · Post by **Ken Veal** » Fri Apr 03, 2009 11:39 am

The drop down arrow the format field is not responding

Post by **Ron P.** » Fri Apr 03, 2009 11:50 am

Trevor, Kenneth is using VS11.5+, and the Capture properties dialogs are somewhat different than VS8,9,and 10+. The screenshots I provided are from VS11.5+.

Post by **Ron P.** » Fri Apr 03, 2009 11:55 am

Kenneth,
What does it show in the Source box? It should be something like Panasonic DV Device. Also what does the Device Control show? (Tools menu>Select Device Control).

Alludo USER to USER Web Board

Variable Bit Rate

Variable Bit Rate

Inported video

9000bps

Capture format

CAM SPEC

Capture Format