Changing AVI Bitrate!

[Ace-Of-Spades]

I cant imagine this question to be too complex, anyway, i have a video (AVI/XVID) that plays pretty slow/laggy on my GPS, and i have been told that i could try lowering the bitrate of the AVI (video is currently 192kb/s (audio)). Would lowering the bitrate affect the video or audio of the avi? Also, how is this done in VirtualDub?

[jagabo]

Lowering the bitrate will lower the quality.

In VirtualDUb:

Video -> Fast Recompress
Video -> Compression...
Hilite the Xvid codec, press the Configure button
Set the desired bitrate

[Baldrick]

Or use AviRecomp or AutoGK.

[jman98]

Well, when you leave out important information, it becomes harder to help you.

What's GPS? I have the feeling you don't mean Global Positioning System.
If you do mean that, I've never heard of a GPS device that did anything but GPS, but I suppose should such a device exist, it probably has all kinds of limits on what it will play in terms of bit rate and resolution.

Knowing your video bit rate would have been helpful. I'm finding it hard to believe that 192 Kbps is anything other than your AUDIO bit rate. Perhaps you should take some time to learn to use Gspot and tell us what the video bit rate really is.

Some playback devices have problems with Xvid files that use video bit rates greater than 2000 Kbps. Some don't like large file sizes (anything above 2 GB). Your resolution could also be a problem (anything over 720x576 is not likely to play correctly, if at all). Your playback device, whatever it is, may have documentation that explains what it supports.

[PuzZLeR]

Making a photocopy of a document will never be as good as the original no matter how good the machine. The best you can hope for is something that is almost as good. At least according to the naked eye.

That's how video is with lossy codecs like Xvid. You would actually need to add about 5%-10% more bitrate on a re-encode to get a quality difference that isn't noticable.

But if your GPS is a small screen you could get away with it, even reducing it by 50%, depending on the original. You don't have to re-encode the audio - you can just demux it from the original and remux it with the new file.

About VirtualDub, if I may add, before you begin:

Load your clip (drag and drop)
Go to File -> File Information
Check out the Average Bitrate and figure out what you need for the encode.
Then follow Jagabo's steps.

[Ace-Of-Spades]

Thanks for the replies people. Firstly, i do mean GPS as in a navigator, i was able to pick one up that had a few extra features including playing videos (WMV, AVI and ASF).

The AVI/XVID i am talking about has 950kbps (according to GSPOT), and it played very jerky, however when i converted it to ASF it seems to play fairly well on the GPS. The output ASF has a bitrate of 619kbps.