How to Shorten an AVI file

[ukcalibrauk]

I want to shorten an AVI (DIVX) file by a few minutes, without cutting.

Is there an easy way of recompiling it so it is xx minutes shorter by losing just a little bit of quality

Thanks

Calibra

[Ostaf]

bluh?
The only way I know of to shorten it without cutting is to increase the frame rate (ie, if it is 15 fps, seting the frame rate to 30fps will cause it to play twice as fast)
There's a program called FRate which will let you do this, if that's really what you want.
To shorten it by a few minutes may only require increasing it by 1 or 2 (or even less) frames, so you'd have to experiment, or calculate it.
Bare in mind that this only changes the video, not the audio rate, so you'll lose A/V Synch. To shorten the audio requires other tools.

[ukcalibrauk]

Sorry this option is no good

I thought that when a DVI (DIVX) file is created, a quality level is selected.

So I would have thought that if I recompile it at a slightly lower quality that would shorten the file size slightly

But I don't know how


Calibra

[PhArAoH]

So I would have thought that if I recompile it at a slightly lower quality that would shorten the file size slightly

But I don't know how


Calibra

You can use VirtualDub to re-encode the video using lower bitrate (use a bitrate calculator) but keep in mind that this will reduce the quality of your video.

[ukcalibrauk]

Bit rate calculator, where and what is the best

Also any chance of a step by step guide on how to carry out a recompile at a different sample rate with virtualdub

Thanks

[PhArAoH]

I use AVI/(X)(S)VCD Bitrate Calculator from http://www.tomzavodny.cz/program/bitcalc/index_en.php & Advanced DivX BitRate Calc! from http://www.doom9.org
Use one o fthe above to calculate the bitrate required based on the length of the video and the final filesize you want. Once you know the bitrate do the following:
1. Start Virtualdub
2. File->Open video file
3. Select the file you want to encode
4. Click Video->Compression and select DivX Pro 5.02 (or whatever version you're using) from the list of codecs and click on Configure button. You can now use the slider to adjust the bitrate to the one you were given by the Bitrate calculator or just type the value in the kbps box.
5. Click on OK button and you're back to the Select Video Compression dialog. Click OK.
6. Click on File->Save as AVI and type in the name of the output file.
7. Click on SAVE button.



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[ukcalibrauk]

I'll give it a go

Calibra