convert .ogv to .avi (ubuntu)

mencoder noise1.ogv -ovc xvid -oac mp3lame -xvidencopts pass=1 -o noise1.avi

VirtualDub: Joining AVI files

From : 

http://www.afterdawn.com/guides/archive/virtualdub_join_avi.cfm

Step. 1 - File --> Open Video File

Launch VirtualDub and open the first AVI file in the sequence of videos you want to join by selecting File--> Open video file.

Step. 2 - Open First AVI file

Find the first AVI file, select it and then click Open. You will now see it open in VirtualDUB. If the program says it's unable to locate a decompressor, then you will have to find the appropriate codec at AfterDawn. I recommend you install FFDShow.

Step. 3 - Scroll to the end of the file

Drag the slider straight to the end of the video stream. Make sure it is set on the very last frame.

Step. 4 - File --> Append AVI Segment

Now after you have made sure the last frame is selected, click File --> Append AVI Segment and the File Browser will pop up again.

Common Sampling Rate Error?

Have you received an error informing you that the two AVI segments do not share a common sampling rate? This is often due to VirtualDUB automatically re-writing the audio header of the first AVI file if it is VBR MP3. If you have received this error, then close VirtualDUB now as you will not be able to continue with this method, but you will be able to with the guide link below, otherwise move to Step 5.


Join AVI files with VBR MP3 audio using VirtualDUBMOD:
http://www.afterdawn.com/guides/archive/join_avi_files_with_vbr_mp3_audio_using_virtualdubmod.cfm 

Step. 5 - Open Second AVI file

Locate the second AVI file, select it and click Open, the second file should now be added to the end of the first file. Now this is where you will get problems if you have file with separate framerates, resolutions or codecs.

Step. 6 - Video --> Direct Stream Copy

Now we have to make sure that you don't end up with decompressed Video (which would probably result in a file 100's of GB's in size). Click Video --> Direct Stream Copy. This is very important, do not forget this.

Step. 7 - Audio --> Direct Stream Copy

Just as we had to with Video, we just have to make sure that you won't wind up with uncompressed Audio (LPCM). Click Audio --> Direct Stream Copy. This is very important, do not forget this.

Step. 8 - File --> Save As AVI

Now you are ready to save an AVI file. Click File --> Save As AVI, select where you want to save a new AVI file and then it will only take a few minutes at most to save it.

Finally

Hopefully this will have helped you to join two AVI files together. If you have any problems or questions, please visit our Discussion Forums to ask there. 

Version History

v1.0 -- 19th November, 2003, First version online (JK) 
v2.0 -- 9th February, 2005, Updated to most recent version, fixed problem causing uncompressed Video. (Dela) 
v2.1 -- 6th March, 2007, Added Virtual Dub Mp3 Freeze as troubleshooter. (DVDBack23) 
v2.2 -- 10th May, 2008, Removed VirtualDUB MP3 Freeze reference and added link to AfterDawn guide for VirtualDUBMOD to counter sampling rate error. (Dela)