[VirtualDub]

After decompressing the AC3-stream to an uncompressed Windows-WAV-format it is now time to get Video and Audio back together using the MP3 compression:

• Download the VirtualDub Package
  
• Unpack into a directory of your choice
  
• Fire up VirtualDub.exe
  
• Open your Videostream AVI with File->Open video file menu.
  
• Open your Audiostream with Audio->WAV Audio... menu.
  
• Choose the menuitem Video->Frame Rate....
  
• Change the fps value so video and audio durations match
  (In case it shows the same as input-framerate just leave the settings)
  
• Choose the menuitem Video->Direct Stream Copy.
  
• Choose the menuitem Audio->Interleaving....
  
• Set both milisecond values to 4000
  
• Choose the menuitem Audio->Compression....
  
• Choose MPEG Layer-3 as Format and desired bitrate at Attribute.
  (I would recommend 160KBit/s for high quality)
  
  or you may alternatively use OGG Vorbis as Format.
  (here I would use significantly lower bitrates ~80 Kbit/s - ~128 Kbis/s)
  
  NOTE:
  This value has to match the audio-bitrate you used when calculating the video-bitrate using the bitrate-calculator !!!
  
  
• Choose the menuitem Audio->Full processing mode.
  For a 2 Disc compression do the following:
  
  a)Choose the menuitem Video->Select Range...
  b)For 1st CD change Length to half of original length
  b)For 2nd CD change Start offset to half of original length
  c)Save both files with the step below
  
  
• Save your multiplexed stream with File->Save AVI....
• This process takes some time since audio compression is done
  (My Athlon 500 needed 2 hours for a 2 hour movie)
  

NOTE:
In case your Video-AVI file ended up being a lot smaller than you expected (this sometimes happens when the video is extremely dark and the codec does not need the bitrate you gave it) you should use a higher bitrate for audio since this will increase quality and reduct MPEG artefacts.