How do I convert my avi videos for ipad?

[baba]

I have installed the m4a-codec, expecting that this would enable me to convert my avi files to use with ipad but I get the following error:
quote "Error converting to Apple Lossless, 'D:\Eigene Videos\Laila_2011_06_14_16-16_.AVI' to 'D:\Eigene Videos\Laila_2011_06_14_16-16_.m4a'
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