I've just bought a Samsung HMX10 that captures video footage directly for mp4 files with H264 codec. The problem is After Effects won't import any of the files recorded by this camera and gets the 'unsupported filetype or extension ( 0 :: 1 )' message. Premiere accepts the same files just fine. Is there a way to make After Effects use the same codecs as Premiere and/or some software to convert this files to some AE friendly format without losing much quality?
You can export your video from Premiere into any quicktime format, it should be handled by AE.
Or try to open your mp4 file into quicktime and save (file > save as) them as a mov file (you will need QT Pro). It won't affect the quality as it will only change the wrapper and not reencode the file.
As Sébastien said, convert or transcode it. Other alternatives to putting it into a QT container include for instance using tools like SUPER© to adjust the stream structure. Making AE use the same routines like premiere is not possible, but it wouldn't do much good, anyway, I would say. While Premiere can simply ignore things like open GOPs or other "bad stuff", AE can't, as it always needs to reconstruct a full frame for processing. Also be aware, that there is a million minor varaitions on the theme, as every camera manufacturer seems to have his on philosophy on teh matter, so some incompatibilities are sometimes inevitable. In your case however, these issues may already be covered in CS4, so if you have the time, consider giving it a spin and possibly upgrade to it. in the long run, it may be more efficient than always haveing to take a detour and the better integration with Premiere via Dynamic Link may also have additional benefits for you...