I had no problem at all to import any MP4 file to AE CS4(even the file i download it from youtube as mp4 format, work just fine )untill I updated QuickTime Pro from 7.5.xx to 7.62.14 .I wonder if it is because the different quicktime version ’cause this problem
the reason i had to updated QuickTime Pro is that after my windows vista auto updated, my Quicktime Pro 7.5 had problem to quit when i tried to close it (playback is fine), it kinda bother me ,so i updated my QuickTime to 7.62.14 and it playback fine too, however, I no longer able to import my mp4 to AE after updated, neither to import to Adobe media encoder.
so for me, i don’t think MP4 can’t not be import to AE at first place untill now I had same problem. any suggestion ?