I exported several files for a client....original files were 720P Quicktimes using ProRes. Converted in Carbon Coder using the H264 export to MP4. They play perfectly on PC's and Macs.
Today I took a client supplied Quicktime DV file compressed with DVCProNTSC. Converted it to H264/MP4 in Carbon Coder using the exact same preset. Changed the target file size to client requested 640x480 because client wants to play it back in a presentaion on their Mac. Everything else in the target settings are identical. Encodes fine. But when I try to open it in Quicktime on a PC or a Mac, it opens and plays the audio but there is no video, just a green screen where the video should be. If I play the same file in other players (KM_Player; MPlayer; VLC)...they all play the file fine.
Any guesses here. I repeated the test on another PC, same results. So it's not something system specific. I can use another codec but just can't figure out why it works on the one set of HD files but not the DV file.
Is there some limit I'm not aware of when resizing H264 files?