Here\'s the mplayer output for a video of interest:
br@carina:/tmp$ mplayer foo.mov
mplayer: Symbol `ff_codec_bmp_tags\' has different size in shared object, co
You need to transcode your video in any case. Transcoding means you'll decode your stream, change framerate (drop frames in simple case) and then encode it again. Encoding configuration and even codec doesn't depend on how your video was encoded initially, so you can use anything suitable for your needs. If you need the highest possible quality, just encode with high profile as the first attempt. Then you can try to fine tune this even more playing with numerous h.264 encoding parameters.