problem with convert to .mp4

[xioni]

i am trying to convert a set of .eps images to mpeg4 video file (i have made an animated gif successfully).

convert *.eps foo.mp4
convert -verbose -limit map 1gb -limit memory 1gb -density 300 -resize 33% -delay 8 *.eps foo.mp4

both appear to work and convert doesn't complain. a large file is produced (3x the sum of the sizes of the .eps files) with a .mp4 extension which won't play in quicktime or vlc or mpegstreamclip (on a intel mac running leopard). quicktime complains that it is not a movie file. mpegstreamclip claims it's an unsupported file type.

is there anything i should be aware of or something specific i should look at to determine what is the problem?
many thanks

[xioni]

though i still am unsure what is wrong i decided to go about this using a combination of convert and ffmpeg. i used convert to convert the .eps to .jpg images for the video. then i used ffmpeg to make the .mp4 files. only problem now is that i have 2 mpeg4 files that have different frame rates. i would love to put them together without reprocessing the two files. is this possible with 'convert' as it is with animated GIF?