program freezes before file has converted, what can i do? I've got mac os lion, trying to convert video to mpeg, video is m4v

You are supplying way too little information:

what programs are you using, and how
what is the resolution of the source and destination films
what options have you selected for the conversion
what is the size in MB of the film
what kind of hardware are you using (CPU, RAM, HD)

Your question is the equivalent of going to a mechanic, saying to him : "My car doesn't run! without bringing the car with you. Would you expect the mechanic to be able to solve your problem then ?

Stating the problem fully and completely is the first order of business if/when you want to get any help.

yeah sorry: size of movie is: 891.3 MB , i selected export to mpeg-4.. the mpeg stream clip is version 1.9.3b7 and version I'm running is lion mac 10.7.2.. dimensions of film: 720 × 388 and codes H.264, AAC

hope what i gave you helps

i wanna convert an avi to mpeg4 to be played on a dvd player and will burn it in toast

conversion: MPEG streamclip 1.9.3b7; burning: Toast
still missing :: how you are using these programs
original video dimensions:720x388 ; target dimensions: ???
avi -> mpeg4, video:h.264, sound:AAC
original is 891.3 MB
still missing :: what kind of hardware are you using (CPU, RAM, HD)
10.7.2 Lion


MPEG streamclip is a bloody complex piece of software with a lot of options for you to really mess up with ! Squared 5 are explicitly stating, that 1.9.3b7 is a beta product that might be unstable.
I've no experience at all with Toast, but from the Squared 5 website, I gather that it want's mpeg2 ?!? -or- that Toast at least exports to mpeg2 when burning.
If your process is MPEG streamclip -> intermediate file -> Toast, you might be better off choosing AAIF (menu::File -> Export to Other Formats) as the format for the intermediate file. AAIF is using significant amounts of HD, but it's easier on the processor & time.

Now, I'm still missing the exact steps you've taken in your conversion process:

how are you opening the file
exactly which steps / menu selections did you choose when exporting / converting - if possible a screenshot if you are using one of the complex settings windows

In menu::List -> Log Window you can check the file for errors.

Qs:

Do you really need 1.9.3b7 or can you do with the stable 1.9.2 ?
Have you read the requirements section on the Squared 5 website, and have you installed all of the necessary components ??? This is one place where you can really screw up ;)
I'ld like to see the output from menu::File -> Show Stream Info for the original file.
can MPEG streamclip play the whole original file ?
can you play the whole original file in other players like QuickTime X, QuickTime 7, VLC, MPlayerX ?
are you able to convert to other formats, or does MPEG streamclip freeze under all circumstances ?
are you able to convert from other input formats, or does MPEG stramclip freeze for these also ?
how far does the conversion process come before it freezes ?
When MPEG streamclip freezes, what does Activity Monitor show about the process ?
I'ld like to see the output in the log window from the conversion process.