Struggling to get this working

[Simon Olley]

I downloaded ffmpegX yesterday and the project window opens ok. However when I drop a movie in (.mpg) all the target formats I've tried give me files that won't open. Some 'encode' immediately and the rendered file is 0kb, others take longer but all files get the warning that they could not be opened as they are not movie files. Any suggestions as to what might be the reason?

[Case]

I downloaded ffmpegX yesterday and the project window opens ok.

Installing the three binaries went smooth, then? Cool, because that seems to be quite a hurdle for some users.

However when I drop a movie in (.mpg) all the target formats I've tried give me files that won't open. Some 'encode' immediately and the rendered file is 0kb

That would be the sign of a failed conversion. It can happen for a number of reason, most of which can be solved. But the fix depends on the reason why it failed, and the fix can be different for different source files and target formats.
• Please supply the information on the source file that ffmpegX gives in the Summary, such as the video and audio details.
• Please supply the information on the target preset of your preferred conversion.
• Please supply a Process Information log. You may access that log by clicking the blue "i" in the ffmpegX Progress window, after a conversion attempt. This log should hold most clues to solving any issue with any particular conversion.

others take longer but all files get the warning that they could not be opened as they are not movie files. Any suggestions as to what might be the reason?

The "This file is not a movie file" error is a typical QuickTime error for any unsupported movie. It likely is a movie file, but QuickTime Player can't play it back.
For some formats this can be fixed by installing additional QuickTime Components, that aid the player in decoding (reading) the output movie file. One popular component is Perian, which will aid QuickTime in reading DivX/XviD AVI, MP4 and FLV, among others.
For some other formats, you should get a different player app, like VLC or MPlayerOSX.

We would like to help you out, but you have to help us help you, by giving more details on your source file and exactly what you are trying to do.