Here's the familiar error:

**ERROR: [mplex] File /Volumes/externaldrive/Clip.ff.mpg unrecogniseable!

Here's the precise ffmpeg command that results in the file that mplex can't recognize (mplex can recognize and mux the source file, Clip.mpv):

/Applications/ffmpegX.app//Contents/Resources/ffmpeg -r 59.96 -i /Volumes/externaldrive/Clip.mpv -y -threads 2 -map 0.0:0.0 -target ntsc-dvd -b 9000 -aspect 16:9 -s 720x480 -r ntsc -g 32 -me epzs -qmin 1 -qmax 5 -an -benchmark /Volumes/externaldrive/Clip.ff.mpg

Here's the mplex command that generates the error:

/Applications/ffmpegX.app/Contents/Resources/mplex -f 3 -o /Volumes/externaldrive/Clip.mpg /Volumes/externaldrive/Clip.ff.mpg /Volumes/externaldrive/Clip.ac3

Changing the name extension of the input video file for the mplex command to ".mpv" doesn't help.

Can the ffmpeg command be modified to transcode a video elementary stream so that it can later be muxed using the mux button in the tools segment tab of ffmpegX? (I don't think ffmpegX can be used to transcode the original .mpv file because there doesn't seem to be a way to make ffmpegX distinguish between input and output frame rates. If there is, please tell me that, too!)

Thanks.