ffmpeg engine cropping error?

[brysongilbert]

when trying to encode .m2v to, well, anything, with the ffmpeg engine and trying to both scale and crop (which i've done a million times before with mencoder), i get this error in the log before it encodes anything:

Vertical crop dimensions are outside the range of the original image.
Remember to crop first and scale second.

so i try setting my crop values first, then determining what resolution i'll be scaling down to, but i still get the same error. any suggestions?

[csdesigns]

Make sure your targeted size value is divisible by 16. For instance, this message will appear if you try to crop and make a movie the size of 640x360. Yes, its a 16:9 ratio, but it won't work. If you need to crop, then you would have to size it to 624x352, both numbers of which are divisible evenly by 16.

[brysongilbert]

my final scaled image size was generated using the "auto" bitrate and image size calculator within ffmpegx, and is divisible by 16 in both dimensions: 688x288. my crop dimensions are also divisible by 16, at 720x368. the error persists. i don't get this error using mencoder, only with the ffmpeg engine, but i cannot encode this file with mencoder because i'm trying to retain 6-channel ac-3 audio, which mencoder always drops to 2-channel, regardless of my settings.

[major]

Are you entering the crop values in TBLR format required for ffmpeg (as opposed to WHXY mencoder format)?

[brysongilbert]

that's probably the problem.. i didn't realize there was a difference. i had used the autocrop in mencoder and just copied the values over. is there some quick math i can do to convert the values?

[major]

There is even a little app doing the maths.
http://www.versiontracker.com/dyn/moreinfo/macosx/24666

[brysongilbert]

you're the man, major. thanks again. works great.