SUPPORTED FILE TYPES
.MP3
.OGG
.AAC
.ALAC
.AIF
.WAV

ugh..
thnx djmiyagi

no prob bro

.m4a are .mp4s according to en.wikipedia.org

aac and alac are the names for the audio formats you have in .m4a files.
chances are you can simply rename your .mp4 files to .m4a. afik it s the same.

but you'll only get audio...the point is for music vids.

I don't get it, the support page says the following

AAC
AAC is a more recent technology, intended as the successor to MP3. It is the default encoder in Apple iTunes and is part of the MPEG-4 specification. While AAC has many improvements over MP3, it is only now becoming adopted at the time of writing.

serato.com

If this is true then the program should be able to read mp4 (MPEG-4) files, as it cant it suggest that the only support if to MPEG2 ACC which uses the .AAC file extension.

Could someone explain if the documentation is incorrect or whether the program just does not support MPEG-4.

ALAC (Apple Lossless Audio Codec), this encoder use the file extension of .m4a NOT .ALAC

Can you specify is you are supporting certain Audio Formats or certain file extensions as the list you provided is confusing.

If you support the files encoded using ALAC then you must, by default, support files of extension m4a.
There is a comparison of container formats here, it does not list .ALAC
en.wikipedia.org

I have the Numark N4 and it does support mp4. It will not produce video output.

I have not fully tested yet but it seems to work fine.

Scratching does work.