VirtualDub and MP4

[PeteRooney]

Good afternoon,
Probably a daft newbie question, but is there any way in which I can get VirtualDub to work with MP4 format?
I have a number of pairs of MP4s that need to be merged into single files, but I'm having to convert them into AVI format with MediaCoder (which, incidentally is currently losing the audio in the finished AVIs at the moment, so any help on THAT would be appreciated, too!) before I can use VirtualDub to merge them. It would make life a lot easier if i could simpley append the MP4s in VirtualDub.
All advice gratefully received!
Thanks in advance for your help.

[Placio74]

Use Yamb (MP4Box) or Avidemux to join MP4 files.

[LoRd_MuldeR]

VirtualDub doesn't support the MP4 container, so you'll need a different tool. Try the ones suggested by Placio74.

[PeteRooney]

Thanks to both of you for your advice.
I'm currently using AimerSoft's video converter to merge the files using "Archos AVI" as my output format, but I'm not sure if it's outputting a true AVI or simply an MP4 with an AVI file extension.
Is there any way I can look at the output merged files to see what it's really produced?

[setarip_old]

Hi!

Load it into GSpot and post a screen capture back here...

[Placio74]

...
I'm currently using AimerSoft's video converter to merge the files using "Archos AVI" as my output format, but I'm not sure if it's outputting a true AVI or simply an MP4 with an AVI file extension. ...
It merge and re-encode A/V. Also resize and change FPS.

Used Yamb (MP4Box) or Avidemux can join MP4's without re-encoding.

...Is there any way I can look at the output merged files to see what it's really produced?
Use GSpot or MediaInfo.

BTW
VirtualDub with QuickTime input plugin can open MP4 files, but can't save to MP4 (only AVI).