How to join/merge MP4's (H264) with AVIdemux

[czgirb]

Currently I'm using Ubuntu 12.04.
How to join/merge MP4's (H264) into One file by using AVIdemux?
Please guide me ...
Thank you

Notes:
Generally, I joined my AVI file by using AVIdemux with Open => Append => Save.
But with H264, it won't ...

[Baldrick]

Yes, it's correct.

What happens? Any errors?
Are you using latest avidmeux 2.6?

[czgirb]

AVIdmeux 2.6 ... yes. it should be
AVIdemux said ... the map is unable to be build due to H264

[czgirb]

SORRY! My AVIdemux is installed 4-day ago and it was 2.5.4 version

When I opened the file, it said:

H.264 detected
If the file is using B-frames as reference it can lead to a crash or stuttering.
Avidemux can use another mode which is safe but YOU WILL LOSE FRAME ACCURACY.
Do you want to use that mode?

When I press USE SAFE MODE, besides the UI's size changed to be bigger ... nothing's happen
Is there something wrong with my AVIdemux?
Please guide me ..............

[Baldrick]

Try find avidemux 2.6. It's MUCH better with h264 video.

[bat999]

Try find avidemux 2.6. It's MUCH better with h264 video.

Avidemux-2.6 isn't available in Ubuntu's repos. ---> http://packages.ubuntu.com/search?searchon=names&keywords=avidemux

Would need to compile it.

Or try with GetDeb ---> http://www.getdeb.net/software/Avidemux%202.6