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jbillo / xenonmkv

MKV to MP4 container conversion tool with minimal re-encoding
http://xenonmkv.ev98.net/
GNU General Public License v2.0
19 stars 8 forks source link

Apple profile #11

Open brianfroelund opened 11 years ago

brianfroelund commented 11 years ago

Hi. Thanks for a great piece of software :)

I'm trying to remux for an apple tv. The only problem is that i can't get the sound working.

I found a thread on apple forums saying that the aac sound track should be of type 64 (0x40) instead of 103 (0x67).

I tried changing the value in a .mp4 already processed by xenonmkv in an editor for windows and it does fix the sound.

My idea was to implement an apple profile for xenonmkv but i can't figure out how to fix this problem using the tools that xenonmkv uses (or any other linux software for that matter).

I've tried faac -mpeg 4 option which does make the sound work on apple devices. It does however also cause the sound to be way of sync ( a good 2 minutes ).

I'm not expecting you to implement a solution for my problem but i'm getting to the point now where i could really use some input from one who has a better understanding of how this all works.

Thanks in advance. - Brian

jbillo commented 11 years ago

Hi Brian,

Thanks for the details. Unfortunately I'm not a complete expert on the AAC file format and have no idea if the 'type' byte is always at a certain offset or position (this is how I change the H.264 video profile level to 4.1). If this were the case it would be an easy implementation.

Do you know of other software that is able to accomplish this change?

brianfroelund commented 11 years ago

MP4Box is able to show it using the -info command (Look for 0x67 after it's been processed by xenonmkv). Pretty sure it's not able to change it though.

The windows tool i used is called: http://mp4ui.sourceforge.net/ it's quite old :)

But maybe just looking at the MP4Box source seeing how they read it will make me understand how to change it :)