Madbullram
I have used MKVToolnix for re-muxing. I extracted AAC from MP4 file using another tool called OJOSoft converter and converted to AC3.
I used MKVToolnix to mux MP4 video (AVC1) and AC3 and generated a MKV file. So far so good. When i played the file, my AVR recognized the audio as Doby Digital and reproduced the sound. However, there seem to be a sound lag (no synch between Video and Audio). There seem to be no issue when i play with VLC on my comp, but WDTV seem to be having the lag issue.
I tried setting the "Delay (in ms)" and "Stretch by" fields in MKVToolNix (MKV Merge), but no luck. Any pointers to what could be the issue and what settings should i use for Lag and Stretch fields.
Thanks
Zorro
Woah , just saw this post ! Please refer to my above post for jhamela free experience. The only downside is that the container changes from mp4 to mkv but that really is not a problem . I have reencoded 6-7 movies till date , no lag whatsoever.