[Mp4-tech] Sample MP4 file

[Hans-Juergen Bardenhagen]

Hi Shailendra,
on 26.02.04, 16:18 local time (received 26.02.04, 18:48 GMT+1) you wrote:
> The context for this question is that I came across a couple of files
> with .mp4 extension containing audio and video data which were
>     - played by QuickTime Player (Version 6.5), both audio and video
>     - played by DivX Player 2.5.2 but video only (I see a warning
> which says "This file contains unknown audio data" and further
> complains about "Audio data :  Tag 5376")

The DivX Player does not know AAC, only MP3 (d'oh!), but this is  
standard-compliant, so it can call itself a "MPEG-4 Player". Same is  
true for the currently available DVD players with that lable, they all  
don't know AAC audio, only MP3 combined with MPEG-4 video within an AVI  
container (double d'oh!) ;-)
>     - rejected by Windows Media player (latest version, version 9),
> warning about unrecognized file extension

WMP doesn't know anything about MP4 by itself, you have to install a  
DirectShow filter or a plugin for it, e.g. 3ivx, mpegable, LSX-MPEG  
Player or EnvivioTV.
>     -  attempted to play by Real Player but RealPlayer fails
> (searches for a software update to enable playing this .mp4 file but
> fails to find one)

Until now the free RealPlayer doesn't know the MP4 container either, but  
it is rumoured that the commercial "Gold" edition will have this feature  
which should be released soon.
> (3) I also recently heard that RealPlayer does not play MP4 file with
> hint tracks, MP4 files without hint tracks are decodable. Is this
> correct ?

Hmm, don't know about that issue, sorry. Maybe this refers to the open  
source Helix Server application by RealNetworks... By the way, I created  
a short table with available freeware MPEG-4 players for Windows in the  
Wiki of Audiocoding.com recently, maybe this is of some help for you:
http://www.audiocoding.com/wiki/index.php?page=MPEG-4+players
ZZee ya, Hans-Jürgen