[M4IF Technotes] Suggest some MPEG 4 Encoders

[Rob Koenen]

>     Dolby is a principle creator of AAC.  Apple may very well have
licensed
> it from them.  I don't know that there is a significant difference in AAC
> encoders from different vendors, like there used to be with MP3.

Dolby (according to Dolby and I assume also according to an independent
evaluation) is a license holder for AAC. Dolby is also a vendor of patent 
licenses (for Fraunhofer, AT&T, Dolby, Sony, Nokia) and Dolby often
ships technology to help getting you going. 
AAC is and MPEG standard. In the QT6 case, MPEG-4 AAC. There are many
different 
vendors of the technology. MPEG always standardizes the decoder and the
bistream
syntax, never the encoder. So there is a good chance that there are
differences
in quality between different encoders. THis is a deliberate strategy. It
makes
sure thre is interoperability, while there is also room for competition. 
Competition drives innovation. (MPEG-2 video encoders started out delivering
"broadcast quality" at 8 Mbit per second. Today, they use more like in the 
range of 2-3 Mbit on average in a statmux. The MPEG-2 decoder did not need
to
be upgraded fo this improvement in encoding quality.)
Best,
Rob