[M4IF Technotes] RE: [M4IF Infolist] A question about Simple profile and mobile pr ofile

[Rob Koenen]

Dear Lei Ming,
(taking your question to the technotes list)
> How many levels are defined for Simple profile and Mobile 
> profile? 

Simple: 0-3 (= 4 lelvels, 0 was added later below 1)
Main: 3 Levels, upt o 38 Mbit/s
> What are the differences between
> the levels? 
> Whether tools make any difference or only image size?

Parameters like image surface (usually not size, you
can determine the aspect ratio yourself), amount of objects,
bitrate, reference buffer sizes, framerate.
Tools usually do NOT change across levels for a certain profiles,
but there are a few exceptions (e.g. interlace support in Advanced SImple
only starting from Level 4.
BEst,
Rob