[M4IF Technotes] Flexibility in resolution in Video levels

[Ben Waggoner]

Folks,
    I may be horribly confused about this, so bear with me.  Working with a
bunch of white papers instead of product can get rather confusing!
    When a video level defines a resolution, like Simple   Level 1 with QCIF,
how much flexibilty is there in distribution of the pixels?  176x144 has 99
16x16 blocks.  I gather you can redistribute those blocks to provide a
different aspect ratio, within some limits.  So, would a 256x96 would be
allowable if one wanted to stream Ben-Hur?  Is there any upper limit to
this?  Presumably 1584x16 wouldn't be a viable format for mobile devices.
    Also, was there any particular reason why non 4:3 resolutions were
chosen?  192x144 would be a lot more useful for normal content.  Is the
assumption that the 176x144 would be aspect ratio corrected to 4:3 on
playback?
Ben Waggoner
Interframe Media <http://www.interframemedia.com>
Digital Video Compression Consulting, Training, and Encoding