04-16-2009 01:59 PM
Playing encoded videos requires more bandwidth than just showing pictures.
Data into RAM -> Data + Previous frame out of RAM -> Frame into RAM -> Frame onto LCD
Maximum 30% of the memory bandwidth should be used for video. (Depending on the file format.)
X-res * Y-res * bpp/8 * fps = bytes per second.
MPEG4 uses much more processing power than MPEG2. MPEG4 decoding at 30 fps on a QVGA/CIF screen runs smoothly while MPEG2 can be run on VGA resolution.