This tests sizes from 16 to 4096, not only the default 512.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

This moves some groups of tests for single codecs to separate files,
and adds shorthands for running all tests in a group.

Originally committed as revision 24697 to svn://svn.ffmpeg.org/ffmpeg/trunk