Use a larger input audio buffer, refill it when it has less than 4 KB data
left.
backport r23323 by mstorsjo
Originally committed as revision 23377 to svn://svn.ffmpeg.org/ffmpeg/branches/0.6
Passing an explicit filename to this command is only necessary if the
documentation in the @file block refers to a file different from the
one the block resides in.
Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
