For #1506, refine the AAC samples guess algorithm.
For #1506, refine the AAC samples guess algorithm.

winlinvip/srs,winlinvip/srs,ossrs/srs,winlinvip/srs,ossrs/srs,ossrs/srs,winlinvip/srs,ossrs/srs,winlinvip/srs,ossrs/srs,winlinvip/simple-rtmp-server,winlinvip/srs,ossrs/srs