#207 Implicit SBR detection via AudioSpecificConfig fails when char is unsigned

[Fabian Greffrath]

Hi Krzysztof,

this bug has been reported against the faad2 package in Debian.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=843173

In short, the sbr_present_flag member in struct mp4AudioSpecificConfig is declared as a char and gets initialized to -1 in AudioSpecificConfigFromBitfile(). However, on systems with unsigned char the latter comparison of its value with -1 fails. The attached patch fixes this without changing the ABI, but leaves the correct change for the initialized value to the API user.

Thanks,

Fabian

[Fabian Greffrath]

Applied in Debian, thanks!