Passing the return value to a subsequent av_adler32_update() call
allows the checksum of multiple buffers to be calculated as though
they were concatenated.
@param adler initial checksum value
@param buf pointer to input buffer
@param len size of input buffer
@return updated checksum
Calculate the Adler32 checksum of a buffer.
Passing the return value to a subsequent av_adler32_update() call allows the checksum of multiple buffers to be calculated as though they were concatenated.
@param adler initial checksum value @param buf pointer to input buffer @param len size of input buffer @return updated checksum