Timestamp Correction Algorithm: Mixed Incremental Algorithm, mix_correct, to ensure the timestamp monotonically increases.

[Winlin]

https://github.com/winlinvip/simple-rtmp-server/issues/383

TRANS_BY_GPT3

[Winlin]

See

        # whether use the interleaved/mixed algorithm to correct the timestamp.
        # if on, always ensure the timestamp of audio+video is interleaved/mixed monotonically increase.
        # if off, use time_jitter to correct the timestamp if required.
        # @remark to use mix_correct, atc should on(or time_jitter should off).
        # default: off
        mix_correct             off;