This allows UDP receive buffer size to be increased to avoid potential
packet loss result from receive buffer overrun.
Another related flag is --io_cache_size. buffer_size in UDP options
defines the UDP buffer size of the underlying system while
io_cache_size defines the size of the internal circular buffer managed
by Shaka Packager.
Closes#411
Change-Id: I57c843a88f13da546417dadc2a78df2bee0a00f3
It aligns with what a lot of other apps are doing, e.g. tsplay.
Also added notes in docker to adjust network setting if wants to use
multicast in docker container.
Change-Id: I666a8979cc041c904f7ff8e3e022f800c0830d5d
KongQun Yang
fatpelt