rtmpproto: Check the buffer sizes when copying app/playpath strings

As pointed out by Reimar Döffinger.

CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
Merge commit '0bacfa8d37710b904897e7cbeb8d6f96fbf75e2e'

* commit '0bacfa8d37710b904897e7cbeb8d6f96fbf75e2e':
  rtmpproto: Check the buffer sizes when copying app/playpath strings

Conflicts:
	libavformat/rtmpproto.c

See: 0c2a6dabced53b4df57aedf47f0c1b8233035fed
See: 02ac3398eb52679301028c2fd3ebad1b6261b4da
Merged-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/phase: add comment on the context cached frame.
avfilter/phase: do not pass the whole context to analyze_plane().

Also make sure the AVFilterContext is only being used for logging by
changing the type to void*
avfilter/phase: avoid a memcpy per frame.
avfilter/phase: add timeline support.
avfilter/phase: add some constness for RO data pointers.
avfilter/phase: make the main loop readable.
hvcodec/x86/hevcdsp: make macros more modular to support functions that are not sse4

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>