Merge commit 'c94e2e85cb6af8a570d8542a830556243bd32873'

* commit 'c94e2e85cb6af8a570d8542a830556243bd32873':
  nut: Support experimental NUT 4 features

Conflicts:
	doc/nut.texi
	libavformat/nut.h
	libavformat/nutdec.c
	libavformat/nutenc.c

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

2 files changed, 38 insertions, 0 deletions

diff --git a/doc/muxers.texi b/doc/muxers.texi
index bab0081724..c1cf18607b 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -706,6 +706,23 @@ Alternatively you can write the command as:
 ffmpeg -benchmark -i INPUT -f null -
 @end example
 
+@section nut
+
+@table @option
+@item -syncpoints @var{flags}
+Change the syncpoint usage in nut:
+@table @option
+@item @var{default} use the normal low-overhead seeking aids.
+@item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;
+@item @var{timestamped} extend the syncpoint with a wallclock field.
+@end table
+The @var{none} and @var{timestamped} flags are experimental.
+@end table
+
+@example
+ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
+@end example
+
 @section ogg
 
 Ogg container muxer.
diff --git a/doc/nut.texi b/doc/nut.texi
index 0026a121b5..fee12da9e7 100644
--- a/doc/nut.texi
+++ b/doc/nut.texi
@@ -21,6 +21,27 @@ The official nut specification is at svn://svn.mplayerhq.hu/nut
 In case of any differences between this text and the official specification,
 the official specification shall prevail.
 
+@chapter Modes
+NUT has some variants signaled by using the flags field in its main header.
+
+@multitable @columnfractions .4 .4
+@item BROADCAST   @tab Extend the syncpoint to report the sender wallclock
+@item PIPE        @tab Omit completely the syncpoint
+@end multitable
+
+@section BROADCAST
+
+The BROADCAST variant provides a secondary time reference to facilitate
+detecting endpoint latency and network delays.
+It assumes all the endpoint clocks are syncronized.
+To be used in real-time scenarios.
+
+@section PIPE
+
+The PIPE variant assumes NUT is used as non-seekable intermediate container,
+by not using syncpoint removes unneeded overhead and reduces the overall
+memory usage.
+
 @chapter Container-specific codec tags
 
 @section Generic raw YUVA formats