[FFmpeg-cvslog] doc/ffmpeg: clarify behaviour of -discard

[Gyan Doshi]

ffmpeg | branch: master | Gyan Doshi <ffmpeg at gyani.pro> | Fri Jan  4 16:05:33 2019 +0530| [1087b792c37630466716c3544539c583c14489a9] | committer: Gyan Doshi

doc/ffmpeg: clarify behaviour of -discard

Discarding all frames is universally supported as it happens in fftools
whereas selective discarding relies on the demuxer.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1087b792c37630466716c3544539c583c14489a9
---

 doc/ffmpeg.texi | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 3687ab0d5c..8a36a9699d 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -1640,8 +1640,10 @@ This allows dumping sdp information when at least one output isn't an
 rtp stream. (Requires at least one of the output formats to be rtp).
 
 @item -discard (@emph{input})
-Allows discarding specific streams or frames of streams at the demuxer.
-Not all demuxers support this.
+Allows discarding specific streams or frames from streams.
+Any input stream can be fully discarded, using value @code{all} whereas
+selective discarding of frames from a stream occurs at the demuxer
+and is not supported by all demuxers.
 
 @table @option
 @item none