[FFmpeg-cvslog] doc/ffmpeg: document qscale and video stream special case

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sun Nov 17 16:00:47 2013 +0100| [74a8fe9483acbfd5dce34d2571a1d47e4dc654f3] | committer: Michael Niedermayer

doc/ffmpeg: document qscale and video stream special case

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=74a8fe9483acbfd5dce34d2571a1d47e4dc654f3
---

 doc/ffmpeg.texi |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 2bb65d5..af4cf9f 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -348,8 +348,13 @@ Stop writing to the stream after @var{framecount} frames.
 
 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
-Use fixed quality scale (VBR). The meaning of @var{q} is
+Use fixed quality scale (VBR). The meaning of @var{q}/@var{qscale} is
 codec-dependent.
+If @var{qscale} is used without a @var{stream_specifier} then it applies only
+to the video stream, this is to maintain compatibility with previous behavior
+and as specifying the same codec specific value to 2 different codecs that is
+audio and video generally is not what is intended when no stream_specifier is
+used.
 
 @anchor{filter_option}
 @item -filter[:@var{stream_specifier}] @var{filtergraph} (@emph{output,per-stream})