[FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs for autoscale/autorotate

[Fu, Linjie]

> -----Original Message-----
> From: Nicolas George [mailto:george at nsup.org]
> Sent: Thursday, July 18, 2019 03:07
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Cc: Fu, Linjie <linjie.fu at intel.com>
> Subject: Re: [FFmpeg-devel] [PATCH, v2 2/2] doc/ffmpeg.texi: update docs
> for autoscale/autorotate
> 
> Linjie Fu (12019-07-16):
> > Add docs for autoscale.
> >
> > Update information for autorotate according to ffplay.
> >
> > Signed-off-by: Linjie Fu <linjie.fu at intel.com>
> > ---
> >  doc/ffmpeg.texi | 14 ++++++++++----
> >  1 file changed, 10 insertions(+), 4 deletions(-)
> >
> > diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> > index cd35eb49c8..b91da2b2b4 100644
> > --- a/doc/ffmpeg.texi
> > +++ b/doc/ffmpeg.texi
> > @@ -734,10 +734,6 @@ ffmpeg -dump_attachment:t "" -i INPUT
> >  Technical note -- attachments are implemented as codec extradata, so this
> >  option can actually be used to extract extradata from any stream, not just
> >  attachments.
> > -
> > - at item -noautorotate
> > -Disable automatically rotating video based on file metadata.
> > -
> >  @end table
> >
> >  @section Video Options
> > @@ -819,6 +815,16 @@ Create the filtergraph specified by
> @var{filtergraph} and use it to
> >  filter the stream.
> >
> >  This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter
> option}.
> > +
> > + at item -autorotate
> > +Automatically rotate the video according to file metadata. Enabled by
> > +default, use @option{-noautorotate} to disable it.
> > +
> 
> > + at item -autoscale
> > +Automatically scale the video according to the resolution of first frame.
> > +Enabled by default, use @option{-noautoscale} to disable it. Each frame
> of
> > +the output raw video can be in different resolutions and is in need to be
> > +handled next.
> 
> Since this is completely hackish in lavfi, I think it needs to warn the
> user much more strongly to expect problems.

Yes, will update as Artie had suggested if no more comments:

When autoscale is disabled, all output frames might not be in the
same resolution and may require some additional explicit processing
according to your final rendering/output destination.