[FFmpeg-devel] [PATCH v2 3/6] doc: update for libsvtav1 encoder

[lance.lmwang at gmail.com]

On Sat, Sep 25, 2021 at 02:32:43PM +0300, Jan Ekström wrote:
> On Sat, Sep 18, 2021 at 4:27 AM <lance.lmwang at gmail.com> wrote:
> >
> > From: Limin Wang <lance.lmwang at gmail.com>
> >
> > Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> > ---
> 
> Hi,
> 
> "doc/encoders: add available values for libsvtav1 options"
> 
> would possibly be better as a commit message?

Sure, I'll change that.

> 
> >  doc/encoders.texi | 44 ++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 44 insertions(+)
> >
> > diff --git a/doc/encoders.texi b/doc/encoders.texi
> > index 8fccd73..64d604e 100644
> > --- a/doc/encoders.texi
> > +++ b/doc/encoders.texi
> > @@ -1750,12 +1750,56 @@ You need to explicitly configure the build with @code{--enable-libsvtav1}.
> >  @table @option
> >  @item profile
> >  Set the encoding profile.
> > + at table @samp
> > + at item main
> > + at item high
> > + at item professional
> > + at end table
> >
> >  @item level
> >  Set the operating point level.
> > + at table @samp
> > + at item 2.0
> > + at item 2.1
> > + at item 2.2
> > + at item 2.3
> > + at item 3.0
> > + at item 3.1
> > + at item 3.2
> > + at item 3.3
> > + at item 4.0
> > + at item 4.1
> > + at item 4.2
> > + at item 4.3
> > + at item 5.0
> > + at item 5.1
> > + at item 5.2
> > + at item 5.3
> > + at item 6.0
> > + at item 6.1
> > + at item 6.2
> > + at item 6.3
> > + at item 7.0
> > + at item 7.1
> > + at item 7.2
> > + at item 7.3
> > + at end table
> > +
> 
> The levels list is somewhat long, and it's specific to AV1 and not
> this encoder. I don't think we list H.264/HEVC etc levels, either?
> 
> So I'm not 100% sure on this bit, possibly just noting "Set the
> operating point level, f.ex. '4.0'." is good enough?

Yes, I think it's too long also. I can update by your idea.

> 
> > + at item hielevel
> > +Set the Hierarchical prediction levels.
> > + at table @samp
> > + at item 3level
> > + at item 4level, This is the default.
> 
> You probably mean this to be on a separate line. Right now it ends up
> as part of the entry on the list a la: ‘4level, This is the default.’
> 
> Noticed through the HTML documentation output (ffmpeg-codecs.html).

OK, will change that

> 
> > + at end table
> >
> >  @item tier
> >  Set the operating point tier.
> > + at table @samp
> > + at item main
> > +The main tier was designed for most applications. This is the default.
> > + at item high
> > +The high tier was designed for very demanding applications.
> > + at end table
> >
> 
> Looking at https://aomediacodec.github.io/av1-spec/av1-spec.pdf , it
> seems like the high tier only enable higher bit rates/lower
> compression ratios in levels.
> 
> I think explaining it like that is probably more understandable than
> vague references for "most applications" and "very demanding
> applications". Or only explaining which one is the default, as I would
> expect a person who needs to set this flag to know what the tier flags
> in AV1 bit stream mean.

OK, will only explaining which one is the default.

> 
> Jan
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".

-- 
Thanks,
Limin Wang