[Cin] Suggestion: improve presets for VP9 webm

Sun Sep 25 08:05:19 CEST 2022

вс, 25 сент. 2022 г., 08:25 Miroslav Rovis via Cin <
cin at lists.cinelerra-gg.org>:

> I changed the subject line: 's/setting/presets/'.
>
> On 220924-17:55-0600, Phyllis Smith wrote:
> > From my quick read, it sounds like a thorough analysis and
> > great suggestion.  I will have to read and look at all of this
> > more carefully so it can be updated accordingly.  And
> > hopefully, Andrew or Andrea will have time to comment too.
> > ...Phyllis
> I'm not an expert, but I am an advanced user. Unfortunately, a
> slow user too.  I'm probably correct (except for imprecise
> wordage) about this.
>
> Because (see below)...
>
> > On Sat, Sep 24, 2022 at 3:32 PM Miroslav Rovis via Cin <
> > cin at lists.cinelerra-gg.org> wrote:
> >
> > > It's simple, and my wording may not be quite precise, but
> > > you guys and gals will understand.
> > >
> > > So, when using the setting in the render window, I figured
> > > out that there are better settings to use than the presets
> > > that are offered. And they are simpler too.
>

settings live in ${cin_src_root}/ffmpeg/video

and yeah, no row-mt=1 there apart from av1 profile.
I only have asymmetric arm 8 core in tablet, and two 4 x86-64 cores in
desktop and laptop for testing....

> Because in this wiki page:
> > > In essence, the Wiki page for VP9 can tell you all:
> > > https://trac.ffmpeg.org/wiki/Encode/VP9 [*]
> previously there were recommendation on VP9 that correspond with
> the current presets in Cinelerra. The current version of VP9
> wiki page is, I believe, just a few months old.
>
> With the presets that I find in current Cinelerra; I'm yet to
> open it today and work with it, but I choose preset that are
> recommended for 1920x1080 30fps and then edit it as below.
> > > I have no rendering, actually no Cinelerra opened right now,
> > > so, from memory:
> > >
> > > It's just b=0, then add crf=31 (or other number), and then
> > > row-mt=1, and remove the min and max settings from the
> > > preset.
> > >
> > > I did use b=0 (which would correspond to -b 0 in the VP9
> > > wiki page (but I see only -b:v 0 in the page). And it did
> > > work I can tell you.
> > >
> > > However, see there around:
> > > "more contemporary CRF-style approach for the final pass to
> > > achieve a certain perceptual quality"
> > > and there is -b:v 0 in the second pass.
> > > and around:
> > > "must use a combination of -crf and -b:v 0. Note that -b:v
> > > MUST be 0."
> > >
> > > Also find:
> > > "FFmpeg added support for row based multithreading in
> > > version 3.4, released on January 25th, 2018. As of libvpx
> > > version 1.7.0 this multithreading enhancement is not enabled
> > > by default and needs be manually activated with the -row-mt
> > > 1 switch."
> > > which I find works great as well on my systems. They are
> > > relatively new:
> > > AMD Ryzen 7 PRO 4750G
> > > and also one:
> > > AMD Ryzen 7 5700G
> > > so if the above maybe would not work well on older machines,
> > > then, don't know...
> > >
> > > So, this is a suggestion to improve the VP9 webm presets in
> > > Cinelerra FFmpeg.
> > > While I am getting better at understanding the source code,
> > > I would still probably be to slow to find it and change it
> > > and send a patch myself. Too slow.
> > > And that would take me more time than I can set apart at
> > > this time.
> > >
> > > Regards!
> > >
> > > ---
> I have issues with motion plugin (or related to it). So I'll
> reuse this part below (which is missing a [*] at the start, as I
> meant the [*] above to refer to it) in a new, separate thread,
> not so much related to FFmpeg VP9 presets.
> > > I've been using VP9 (previously VP8) webm a lot. E.g.
> > > anywhere you go from:
> > > https://www.croatiafidelis.hr/2022/
> > > or, to take just one sample (4 minutes):
> > >
> > >
> https://www.croatiafidelis.hr/2022/Jazovka/VID-2022-06-22-1034-Jazovka-procesija.webm
> > > It's nothing but motion plugin set up, blur plugin in the
> > > bottom video at 100%, and go render. Then work the audio
> > > separately, mux and post. Of course, the stabilizing is
> > > slow, motion plugin takes long to calculate.
> > >
> > > But all those people moving can be scrutinized in a lot of
> > > detail, as if I filmed with a mobile phone attached to a
> > > good stabilizer, and instead, the original was a shaky video
> > > as ever, because I held the mobile with just my hand.
> > >
> > > Cinelerra can stabilize you videos well. It's worth the
> > > time-expensive learning curve to get to know how to do it.
> > >
> > > Here are some comparison videos with both the shaky and
> > > stabilized video (however I've gotten better since then,
> > > these are all old, but I have no other comparisons)
> > >
> > > e.g. from:
> > > https://www.croatiafidelis.hr/2019/
> > > the videos e.g.:
> > >
> > >
> https://www.croatiafidelis.hr/2019/Jaska/190824-Jaska-Vukovic-demo-1-stabilize.webm
> > > or from:
> > > https://www.croatiafidelis.hr/2015/Macelj/Macelj-2-cmp.php
> > > the video being:
> > >
> https://www.croatiafidelis.hr/2015/Macelj/150607-Macelj-HebrangCOMP.webm
> > >
> > > --
> > > Miroslav Rovis
> > > Zagreb, Croatia
> > > https://www.CroatiaFidelis.hr
> > > my PGP-key:
> > >
> https://www.croatiafidelis.hr/FCF13245ED247DCE443855B7EA9884884FBAF0AE.asc
> > > --
> > > Cin mailing list
> > > Cin at lists.cinelerra-gg.org
> > > https://lists.cinelerra-gg.org/mailman/listinfo/cin
> > >
>
> --
> Miroslav Rovis
> Zagreb, Croatia
> https://www.CroatiaFidelis.hr
> my PGP-key:
> https://www.croatiafidelis.hr/FCF13245ED247DCE443855B7EA9884884FBAF0AE.asc
> --
> Cin mailing list
> Cin at lists.cinelerra-gg.org
> https://lists.cinelerra-gg.org/mailman/listinfo/cin
>
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