[Cin] Suggestion: improve setting for VP9 webm

Phyllis Smith phylsmith2017 at gmail.com
Mon Sep 26 22:14:35 CEST 2022

Your ivp9 webm improvements/simplifications look good to me.  After running
some tests, I have checked into GIT a new vp9.webm with only the 3 lines of
b=0, crf=31, row-mt=1.  From Andrea's tests, it seems like the other option
lines are maybe not needed.  I ran with and without them and I only saw a
small size difference in the resulting file and could not visually see any
difference.  As far as speed goes, I just got varying results and for me it
is slow like Andrea report and since I only do testing, I have the need for

Also, I made the default for new configurations/users to be "vp9.webm"
instead of "webm.webm".

(Plus deleted old library versions of libvpx 1.11.0 and libaom 3.2.0 and
their associated patches.)

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.
> In essence, the Wiki page for VP9 can tell you all:
> https://trac.ffmpeg.org/wiki/Encode/VP9 [*]
> 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'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
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