[Cin] The "Story of Dav1d" with Cinelerra builds (AV1 decoder)

[Andrew Randrianasulu]

В сообщении от Tuesday 03 September 2019 00:00:32 Phyllis Smith написал(а):
> As pointed out by Andrew (BT #214), using libdav1d as opposed to libaom for
> decoding (no encoding) is so attractive because it pretty much runs at full
> speed.  So when FFmpeg 4.2 included the compile option for this, we were
> highly motivated to put this in as the default for AV1 media
> loading/editing.  AV1 is yet another codec that seems to be newly relevant.
> 
> However as mentioned in a previous email, dav1d inclusion was a big problem
> for the older system monthly builds.  First, meson had to be at or above
> version 47 and only 5 out of 18 build systems were.  Consequently, GG ended
> up eliminating the "meson" requirement and substituting the standard "make"
> instead.  Then the "nasm" assembler on some of the older systems was not
> able to compile Dav1d so they had to be switched out for a newer/working
> version (11 out of 19 were OK).
> 
> If we had known the problems that would be encountered in applying
> libdav1d, I wonder if we would have included it at this time? 

Sorry, for not testing all those combination, I tend to just add/update new software
as some program ask for it. And being Slackware OS can be moved both ways (up/downgrade) equally easy.

I think obvious fix for nasm problem will be testing nasm version in cinelerra-5.1/configure.ac 
(like lines 464/465 currnetly do, but for something specific for 2.13 and up) and 
disable libdav1d with message if nasm too old.

nasm --version
NASM version 2.13.03 compiled on Mar 11 2018

Or may be compile nasm as part of Cin-GG build system, but I'm afraid this way will lead to Cin OS :}


> Also, as 
> mentioned in the BT #214, a remapping for decoding with libdav1d being the
> preference is in the {cinelerra_path}/ffmpeg/decode.opts file.  To revert
> to using libaom instead for decoding, you will need to comment out the
> line:   remap_video_decoder libaom-av1=libdav1d
> every time you update Cinelerra.  We have not tested what happens if there
> is either no libdav1d or libaom so if that creates a different problem, we
> will have to address that.   gg/Phyllis
> 
> *The following information is for the people who do their own builds.*
> 
> The easy workaround, if you do not care about AV1 files, is to add to the
> configure line in your script:
>    ./configure     ....     --disable-dav1d
> The better fix, is to upgrade nasm to at least 2.13 or higher.
> 
> Here is the list of the problem distro systems:
> 
> 
> *libdav1d requires minimum nasm>=2.13 && meson>=0.47   *
> *In the chart below * designates compile works, x designates compile fails*
> *meson           nasm            os      kernel*
> 0.51.2 *        2.14.02 *       arch    linux (5.2.9-arch1-1-ARCH)
> missing x       2.10.07 x       centos  3.10.0-957.10.1.el7.x86_64
> 0.21.0 x        2.11.05 x       debian8 3.16.0-10-amd64
> 0.37.1 x        2.12.01 x       debian9 4.9.0-9-amd64
> 0.37.1 x        2.12.01 x       debian9i 4.9.0-9-686-pae
> 0.49.2 *        2.14    *       debian10 4.19.0-5-amd64
> 0.47.2 *        2.13.03 *       fc28    5.0.16-100.fc28.x86_64
> 0.51.1 *        2.13.03 *       fc29    5.2.7-100.fc29.x86_644
> 0.50.1 *        2.13.03 *       fc30    5.2.9-200.fc30.x86_644
> missing x       2.13.03 *       su42.3  4.4.180-102-default
> 0.46.0 x        2.13.02 *       leap05  4.12.14-lp151.28.13-default
> 0.40.1 x        2.11.08 x       mint18  4.8.0-53-generic
> 0.45.1 x        2.13.02 *       mint19  4.15.0-20-generic
> missing x       2.10.09 x       ub14    3.13.0-170-generic
> 0.29.0 x        2.11.08 x       ub16    4.4.0-159-generic
> 0.45.1 x        2.13.02 *       4.15.0-58-generic
> missing x       2.10.09 x       ub14i   3.16.0-77-generic
> 0.46.1 x                *       slk32
> 0.46.1 x                *       slk34
> 
> *Summary:*
> meson   14 fail, 5 succeed
> nasm    8 fail, 11 succeed
> 
> To get a working set of builds for the month, the way gg used was to:
> 
> - generate a Makefile for x86 to replace meson (for now).
> - copy nasm "NASM version 2.13.03 compiled on Feb  2 2019" to:
>      debian8 debian9 debian9i leap03 ub16 ub14 ubuntu mint18
>