Log Message:
Update multimedia/mpv to 0.26.0

pkgsrc changes:
 - Adjust SUBST `audio' class after recent ao_oss changes
 - Backport a patch to fix issue #4642 (`ao_oss: fix a dumb calculation').

Changes:
Release 0.26.0
==============
VA-API/VDPAU hardware decoding now requires FFmpeg > 3.2.
DVB support is disabled by default since it does not work with some older kernels.
Built-in V4L TV support is disabled by default. av://v4l2 can be used instead.
Support for C plugins is now enabled by default (#4491).

Many more parts of the player are now licensed under LGPL, see Copyright file.
Thanks to all contributors who have agreed to relicensing of their changes!
See #2033 for details.

Features
--------
Added
~~~~~
- Universal Windows Plaform (UWP) support (libmpv only)
- csputils: implement sony s-gamut
- js: add javascript scripting support using MuJS
  See DOCS/man/javascript.rst for more details
- vo_opengl: add new HDR tone mapping algorithm (mobius, now default)
- vo_opengl: hwdec_cuda: Support separate decode and display devices
- vo_opengl: implement sony s-log1 and s-log2 trc
- vo_opengl: implement support for OOTFs and non-display referred content

Removed
~~~~~~~
- vf_dlopen: remove this filter

Options and Commands
--------------------
Added
~~~~~
- vo_opengl: add --tone-mapping-desaturate
- vo_opengl: support tone-mapping-param for `clip`
- ytdl_hook: add option to exclude URLs from being parsed

Changed
~~~~~~~
- allow setting profile option with libmpv
- audio: move replaygain control to top-level options
- external_files: parse ~ in --{sub,audio}-paths
- options: change --sub-fix-timing default to no (#4484)
- options: expose string list actions for --sub-file option
- options: slight cleanup of --sub-ass-style-override
  * signfs → scale
  * --sub-ass-style-override → --sub-ass-override
- renamed the HDR TRCs `st2084` and `std-b67` to `pq` and `hlg` respectively
- replace vf_format's `peak` suboption by `sig-peak`, which is relative to the \ 
reference white level instead of in cd/m^2
- the following options change to append-by-default (and possibly separator):
  * --script
- video: change --video-aspect-method default value to `container`

Deprecated
~~~~~~~~~~
- m_option: deprecate multiple items for -add etc.
- player: deprecate "osd" command
- --audio-file-paths => --audio-file-path
- --sub-paths => --sub-file-path
- --opengl-shaders => --opengl-shader
- --sub-paths => --sub-file-paths
- the following options are deprecated for setting via API:
  * "script" (use "scripts")
  * "sub-file" (use "sub-files")
  * "audio-file" (use "audio-files")
  * "external-file" (use "external-files")
  (the compatibility hacks for this will be removed after this release)

Removed
~~~~~~~
- chmap: remove misleading "downmix" channel layout name (#4545)
- demux_lavf: remove --demuxer-lavf-cryptokey option (#4579)
- input.conf: drop TV/DVB bindings
- options: remove remaining deprecated audio device selection options
  * --alsa-device
  * --oss-device
  * --coreaudio-exclusive
  * --pulse-sink
  * --rsound-host/--rsound-port
  * --ao-sndio-device
  * --ao-wasapi-exclusive
  * --ao-wasapi-device
- remove option --target-brightness
- remove property "video-params/nom-peak"

Fixes and Minor Enhancements
----------------------------
- TOOLS/lua/autoload.lua: actually sort files case insensitive (#4398)
- TOOLS/lua/autoload.lua: ignores all files starting with "."
- ao_openal: kill off device listing (#4311)
- ao_pulse: reorder format choice to prefer float and S32 over S16 as fallback format
- ao_wasapi: try correct initial format (#4582)
- command: add missing change notification for playlist-shuffle (#4573)
- demux_disc: fix bluray subtitle language retrieval (#4611)
- demux_mkv: fix alpha with vp9 + libvpx
- demux_mkv: support FFmpeg A_MS/ACM extensions
- ipc-unix: don’t truncate the message on EAGAIN (#4452)
- ipc: raise json nesting limit (#4394)
- macOS: fix mpv-wrapper.sh when used with csh or tcsh shell
- macOS: properly unhide Dock when quitting during System fs animation
- mpv_identify: replace deprecated fps property (#4550)
- options/path: fallback to USERPROFILE if HOME isn't set
- player: close audio device on no audio track
- player: fix potential segfault when playing dvd:// with DVD disabled (#4393)
- player: prevent seek position to jump around adjacent keyframes, e.g. when \ 
dragging the OSC bar on short videos (#4183)
- vo_opengl: bump up SHADER_MAX_HOOKS and MAX_TEXTURE_HOOKS to 64
- vo_opengl: correct off-by-one in scale=oversample
- vo_opengl: do not use vaapi-over-GLX (#4555)
- vo_opengl: fall back to ordered dither instead of blowing up (#4519)
- vo_opengl: tone map in linear XYZ instead of RGB
- x11: add 128x128 sized icon support
- ytdl_hook: add a header to support geo-bypass
- ytdl_hook: don't override start time set by saved state
- ytdl_hook: don't override user-set start time
- ytdl_hook: treat single-entry playlists as a single video