vo_gpu_next: add new libplacebo-based renderer

As discussed in #8799, this will eventually replace vo_gpu. However, it
is not yet complete. Currently missing:

- OpenGL contexts
- hardware decoding
- blend-subtitles=video
- VOCTRL_SCREENSHOT

However, it's usable enough to cover most use cases, and as such is
enough to start getting in some crucial testing.

1 files changed, 12 insertions, 0 deletions

diff --git a/DOCS/man/vo.rst b/DOCS/man/vo.rst
index 7632f3c406..7897336266 100644
--- a/DOCS/man/vo.rst
+++ b/DOCS/man/vo.rst
@@ -257,6 +257,18 @@ Available video output drivers are:
     with ``rgb32f``. If you have problems, you can also try enabling the
     ``--gpu-dumb-mode=yes`` option.
 
+``gpu-next``
+    Experimental video renderer based on ``libplacebo``. This supports almost
+    the same set of features as ``--vo=gpu``. See `GPU renderer options`_ for a
+    list.
+
+    Currently, this only supports ``--gpu-api=vulkan``, and no hardware
+    decoding. Unlike ``--vo=gpu``, the FBO formats are not tunable, but you can
+    still set ``--gpu-dumb-mode=yes`` to forcibly disable their use.
+
+    Should generally be faster and higher quality, but some features may still
+    be missing or misbehave. Expect (and report!) bugs.
+
 ``sdl``
     SDL 2.0+ Render video output driver, depending on system with or without
     hardware acceleration. Should work on all platforms supported by SDL 2.0.