sub: add SDH subtitle filter

Add subtitle filter to remove additions for deaf or hard-of-hearing
(SDH). This is for English, but may in part work for others too.
This is an ASS filter and the intention is that it can always be
enabled as it by default do not remove parts that may be normal text.
Harder filtering can be enabled with an additional option.

Signed-off-by: wm4 <wm4@nowhere>

2 files changed, 19 insertions, 0 deletions

diff --git a/DOCS/interface-changes.rst b/DOCS/interface-changes.rst
index 7bb6237042..253ea98a39 100644
--- a/DOCS/interface-changes.rst
+++ b/DOCS/interface-changes.rst
@@ -28,6 +28,8 @@ Interface changes
     - --af=drc is gone (you can use e.g. lavfi/acompressor instead)
     - remove image_size predefined uniform from OpenGL user shaders. Use
       input_size instead
+    - add --sub-filter-sdh
+    - add --sub-filter-sdh-harder
  --- mpv 0.24.0 ---
     - deprecate --hwdec-api and replace it with --opengl-hwdec-interop.
       The new option accepts both --hwdec values, as well as named backends.
diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index 96044760a1..02aaea2187 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -1991,6 +1991,23 @@ Subtitles
 
     Default: 0.
 
+``--sub-filter-sdh=<yes|no>``
+    Applies filter removing subtitle additions for the deaf or hard-of-hearing (SDH).
+    This is intended for English, but may in part work for other languages too.
+    The intention is that it can be always enabled so may not remove
+    all parts added.
+    It removes speaker labels (like MAN:), upper case text in parentheses and
+    any text in brackets.
+
+    Default: ``no``.
+
+``--sub-filter-sdh-harder=<yes|no>``
+    Do harder SDH filtering (if enabled by ``--sub-filter-sdh``).
+    Will also remove speaker labels and text within parentheses using both
+    lower and upper case letters.
+
+    Default: ``no``.
+
 Window
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