vf_format: support forwarding/stripping film grain metadata

DOCS/interface-changes.rst

@@ -40,6 +40,7 @@ Interface changes
       `--tone-mapping-desaturate-exponent`.
     - add `dolbyvision` sub-parameter to `format` video filter
     - `--sub-visibility` no longer has any effect on secondary subtitles
+    - add `film-grain` sub-parameter to `format` video filter
  --- mpv 0.34.0 ---
     - deprecate selecting by card number with `--drm-connector`, add
       `--drm-device` which can be used instead

DOCS/man/vf.rst

@@ -312,6 +312,10 @@ Available mpv-only filters are:
         Whether or not to include Dolby Vision metadata (default: yes). If
         disabled, any Dolby Vision metadata will be stripped from frames.
 
+    ``<film-grain=yes|no>``
+        Whether or not to include film grain metadata (default: yes). If
+        disabled, any film grain metadata will be stripped from frames.
+
     ``<stereo-in>``
         Set the stereo mode the video is assumed to be encoded in. Use
         ``--vf=format:stereo-in=help`` to list all available modes. Check with

video/filter/vf_format.c

@@ -58,6 +58,7 @@ struct vf_format_opts {
     int convert;
     int force_scaler;
     int dovi;
+    int film_grain;
 };
 
 static void set_params(struct vf_format_opts *p, struct mp_image_params *out,
@@ -156,6 +157,9 @@ static void vf_format_process(struct mp_filter *f)
         if (!priv->opts->dovi)
             av_buffer_unref(&img->dovi);
 
+        if (!priv->opts->film_grain)
+            av_buffer_unref(&img->film_grain);
+
 write_out:
         mp_pin_in_write(f->ppins[1], frame);
     }
@@ -215,6 +219,7 @@ static const m_option_t vf_opts_fields[] = {
     {"dar", OPT_DOUBLE(dar)},
     {"convert", OPT_FLAG(convert)},
     {"dolbyvision", OPT_FLAG(dovi)},
+    {"film-grain", OPT_FLAG(film_grain)},
     {"force-scaler", OPT_CHOICE(force_scaler,
                                 {"auto", MP_SWS_AUTO},
                                 {"sws", MP_SWS_SWS},
@@ -232,6 +237,7 @@ const struct mp_user_filter_entry vf_format = {
         .priv_defaults = &(const OPT_BASE_STRUCT){
             .rotate = -1,
             .dovi = 1,
+            .film_grain = 1,
         },
         .options = vf_opts_fields,
     },