vf_format: add dolbyvision sub-option

Useful to strip dolbyvision from the output, in cases where the user
does not want it applied. Doing this as a video filter gives users the
abiilty to easily toggle this stripping at runtime in a way that
properly propagates to any (potentially stateful) VO.

It also thematically fits the rest of the options in vf_format, which
are similarly concerned with modifying the video image parameters.

DOCS/interface-changes.rst

@@ -38,6 +38,7 @@ Interface changes
     - add `--gamut-mapping-mode`, replacing `--gamut-clipping` and `--gamut-warning`
     - add `--tone-mapping-mode`, replacing `--tone-mapping-desaturate` and
       `--tone-mapping-desaturate-exponent`.
+    - add `dolbyvision` 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

@@ -308,6 +308,10 @@ Available mpv-only filters are:
        :709-1886:     Scene-referred using the BT709+BT1886 interaction
        :gamma1.2:     Scene-referred using a pure power OOTF (gamma=1.2)
 
+    ``<dolbyvision=yes|no>``
+        Whether or not to include Dolby Vision metadata (default: yes). If
+        disabled, any Dolby Vision 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

@@ -22,6 +22,7 @@
 #include <math.h>
 
 #include <libavutil/rational.h>
+#include <libavutil/buffer.h>
 
 #include "common/msg.h"
 #include "common/common.h"
@@ -56,6 +57,7 @@ struct vf_format_opts {
     double dar;
     int convert;
     int force_scaler;
+    int dovi;
 };
 
 static void set_params(struct vf_format_opts *p, struct mp_image_params *out,
@@ -141,14 +143,16 @@ static void vf_format_process(struct mp_filter *f)
 
     if (mp_pin_can_transfer_data(f->ppins[1], priv->conv->f->pins[1])) {
         struct mp_frame frame = mp_pin_out_read(priv->conv->f->pins[1]);
+        struct mp_image *img = frame.data;
 
         if (!priv->opts->convert && frame.type == MP_FRAME_VIDEO) {
-            struct mp_image *img = frame.data;
-
             set_params(priv->opts, &img->params, false);
             mp_image_params_guess_csp(&img->params);
         }
 
+        if (!priv->opts->dovi)
+            av_buffer_unref(&img->dovi);
+
         mp_pin_in_write(f->ppins[1], frame);
     }
 }
@@ -206,6 +210,7 @@ static const m_option_t vf_opts_fields[] = {
     {"dh", OPT_INT(dh)},
     {"dar", OPT_DOUBLE(dar)},
     {"convert", OPT_FLAG(convert)},
+    {"dolbyvision", OPT_FLAG(dovi)},
     {"force-scaler", OPT_CHOICE(force_scaler,
                                 {"auto", MP_SWS_AUTO},
                                 {"sws", MP_SWS_SWS},
@@ -222,6 +227,7 @@ const struct mp_user_filter_entry vf_format = {
         .priv_size = sizeof(OPT_BASE_STRUCT),
         .priv_defaults = &(const OPT_BASE_STRUCT){
             .rotate = -1,
+            .dovi = 1,
         },
         .options = vf_opts_fields,
     },