command: add vf-metadata property

This is a read-only property that uses VFCTRL_GET_METADATA
to retrieve mp_tags metadata from a filter specified by label

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

2 files changed, 49 insertions, 2 deletions

diff --git a/DOCS/man/en/input.rst b/DOCS/man/en/input.rst
index f6a0f04833..d6e3affcad 100644
--- a/DOCS/man/en/input.rst
+++ b/DOCS/man/en/input.rst
@@ -731,7 +731,7 @@ Property list
             (key and string value for each metdata entry)
 
 ``chapter-metadata``
-    Metadata of current chapter. Works similar to ``metadata`` property. IT
+    Metadata of current chapter. Works similar to ``metadata`` property. It
     also allows the same access methods (using sub-properties).
 
     Per-chapter metadata is very rare. Usually, only the chapter name
@@ -740,6 +740,17 @@ Property list
     For accessing other information, like chapter start, see the
     ``chapter-list`` property.
 
+``vf-metadata/<filter-label>``
+    Metadata added by video filters. Accessed by the filter label,
+    which if not explicitly specified using the ``@filter-label:`` syntax,
+    will be ``<filter-name>NN``.
+
+    Works similar to ``metadata`` property. It allows the same access
+    methods (using sub-properties).
+
+    An example of these kind of metadata are the cropping parameters
+    added by ``--vf=lavfi=cropdetect``.
+
 ``pause`` (RW)
     Pause status. This is usually ``yes`` or ``no``. See ``--pause``.
 
diff --git a/player/command.c b/player/command.c
index 8891fdd3f3..cc4cc0892a 100644
--- a/player/command.c
+++ b/player/command.c
@@ -617,7 +617,6 @@ static int mp_property_edition(m_option_t *prop, int action, void *arg,
     return M_PROPERTY_NOT_IMPLEMENTED;
 }
 
-
 static int get_edition_entry(int item, int action, void *arg, void *ctx)
 {
     struct MPContext *mpctx = ctx;
@@ -933,6 +932,42 @@ static int mp_property_chapter_metadata(m_option_t *prop, int action, void *arg,
     return tag_property(prop, action, arg, demuxer->chapters[chapter].metadata);
 }
 
+static int mp_property_vf_metadata(m_option_t *prop, int action, void *arg,
+                                   MPContext *mpctx)
+{
+    if (!(mpctx->d_video && mpctx->d_video->vfilter))
+        return M_PROPERTY_UNAVAILABLE;
+    struct vf_chain *vf = mpctx->d_video->vfilter;
+
+    switch(action) {
+    case M_PROPERTY_GET_TYPE:
+    case M_PROPERTY_GET:
+    case M_PROPERTY_GET_NODE:
+        return M_PROPERTY_NOT_IMPLEMENTED;
+    case M_PROPERTY_KEY_ACTION: {
+        struct m_property_action_arg *ka = arg;
+        bstr key;
+        char *rem;
+        m_property_split_path(ka->key, &key, &rem);
+        struct mp_tags vf_metadata;
+        if (vf_control_by_label(vf, VFCTRL_GET_METADATA, &vf_metadata, key)
+                == CONTROL_UNKNOWN)
+            return M_PROPERTY_UNKNOWN;
+
+        if (strlen(rem)) {
+            struct m_property_action_arg next_ka = *ka;
+            next_ka.key = rem;
+            return tag_property(prop, M_PROPERTY_KEY_ACTION, &next_ka,
+                                &vf_metadata);
+        } else {
+            return tag_property(prop, ka->action, ka->arg, &vf_metadata);
+        }
+        return M_PROPERTY_OK;
+    }
+    }
+    return M_PROPERTY_UNAVAILABLE;
+}
+
 static int mp_property_pause(m_option_t *prop, int action, void *arg,
                              void *ctx)
 {
@@ -2206,6 +2241,7 @@ static const m_option_t mp_properties[] = {
     { "angle", mp_property_angle, &m_option_type_dummy },
     M_PROPERTY("metadata", mp_property_metadata),
     M_PROPERTY("chapter-metadata", mp_property_chapter_metadata),
+    M_PROPERTY( "vf-metadata", mp_property_vf_metadata),
     M_OPTION_PROPERTY_CUSTOM("pause", mp_property_pause),
     { "cache", mp_property_cache, CONF_TYPE_INT },
     { "cache-size", mp_property_cache_size, CONF_TYPE_INT, M_OPT_MIN, 0 },