f_output_chain: log status of auto filters

Just so users don't think the filters do anything when they don't insert
any filters.

filters/f_auto_filters.c

@@ -106,9 +106,21 @@ static void deint_destroy(struct mp_filter *f)
     TA_FREEP(&p->sub.filter);
 }
 
+static bool deint_command(struct mp_filter *f, struct mp_filter_command *cmd)
+{
+    struct deint_priv *p = f->priv;
+
+    if (cmd->type == MP_FILTER_COMMAND_IS_ACTIVE) {
+        cmd->is_active = !!p->sub.filter;
+        return true;
+    }
+    return false;
+}
+
 static const struct mp_filter_info deint_filter = {
     .name = "deint",
     .priv_size = sizeof(struct deint_priv),
+    .command = deint_command,
     .process = deint_process,
     .reset = deint_reset,
     .destroy = deint_destroy,
@@ -220,9 +232,21 @@ static void rotate_destroy(struct mp_filter *f)
     TA_FREEP(&p->sub.filter);
 }
 
+static bool rotate_command(struct mp_filter *f, struct mp_filter_command *cmd)
+{
+    struct rotate_priv *p = f->priv;
+
+    if (cmd->type == MP_FILTER_COMMAND_IS_ACTIVE) {
+        cmd->is_active = !!p->sub.filter;
+        return true;
+    }
+    return false;
+}
+
 static const struct mp_filter_info rotate_filter = {
     .name = "autorotate",
     .priv_size = sizeof(struct rotate_priv),
+    .command = rotate_command,
     .process = rotate_process,
     .reset = rotate_reset,
     .destroy = rotate_destroy,
@@ -291,6 +315,11 @@ static bool aspeed_command(struct mp_filter *f, struct mp_filter_command *cmd)
         return true;
     }
 
+    if (cmd->type == MP_FILTER_COMMAND_IS_ACTIVE) {
+        cmd->is_active = !!p->sub.filter;
+        return true;
+    }
+
     return false;
 }
 

filters/f_autoconvert.c

@@ -418,6 +418,11 @@ static bool command(struct mp_filter *f, struct mp_filter_command *cmd)
         return true;
     }
 
+    if (cmd->type == MP_FILTER_COMMAND_IS_ACTIVE) {
+        cmd->is_active = !!p->sub.filter;
+        return true;
+    }
+
     return false;
 }
 

filters/f_output_chain.c

@@ -66,6 +66,8 @@ struct mp_user_filter {
     struct mp_image_params last_in_vformat;
     struct mp_aframe *last_in_aformat;
 
+    bool last_is_active;
+
     int64_t last_in_pts, last_out_pts;
 
     bool failed;
@@ -198,6 +200,13 @@ static void process_user(struct mp_filter *f)
             u->last_out_pts = pts;
 
         mp_pin_in_write(f->ppins[1], frame);
+
+        struct mp_filter_command cmd = {.type = MP_FILTER_COMMAND_IS_ACTIVE};
+        if (mp_filter_command(u->f, &cmd) && u->last_is_active != cmd.is_active) {
+            u->last_is_active = cmd.is_active;
+            MP_VERBOSE(p, "[%s] (%sabled)\n", u->name,
+                       u->last_is_active ? "en" : "dis");
+        }
     }
 }
 
@@ -236,6 +245,7 @@ static struct mp_user_filter *create_wrapper_filter(struct chain *p)
     wrapper->wrapper = f;
     wrapper->p = p;
     wrapper->last_in_aformat = talloc_steal(wrapper, mp_aframe_create());
+    wrapper->last_is_active = true;
     mp_filter_add_pin(f, MP_PIN_IN, "in");
     mp_filter_add_pin(f, MP_PIN_OUT, "out");
     return wrapper;

filters/filter.h

@@ -357,6 +357,7 @@ enum mp_filter_command_type {
     MP_FILTER_COMMAND_GET_META,
     MP_FILTER_COMMAND_SET_SPEED,
     MP_FILTER_COMMAND_SET_SPEED_RESAMPLE,
+    MP_FILTER_COMMAND_IS_ACTIVE,
 };
 
 struct mp_filter_command {
@@ -371,6 +372,9 @@ struct mp_filter_command {
 
     // For MP_FILTER_COMMAND_SET_SPEED and MP_FILTER_COMMAND_SET_SPEED_RESAMPLE
     double speed;
+
+    // For MP_FILTER_COMMAND_IS_ACTIVE
+    bool is_active;
 };
 
 // Run a command on the filter. Returns success. For libavfilter.