diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c
index b9b18f2576..c232bbdc8f 100644
--- a/libavdevice/avdevice.c
+++ b/libavdevice/avdevice.c
@@ -36,3 +36,11 @@ const char * avdevice_license(void)
 #define LICENSE_PREFIX "libavdevice license: "
     return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
 }
+
+int avdevice_app_to_dev_control_message(struct AVFormatContext *s, enum AVAppToDevMessageType type,
+                                        void *data, size_t data_size)
+{
+    if (!s->oformat || !s->oformat->control_message)
+        return AVERROR(ENOSYS);
+    return s->oformat->control_message(s, type, data, data_size);
+}
diff --git a/libavdevice/avdevice.h b/libavdevice/avdevice.h
index 93a044f270..1bc91e4d0f 100644
--- a/libavdevice/avdevice.h
+++ b/libavdevice/avdevice.h
@@ -66,4 +66,56 @@ const char *avdevice_license(void);
  */
 void avdevice_register_all(void);
 
+typedef struct AVDeviceRect {
+    int x;      /**< x coordinate of top left corner */
+    int y;      /**< y coordinate of top left corner */
+    int width;  /**< width */
+    int height; /**< height */
+} AVDeviceRect;
+
+/**
+ * Message types used by avdevice_app_to_dev_control_message().
+ */
+enum AVAppToDevMessageType {
+    /**
+     * Dummy message.
+     */
+    AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'),
+
+    /**
+     * Window size change message.
+     *
+     * Message is sent to the device every time the application changes the size
+     * of the window device renders to.
+     * Message should also be sent right after window is created.
+     *
+     * data: AVDeviceRect: new window size.
+     */
+    AV_APP_TO_DEV_WINDOW_SIZE = MKBETAG('G','E','O','M'),
+
+    /**
+     * Repaint request message.
+     *
+     * Message is sent to the device when window have to be rapainted.
+     *
+     * data: AVDeviceRect: area required to be repainted.
+     *       NULL: whole area is required to be repainted.
+     */
+    AV_APP_TO_DEV_WINDOW_REPAINT = MKBETAG('R','E','P','A')
+};
+
+/**
+ * Send control message from application to device.
+ *
+ * @param s         device context.
+ * @param type      message type.
+ * @param data      message data. Exact type depends on message type.
+ * @param data_size size of message data.
+ * @return >= 0 on success, negative on error.
+ *         AVERROR(ENOSYS) when device doesn't implement handler of the message.
+ */
+int avdevice_app_to_dev_control_message(struct AVFormatContext *s,
+                                        enum AVAppToDevMessageType type,
+                                        void *data, size_t data_size);
+
 #endif /* AVDEVICE_AVDEVICE_H */
diff --git a/libavdevice/version.h b/libavdevice/version.h
index d569faefc5..bfd4a7089d 100644
--- a/libavdevice/version.h
+++ b/libavdevice/version.h
@@ -28,8 +28,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVDEVICE_VERSION_MAJOR  55
-#define LIBAVDEVICE_VERSION_MINOR   5
-#define LIBAVDEVICE_VERSION_MICRO 102
+#define LIBAVDEVICE_VERSION_MINOR   6
+#define LIBAVDEVICE_VERSION_MICRO 100
 
 #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \
                                                LIBAVDEVICE_VERSION_MINOR, \
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index a495ee0b79..09eea74ad9 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -453,6 +453,11 @@ typedef struct AVOutputFormat {
 
     void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
                                  int64_t *dts, int64_t *wall);
+    /**
+     * Allows sending messages from application to device.
+     */
+    int (*control_message)(struct AVFormatContext *s, int type,
+                           void *data, size_t data_size);
 } AVOutputFormat;
 /**
  * @}
diff --git a/libavformat/version.h b/libavformat/version.h
index a0e5a7cee9..51f6d598d9 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 55
-#define LIBAVFORMAT_VERSION_MINOR 26
+#define LIBAVFORMAT_VERSION_MINOR 27
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \