stream: add const to format event

src/examples/video-play.c

@@ -221,7 +221,7 @@ static Uint32 id_to_sdl_format(struct data *data, uint32_t id)
 }
 
 static void
-on_stream_format_changed(void *_data, struct spa_pod *format)
+on_stream_format_changed(void *_data, const struct spa_pod *format)
 {
 	struct data *data = _data;
 	struct pw_stream *stream = data->stream;

src/examples/video-src.c

@@ -160,7 +160,7 @@ static void on_stream_state_changed(void *_data, enum pw_stream_state old, enum
 }
 
 static void
-on_stream_format_changed(void *_data, struct spa_pod *format)
+on_stream_format_changed(void *_data, const struct spa_pod *format)
 {
 	struct data *data = _data;
 	struct pw_stream *stream = data->stream;

src/gst/gstpipewiresink.c

@@ -496,7 +496,7 @@ on_state_changed (void *data, enum pw_stream_state old, enum pw_stream_state sta
 }
 
 static void
-on_format_changed (void *data, struct spa_pod *format)
+on_format_changed (void *data, const struct spa_pod *format)
 {
   GstPipeWireSink *pwsink = data;
 

src/gst/gstpipewiresrc.c

@@ -682,8 +682,8 @@ connect_error:
 #define SPA_PROP_RANGE(min,max)	2,min,max
 
 static void
-on_format_changed (void           *data,
+on_format_changed (void *data,
-                   struct spa_pod *format)
+                   const struct spa_pod *format)
 {
   GstPipeWireSrc *pwsrc = data;
   GstCaps *caps;

src/pipewire/stream.h

@@ -180,7 +180,7 @@ struct pw_stream_events {
 	/** when the format changed. The listener should call
 	 * pw_stream_finish_format() from within this callback or later to complete
 	 * the format negotiation and start the buffer negotiation. */
-	void (*format_changed) (void *data, struct spa_pod *format);
+	void (*format_changed) (void *data, const struct spa_pod *format);
 
         /** when a new buffer was created for this stream */
         void (*add_buffer) (void *data, struct pw_buffer *buffer);