api: allow to change A/R on the fly.

ASF allows specifying a new aspect ratio while playing back.
Triggering change using the "aspect-ratio" variable can't work
for unknown A/R as the variable is "Checked" type.

include/vlc_vout.h

@@ -145,6 +145,9 @@ VLC_API int vout_GetSnapshot( vout_thread_t *p_vout,
                               video_format_t *p_fmt,
                               const char *psz_format, mtime_t i_timeout );
 
+VLC_API void vout_ChangeAspectRatio( vout_thread_t *p_vout,
+                                     unsigned int i_num, unsigned int i_den );
+
 /* */
 VLC_API picture_t * vout_GetPicture( vout_thread_t * );
 VLC_API void vout_PutPicture( vout_thread_t *, picture_t * );

src/libvlccore.sym

@@ -593,6 +593,7 @@ vlm_MessageDelete
 vlm_MessageNew
 vlm_MessageSimpleNew
 vlm_New
+vout_ChangeAspectRatio
 vout_Close
 vout_GetPicture
 vout_PutPicture

src/video_output/video_output.c

@@ -487,6 +487,12 @@ int vout_GetSnapshot(vout_thread_t *vout,
     return VLC_SUCCESS;
 }
 
+void vout_ChangeAspectRatio( vout_thread_t *p_vout,
+                             unsigned int i_num, unsigned int i_den )
+{
+    vout_ControlChangeSampleAspectRatio( p_vout, i_num, i_den );
+}
+
 /* vout_Control* are usable by anyone at anytime */
 void vout_ControlChangeFullscreen(vout_thread_t *vout, bool fullscreen)
 {