mux/asf.c: Workaround for playback of WMV in WMP12 and Silverlight.

The maximum bitrate of the file is not allowed to become zero. If it
is then playback in WMP12 and Silverlight does not work. The actual
value for maximum bitrate does not really matter in these cases as
long as it is not 0.

modules/mux/asf.c

@@ -943,7 +943,10 @@ static block_t *asf_header_create( sout_mux_t *p_mux, bool b_broadcast )
     bo_addle_u32( &bo, b_broadcast ? 0x01 : 0x02 /* seekable */ ); /* flags */
     bo_addle_u32( &bo, p_sys->i_packet_size );  /* packet size min */
     bo_addle_u32( &bo, p_sys->i_packet_size );  /* packet size max */
-    bo_addle_u32( &bo, p_sys->i_bitrate );      /* maxbitrate */
+    /* NOTE: According to p6-9 of the ASF specification the bitrate cannot be 0,
+     * therefor apply this workaround to make sure it is not 0. If the bitrate is
+     * 0 the file will play in WMP11, but not in Sliverlight and WMP12 */
+    bo_addle_u32( &bo, p_sys->i_bitrate > 0 ? p_sys->i_bitrate : 1 ); /* maxbitrate */
 
     /* header extension */
     bo_add_guid ( &bo, &asf_object_header_extension_guid );