per context frame_rate_base, this should finally fix frame_rate related av sync issues

Originally committed as revision 1666 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/apiexample.c

@@ -192,7 +192,8 @@ void video_encode_example(const char *filename)
     c->width = 352;  
     c->height = 288;
     /* frames per second */
-    c->frame_rate = 25 * FRAME_RATE_BASE;  
+    c->frame_rate = 25;  
+    c->frame_rate_base= 1;
     c->gop_size = 10; /* emit one intra frame every ten frames */
 
     /* open it */