transcode: user ENC_FRAMERATE_BASE instead of fixed value

(cherry picked from commit 452cf1c4)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/stream_out/transcode/video.c

@@ -841,7 +841,7 @@ bool transcode_video_add( sout_stream_t *p_stream, es_format_t *p_fmt,
 
     if( p_sys->f_fps > 0 )
     {
-        id->p_encoder->fmt_out.video.i_frame_rate = (p_sys->f_fps * 1000) + 0.5;
+        id->p_encoder->fmt_out.video.i_frame_rate = (p_sys->f_fps * ENC_FRAMERATE_BASE) + 0.5;
         id->p_encoder->fmt_out.video.i_frame_rate_base = ENC_FRAMERATE_BASE;
     }