Index: encoder/ratecontrol.c
===================================================================
--- encoder/ratecontrol.c	(revision 680)
+++ encoder/ratecontrol.c	(working copy)
@@ -352,6 +352,7 @@
             return -1;
         }
         rc->num_entries = i;
+        h->param.rc_num_entries = i;
 
         if( h->param.i_frame_total < rc->num_entries && h->param.i_frame_total > 0 )
         {
Index: x264.c
===================================================================
--- x264.c	(revision 680)
+++ x264.c	(working copy)
@@ -763,6 +763,13 @@
         return -1;
     }
 
+    if ( ( param->rc.b_stat_read == 2 ) && ( i_frame_total == 0 ) )
+    {
+        i_frame_total=h->param.rc_num_entries;
+        x264_log( h, X264_LOG_INFO, "using %d frames discovered from first pass for eta calculations.\n"
+                ,i_frame_total);
+    }
+
     if( p_set_outfile_param( opt->hout, param ) )
     {
         fprintf( stderr, "x264 [error]: can't set outfile param\n" );
Index: x264.h
===================================================================
--- x264.h	(revision 680)
+++ x264.h	(working copy)
@@ -147,6 +147,7 @@
     int         i_csp;  /* CSP of encoded bitstream, only i420 supported */
     int         i_level_idc; 
     int         i_frame_total; /* number of frames to encode if known, else 0 */
+    int         rc_num_entries; /* Number of frames found by RC, used for fifo eta*/
 
     struct
     {