From ed3b10eb9cffcc346b5a070ce47f5a2beaf9efb6 Mon Sep 17 00:00:00 2001
From: Anton Mitrofanov <BugMaster@narod.ru>
Date: Mon, 6 Jun 2011 13:54:44 +0400
Subject: [PATCH] Fix MBAFF row VBV ratecontrol Reverts most of r1984 and
 implements a much simpler solution.

---
 encoder/encoder.c     | 12 ++----------
 encoder/ratecontrol.c | 14 ++++++++------
 2 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/encoder/encoder.c b/encoder/encoder.c
index d6bcd51b..f8050e0e 100644
--- a/encoder/encoder.c
+++ b/encoder/encoder.c
@@ -2023,7 +2023,6 @@ static int x264_slice_write( x264_t *h )
     i_mb_y = h->sh.i_first_mb / h->mb.i_mb_width;
     i_mb_x = h->sh.i_first_mb % h->mb.i_mb_width;
     i_skip = 0;
-    int mb_size[2];
 
     while( 1 )
     {
@@ -2131,7 +2130,7 @@ reencode:
         }
 
         int total_bits = bs_pos(&h->out.bs) + x264_cabac_pos(&h->cabac);
-        mb_size[i_mb_y&1] = total_bits - mb_spos;
+        int mb_size = total_bits - mb_spos;
 
         if( slice_max_size )
         {
@@ -2253,14 +2252,7 @@ reencode:
         if( b_deblock )
             x264_macroblock_deblock_strength( h );
 
-        if( SLICE_MBAFF )
-        {
-            /* update ratecontrol per-mbpair in MBAFF */
-            if( i_mb_y&1 )
-                x264_ratecontrol_mb( h, mb_size[0]+mb_size[1] );
-        }
-        else
-            x264_ratecontrol_mb( h, mb_size[i_mb_y&1] );
+        x264_ratecontrol_mb( h, mb_size );
 
         if( mb_xy == h->sh.i_last_mb )
             break;
diff --git a/encoder/ratecontrol.c b/encoder/ratecontrol.c
index 87264bfe..97b5ee88 100644
--- a/encoder/ratecontrol.c
+++ b/encoder/ratecontrol.c
@@ -1331,7 +1331,7 @@ static float predict_row_size( x264_t *h, int y, float qscale )
 static int row_bits_so_far( x264_t *h, int y )
 {
     int bits = 0;
-    for( int i = h->i_threadslice_start+SLICE_MBAFF; i <= y; i+=(SLICE_MBAFF+1) )
+    for( int i = h->i_threadslice_start; i <= y; i++ )
         bits += h->fdec->i_row_bits[i];
     return bits;
 }
@@ -1340,7 +1340,7 @@ static float predict_row_size_sum( x264_t *h, int y, float qp )
 {
     float qscale = qp2qscale( qp );
     float bits = row_bits_so_far( h, y );
-    for( int i = y+1+SLICE_MBAFF; i < h->i_threadslice_end; i+=(1+SLICE_MBAFF) )
+    for( int i = y+1; i < h->i_threadslice_end; i++ )
         bits += predict_row_size( h, i, qscale );
     return bits;
 }
@@ -1356,14 +1356,12 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
 
     h->fdec->i_row_bits[y] += bits;
     rc->qpa_aq += h->mb.i_qp;
-    if( SLICE_MBAFF )
-        rc->qpa_aq += h->mb.i_last_qp;
 
     if( h->mb.i_mb_x != h->mb.i_mb_width - 1 )
         return;
 
     x264_emms();
-    rc->qpa_rc += rc->qpm * (h->mb.i_mb_width << SLICE_MBAFF);
+    rc->qpa_rc += rc->qpm * h->mb.i_mb_width;
 
     if( !rc->b_vbv )
         return;
@@ -1376,6 +1374,10 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
     if( h->sh.i_type == SLICE_TYPE_P && rc->qpm < h->fref[0][0]->f_row_qp[y] )
         update_predictor( rc->row_pred[1], qscale, h->fdec->i_row_satds[0][0][y], h->fdec->i_row_bits[y] );
 
+    /* update ratecontrol per-mbpair in MBAFF */
+    if( SLICE_MBAFF && !(y&1) )
+        return;
+
     /* tweak quality based on difference from predicted size */
     if( y < h->i_threadslice_end-1 )
     {
@@ -1390,7 +1392,7 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
         /* B-frames shouldn't use lower QP than their reference frames. */
         if( h->sh.i_type == SLICE_TYPE_B )
         {
-            qp_min = X264_MAX( qp_min, X264_MAX( h->fref[0][0]->f_row_qp[y+1+SLICE_MBAFF], h->fref[1][0]->f_row_qp[y+1+SLICE_MBAFF] ) );
+            qp_min = X264_MAX( qp_min, X264_MAX( h->fref[0][0]->f_row_qp[y+1], h->fref[1][0]->f_row_qp[y+1] ) );
             rc->qpm = X264_MAX( rc->qpm, qp_min );
         }
 
-- 
2.39.2