[x264-devel] Fix zone bitrate multiplier and QP forcing in 2-pass mode

[Anton Mitrofanov]

x264 | branch: master | Anton Mitrofanov <BugMaster at narod.ru> | Thu May  5 16:27:49 2011 +0400| [c132d7b5b76a526e1ba519db6be894b19fd2647f] | committer: Jason Garrett-Glaser

Fix zone bitrate multiplier and QP forcing in 2-pass mode
Previously zone changes could affect frames outside of the given frame range (around 20 neighboring frames).

> http://git.videolan.org/gitweb.cgi/x264.git/?a=commit;h=c132d7b5b76a526e1ba519db6be894b19fd2647f
---

 encoder/ratecontrol.c |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/encoder/ratecontrol.c b/encoder/ratecontrol.c
index 37336f7..d6e89b7 100644
--- a/encoder/ratecontrol.c
+++ b/encoder/ratecontrol.c
@@ -1720,10 +1720,11 @@ static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor
     return q;
 }
 
-static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
+static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q, int frame_num)
 {
     x264_ratecontrol_t *rcc = h->rc;
     const int pict_type = rce->pict_type;
+    x264_zone_t *zone = get_zone( h, frame_num );
 
     // force I/B quants as a function of P quants
     const double last_p_q    = rcc->last_qscale_for[SLICE_TYPE_P];
@@ -1784,6 +1785,15 @@ static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
         rcc->accum_p_qp   = mask * (qscale2qp( q ) + rcc->accum_p_qp);
         rcc->accum_p_norm = mask * (1 + rcc->accum_p_norm);
     }
+
+    if( zone )
+    {
+        if( zone->b_force_qp )
+            q = qp2qscale( zone->i_qp );
+        else
+            q /= zone->f_bitrate_factor;
+    }
+
     return q;
 }
 
@@ -2662,14 +2672,14 @@ static int init_pass2( x264_t *h )
         /* find qscale */
         for( int i = 0; i < rcc->num_entries; i++ )
         {
-            qscale[i] = get_qscale( h, &rcc->entry[i], rate_factor, i );
+            qscale[i] = get_qscale( h, &rcc->entry[i], rate_factor, -1 );
             rcc->last_qscale_for[rcc->entry[i].pict_type] = qscale[i];
         }
 
         /* fixed I/B qscale relative to P */
         for( int i = rcc->num_entries-1; i >= 0; i-- )
         {
-            qscale[i] = get_diff_limited_q( h, &rcc->entry[i], qscale[i] );
+            qscale[i] = get_diff_limited_q( h, &rcc->entry[i], qscale[i], i );
             assert(qscale[i] >= 0);
         }