[x264-devel] Fix VFR MB-tree to work as intended

[Anton Mitrofanov]

x264 | branch: master | Anton Mitrofanov <BugMaster at narod.ru> | Fri Apr 22 01:13:28 2011 +0400| [6e33b51a6571dfc814053096c82538ad278f1868] | committer: Jason Garrett-Glaser

Fix VFR MB-tree to work as intended
Should improve quality with FPSs much larger or smaller than 25.

> http://git.videolan.org/gitweb.cgi/x264.git/?a=commit;h=6e33b51a6571dfc814053096c82538ad278f1868
---

 encoder/ratecontrol.c |   10 +++++++++-
 encoder/slicetype.c   |    8 +++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/encoder/ratecontrol.c b/encoder/ratecontrol.c
index 6726fbd..d28696f 100644
--- a/encoder/ratecontrol.c
+++ b/encoder/ratecontrol.c
@@ -1688,7 +1688,14 @@ static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor
 {
     x264_ratecontrol_t *rcc= h->rc;
     x264_zone_t *zone = get_zone( h, frame_num );
-    double q = pow( rce->blurred_complexity, 1 - rcc->qcompress );
+    double q;
+    if( h->param.rc.b_mb_tree )
+    {
+        double timescale = (double)h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
+        q = pow( BASE_FRAME_DURATION / CLIP_DURATION(rce->i_duration * timescale), 1 - h->param.rc.f_qcompress );
+    }
+    else
+        q = pow( rce->blurred_complexity, 1 - rcc->qcompress );
 
     // avoid NaN's in the rc_eq
     if( !isfinite(q) || rce->tex_bits + rce->mv_bits == 0 )
@@ -2199,6 +2206,7 @@ static float rate_estimate_qscale( x264_t *h )
             rce.s_count = 0;
             rce.qscale = 1;
             rce.pict_type = pict_type;
+            rce.i_duration = h->fenc->i_duration;
 
             if( h->param.rc.i_rc_method == X264_RC_CRF )
             {
diff --git a/encoder/slicetype.c b/encoder/slicetype.c
index 0c9ba7a..4ecdf31 100644
--- a/encoder/slicetype.c
+++ b/encoder/slicetype.c
@@ -752,8 +752,7 @@ static int x264_slicetype_frame_cost_recalculate( x264_t *h, x264_frame_t **fram
 
 static void x264_macroblock_tree_finish( x264_t *h, x264_frame_t *frame, float average_duration, int ref0_distance )
 {
-    int fps_factor_intra     = round( CLIP_DURATION(frame->f_duration) / BASE_FRAME_DURATION * 256 );
-    int fps_factor_propagate = round( CLIP_DURATION( average_duration) / BASE_FRAME_DURATION * 256 );
+    int fps_factor = round( CLIP_DURATION(average_duration) / CLIP_DURATION(frame->f_duration) * 256 );
     float weightdelta = 0.0;
     if( ref0_distance && frame->f_weighted_cost_delta[ref0_distance-1] > 0 )
         weightdelta = (1.0 - frame->f_weighted_cost_delta[ref0_distance-1]);
@@ -764,11 +763,10 @@ static void x264_macroblock_tree_finish( x264_t *h, x264_frame_t *frame, float a
     for( int mb_index = 0; mb_index < h->mb.i_mb_count; mb_index++ )
     {
         int intra_cost = (frame->i_intra_cost[mb_index] * frame->i_inv_qscale_factor[mb_index] + 128) >> 8;
-        int intra_cost_scaled = (intra_cost * fps_factor_intra + 128) >> 8;
         if( intra_cost )
         {
-            int propagate_cost = (frame->i_propagate_cost[mb_index] * fps_factor_propagate + 128) >> 8;
-            float log2_ratio = x264_log2(intra_cost_scaled + propagate_cost) - x264_log2(intra_cost) + weightdelta;
+            int propagate_cost = (frame->i_propagate_cost[mb_index] * fps_factor + 128) >> 8;
+            float log2_ratio = x264_log2(intra_cost + propagate_cost) - x264_log2(intra_cost) + weightdelta;
             frame->f_qp_offset[mb_index] = frame->f_qp_offset_aq[mb_index] - strength * log2_ratio;
         }
     }