[x264-devel] Use the correct default B-ref placement with B-pyramid

[Anton Mitrofanov]

x264 | branch: master | Anton Mitrofanov <BugMaster at narod.ru> | Sun Apr 10 20:13:59 2016 +0300| [fd2c324731c2199e502ded9eff723d29c6eafe0b] | committer: Henrik Gramner

Use the correct default B-ref placement with B-pyramid

Cost analyse functions expects the placement of the B-ref in a sequence of
an even number of B-frames to be located towards the beginning while the
actual placement was towards the end.

Change the placement to be consistent with the analyse expectations, e.g.
PbbBbP -> PbBbbP.

> http://git.videolan.org/gitweb.cgi/x264.git/?a=commit;h=fd2c324731c2199e502ded9eff723d29c6eafe0b
---

 encoder/slicetype.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/encoder/slicetype.c b/encoder/slicetype.c
index d7fcb9d..32540be 100644
--- a/encoder/slicetype.c
+++ b/encoder/slicetype.c
@@ -1928,7 +1928,7 @@ void x264_slicetype_decide( x264_t *h )
     /* insert a bref into the sequence */
     if( h->param.i_bframe_pyramid && bframes > 1 && !brefs )
     {
-        h->lookahead->next.list[bframes/2]->i_type = X264_TYPE_BREF;
+        h->lookahead->next.list[(bframes-1)/2]->i_type = X264_TYPE_BREF;
         brefs++;
     }