Fix possible non-determinism with mbtree + open-gop + sync-lookahead

[x264] / encoder / lookahead.c

diff --git a/encoder/lookahead.c b/encoder/lookahead.c
index c99f117927faf118da6c8b6ac85b4d8aa256bf09..ad8a3e68bf823b6003fd764bf73b82642988ab38 100644 (file)
--- a/encoder/lookahead.c
+++ b/encoder/lookahead.c
@@ -70,18 +70,19 @@ static void x264_lookahead_slicetype_decide( x264_t *h )
     x264_stack_align( x264_slicetype_decide, h );
 
     x264_lookahead_update_last_nonb( h, h->lookahead->next.list[0] );
+    int shift_frames = h->lookahead->next.list[0]->i_bframes + 1;
 
     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
     while( h->lookahead->ofbuf.i_size == h->lookahead->ofbuf.i_max_size )
         x264_pthread_cond_wait( &h->lookahead->ofbuf.cv_empty, &h->lookahead->ofbuf.mutex );
 
     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
-    x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, h->lookahead->next.list[0]->i_bframes + 1 );
+    x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, shift_frames );
     x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
 
     /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
     if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
-        x264_stack_align( x264_slicetype_analyse, h, 1 );
+        x264_stack_align( x264_slicetype_analyse, h, shift_frames );
 
     x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
 }
@@ -236,11 +237,12 @@ void x264_lookahead_get_frames( x264_t *h )
 
         x264_stack_align( x264_slicetype_decide, h );
         x264_lookahead_update_last_nonb( h, h->lookahead->next.list[0] );
-        x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, h->lookahead->next.list[0]->i_bframes + 1 );
+        int shift_frames = h->lookahead->next.list[0]->i_bframes + 1;
+        x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, shift_frames );
 
         /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
         if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
-            x264_stack_align( x264_slicetype_analyse, h, 1 );
+            x264_stack_align( x264_slicetype_analyse, h, shift_frames );
 
         x264_lookahead_encoder_shift( h );
     }