[x265] [PATCH 7 of 7] docs: update threading details of lookahead

[Steve Borho]

# HG changeset patch
# User Steve Borho <steve at borho.org>
# Date 1427387063 18000
#      Thu Mar 26 11:24:23 2015 -0500
# Node ID dc7a6c5fbda13173004e6193f185ea857d7a22c8
# Parent  6c9e3e8f8ec6fa86ab8fcea0712d31ead6003753
docs: update threading details of lookahead

diff -r 6c9e3e8f8ec6 -r dc7a6c5fbda1 doc/reST/threading.rst
--- a/doc/reST/threading.rst	Thu Mar 26 11:22:58 2015 -0500
+++ b/doc/reST/threading.rst	Thu Mar 26 11:24:23 2015 -0500
@@ -223,7 +223,8 @@
 The lookahead module of x265 (the lowres pre-encode which determines
 scene cuts and slice types) uses the thread pool to distribute the
 lowres cost analysis to worker threads. It will use bonded task groups
-to perform batches of frame cost estimates.
+to perform batches of frame cost estimates, and it may optionally use
+bonded task groups to measure single frame cost estimates using slices.
 
 The function slicetypeDecide() itself is also be performed by a worker
 thread if your encoder has a thread pool, else it runs within the