shithub: libvpx

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Force the bit exactness in the first pass

Originally, for the purpose of keeping a fast first pass, the first-pass
stats between row_mt_mode = 0 and row_mt_mode = 1 are not bit exact, but
that difference is very small that doesn't cause a mismatch between the
final bitstreams. However, if the encoder changes, this minor difference
may cause a mismatch. Thus, this patch always forces the first pass to
be bit exact.

BUG=webm:1453

Change-Id: I2b67cf529dee81f660f9d9e7fe9a60ea3c7b12b8

--- a/test/vp9_ethread_test.cc

+++ b/test/vp9_ethread_test.cc

@@ -340,8 +340,6 @@

   ASSERT_EQ(single_thr_md5, multi_thr_md5);

   // Part 2: row_mt_mode_ = 0 vs row_mt_mode_ = 1 single thread bit exact test.

-  // The first-pass stats are not bit exact here, but that difference doesn't

-  // cause a mismatch between the final bitstreams.

   row_mt_mode_ = 1;

   // Encode using single thread

--- a/vp9/encoder/vp9_encoder.c

+++ b/vp9/encoder/vp9_encoder.c

@@ -5589,7 +5589,7 @@

     cpi->row_mt = 1;

   }

-  if (cpi->row_mt && cpi->oxcf.max_threads > 1)

+  if (cpi->row_mt)

     cpi->row_mt_bit_exact = 1;

   else

     cpi->row_mt_bit_exact = 0;

--- a/vp9/encoder/vp9_speed_features.c

+++ b/vp9/encoder/vp9_speed_features.c

@@ -664,7 +664,8 @@

   // and multiple threads match.

   // It can be used in realtime when adaptive_rd_thresh_row_mt is enabled since

   // adaptive_rd_thresh is defined per-row for non-rd pickmode.

-  if (!sf->adaptive_rd_thresh_row_mt && cpi->row_mt_bit_exact)

+  if (!sf->adaptive_rd_thresh_row_mt && cpi->row_mt_bit_exact &&

+      oxcf->max_threads > 1)

     sf->adaptive_rd_thresh = 0;

   // This is only used in motion vector unit test.

@@ -820,7 +821,8 @@

   // and multiple threads match.

   // It can be used in realtime when adaptive_rd_thresh_row_mt is enabled since

   // adaptive_rd_thresh is defined per-row for non-rd pickmode.

-  if (!sf->adaptive_rd_thresh_row_mt && cpi->row_mt_bit_exact)

+  if (!sf->adaptive_rd_thresh_row_mt && cpi->row_mt_bit_exact &&

+      oxcf->max_threads > 1)

     sf->adaptive_rd_thresh = 0;

   // This is only used in motion vector unit test.