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| author | Deb Mukherjee <debargha@google.com> | 2012-03-28 15:19:45 -0700 |
|---|---|---|
| committer | Deb Mukherjee <debargha@google.com> | 2012-03-29 08:39:02 -0700 |
| commit | 78ecbc98e4df70e94e8f2029c8d2d65f643e6f74 (patch) | |
| tree | 13e825a4e34475441f9cff49a54cbeb47c3666b4 /vp8 | |
| parent | 9f900a1c6404464edd23d2d43a3ab1f390ec8af7 (diff) | |
| download | libvpx-78ecbc98e4df70e94e8f2029c8d2d65f643e6f74.tar libvpx-78ecbc98e4df70e94e8f2029c8d2d65f643e6f74.tar.gz libvpx-78ecbc98e4df70e94e8f2029c8d2d65f643e6f74.tar.bz2 libvpx-78ecbc98e4df70e94e8f2029c8d2d65f643e6f74.zip | |
Bug fix in probability update savings computation
Found this bug while tracking down some anomalies in my experiments.
Since vp8_cost_one and vp8_cost_zero return unsigned int, the
bit shift by 8 will be incorrect if the value is negative.
I am cautiously optimistic that this fix will make the prob
updates more correct and somewhat improve results across the board.
But the update probabilities will need to be retuned I think.
Patch 2: Adding more of the same fixes using a macro.
Change-Id: I1a168f040e74e8c67e7225103b1c2af9a611da49
Diffstat (limited to 'vp8')
| -rw-r--r-- | vp8/encoder/bitstream.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/vp8/encoder/bitstream.c b/vp8/encoder/bitstream.c index b698618a6..7288ead68 100644 --- a/vp8/encoder/bitstream.c +++ b/vp8/encoder/bitstream.c @@ -44,6 +44,8 @@ extern unsigned int active_section; int count_mb_seg[4] = { 0, 0, 0, 0 }; #endif +#define vp8_cost_upd ((int)(vp8_cost_one(upd) - vp8_cost_zero(upd)) >> 8) + static void update_mode( vp8_writer *const w, int n, @@ -157,8 +159,7 @@ static int prob_update_savings(const unsigned int *ct, { const int old_b = vp8_cost_branch(ct, oldp); const int new_b = vp8_cost_branch(ct, newp); - const int update_b = 8 + - ((vp8_cost_one(upd) - vp8_cost_zero(upd)) >> 8); + const int update_b = 8 + vp8_cost_upd; return old_b - new_b - update_b; } @@ -1330,8 +1331,7 @@ int vp8_estimate_entropy_savings(VP8_COMP *cpi) const int old_b = vp8_cost_branch(ct, old); const int new_b = vp8_cost_branch(ct, newp); - const int update_b = 8 + - ((vp8_cost_one(upd) - vp8_cost_zero(upd)) >> 8); + const int update_b = 8 + vp8_cost_upd; const int s = old_b - new_b - update_b; @@ -1519,8 +1519,7 @@ static void update_coef_probs(VP8_COMP *cpi) const vp8_prob upd = vp8_coef_update_probs_8x8 [i][j][k][t]; const int old_b = vp8_cost_branch(ct, old); const int new_b = vp8_cost_branch(ct, newp); - const int update_b = 8 + - ((vp8_cost_one(upd) - vp8_cost_zero(upd)) >> 8); + const int update_b = 8 + vp8_cost_upd; const int s = old_b - new_b - update_b; const int u = s > 0 ? 1 : 0; @@ -1586,8 +1585,7 @@ static void update_coef_probs(VP8_COMP *cpi) const vp8_prob upd = vp8_coef_update_probs_8x8 [i][j][k][t]; const int old_b = vp8_cost_branch(ct, old); const int new_b = vp8_cost_branch(ct, newp); - const int update_b = 8 + - ((vp8_cost_one(upd) - vp8_cost_zero(upd)) >> 8); + const int update_b = 8 + vp8_cost_upd; const int s = old_b - new_b - update_b; const int u = s > 0 ? 1 : 0; vp8_write(w, u, upd); |