ref: c64a27801c76593074aac18561175251ab897653
parent: 583f2d8fc7edeaf9d8eec5b928a485334a5b8544
author: Deb Mukherjee <debargha@google.com>
date: Fri Feb 24 04:08:00 EST 2012
Changing default 8-tap filter to Langrangian interpolator. The Lagrangian interpolation filter is maximally flat in the passband. There is non-trivial improvement with the hd set, while for derf the results are virtually unchanged. See: http://www.corp.google.com/~debargha/vp8_results/enhinterpn.html (derf) http://www.corp.google.com/~debargha/vp8_results/enhinterpn_hd.html (HD) Patch 2: Updated the results for derf in the html above to use the new baseline. There is still about 4% improvement. Will update the hd baseline later (since it takes 9 hours to run on my machine) Patch 3: By mistake the default filter was left at 60 - should be 0 to use the new interpolation filter. Change-Id: If5f64444976562415d68a2aeabb94fdfa0d47890
--- a/vp8/common/filter.c
+++ b/vp8/common/filter.c
@@ -45,7 +45,7 @@
};
#if CONFIG_ENHANCED_INTERP
-#define FILTER_ALPHA 60
+#define FILTER_ALPHA 0
DECLARE_ALIGNED(16, const short, vp8_sub_pel_filters[SUBPEL_SHIFTS][2*INTERP_EXTEND]) =
{/* Generated using MATLAB:
@@ -56,25 +56,7 @@
* disp(num2str(ba, '%d,'))
*/
#if SUBPEL_SHIFTS==16
-#if FILTER_ALPHA == 75
- /* alpha = 0.75 */
- { 0, 0, 0, 128, 0, 0, 0, 0},- {-1, 2, -6, 126, 9, -3, 2, -1},- {-1, 4, -11, 123, 18, -7, 3, -1},- {-2, 6, -16, 119, 28, -10, 5, -2},- {-2, 7, -19, 113, 38, -13, 6, -2},- {-3, 8, -21, 106, 49, -16, 7, -2},- {-3, 9, -22, 99, 59, -19, 8, -3},- {-3, 9, -23, 90, 70, -21, 9, -3},- {-3, 9, -22, 80, 80, -22, 9, -3},- {-3, 9, -21, 70, 90, -23, 9, -3},- {-3, 8, -19, 59, 99, -22, 9, -3},- {-2, 7, -16, 49, 106, -21, 8, -3},- {-2, 6, -13, 38, 113, -19, 7, -2},- {-2, 5, -10, 28, 119, -16, 6, -2},- {-1, 3, -7, 18, 123, -11, 4, -1},- {-1, 2, -3, 9, 126, -6, 2, -1}-#elif FILTER_ALPHA == 70
+#if FILTER_ALPHA == 70
/* alpha = 0.70 */
{ 0, 0, 0, 128, 0, 0, 0, 0}, { 0, 2, -6, 126, 8, -3, 1, 0},@@ -109,7 +91,7 @@
{-1, 5, -13, 38, 112, -17, 5, -1}, {-1, 4, -10, 27, 118, -14, 5, -1}, {-1, 2, -6, 18, 123, -10, 3, -1},- {0, 1, -3, 8, 126, -6, 2, 0}+ { 0, 1, -3, 8, 126, -6, 2, 0}#elif FILTER_ALPHA == 60
/* alpha = 0.60 */
{ 0, 0, 0, 128, 0, 0, 0, 0},@@ -127,11 +109,11 @@
{-1, 4, -12, 38, 112, -17, 5, -1}, {-1, 3, -9, 28, 118, -14, 4, -1}, {-1, 2, -6, 18, 123, -10, 3, -1},- {0, 1, -3, 8, 126, -6, 2, 0}+ { 0, 1, -3, 8, 126, -6, 2, 0}#elif FILTER_ALPHA == 55
/* alpha = 0.55 */
- {0, 0, 0, 128, 0, 0, 0, 0},- {0, 1, -5, 126, 8, -3, 1, 0},+ { 0, 0, 0, 128, 0, 0, 0, 0},+ { 0, 1, -5, 126, 8, -3, 1, 0}, {-1, 2, -10, 123, 18, -6, 2, 0}, {-1, 4, -13, 118, 27, -9, 3, -1}, {-1, 5, -16, 112, 37, -12, 4, -1},@@ -144,21 +126,47 @@
{-1, 4, -14, 48, 105, -18, 5, -1}, {-1, 4, -12, 37, 112, -16, 5, -1}, {-1, 3, -9, 27, 118, -13, 4, -1},- {0, 2, -6, 18, 123, -10, 2, -1},- {0, 1, -3, 8, 126, -5, 1, 0}+ { 0, 2, -6, 18, 123, -10, 2, -1},+ { 0, 1, -3, 8, 126, -5, 1, 0}+#elif FILTER_ALPHA == 50
+ /* alpha = 0.50 */
+ { 0, 0, 0, 128, 0, 0, 0, 0},+ { 0, 1, -5, 126, 8, -3, 1, 0},+ { 0, 2, -10, 122, 18, -6, 2, 0},+ {-1, 3, -13, 118, 27, -9, 3, 0},+ {-1, 4, -16, 112, 37, -11, 3, 0},+ {-1, 5, -17, 104, 48, -14, 4, -1},+ {-1, 5, -18, 96, 58, -16, 5, -1},+ {-1, 5, -19, 88, 68, -17, 5, -1},+ {-1, 5, -18, 78, 78, -18, 5, -1},+ {-1, 5, -17, 68, 88, -19, 5, -1},+ {-1, 5, -16, 58, 96, -18, 5, -1},+ {-1, 4, -14, 48, 104, -17, 5, -1},+ { 0, 3, -11, 37, 112, -16, 4, -1},+ { 0, 3, -9, 27, 118, -13, 3, -1},+ { 0, 2, -6, 18, 122, -10, 2, 0},+ { 0, 1, -3, 8, 126, -5, 1, 0}+#elif FILTER_ALPHA == 0
+ /* Lagrangian interpolation filter */
+ { 0, 0, 0, 128, 0, 0, 0, 0},+ { 0, 1, -5, 126, 8, -3, 1, 0},+ {-1, 3, -10, 122, 18, -6, 2, 0},+ {-1, 4, -13, 118, 27, -9, 3, -1},+ {-1, 4, -16, 112, 37, -11, 4, -1},+ {-1, 5, -18, 105, 48, -14, 4, -1},+ {-1, 5, -19, 97, 58, -16, 5, -1},+ {-1, 6, -19, 88, 68, -18, 5, -1},+ {-1, 6, -19, 78, 78, -19, 6, -1},+ {-1, 5, -18, 68, 88, -19, 6, -1},+ {-1, 5, -16, 58, 97, -19, 5, -1},+ {-1, 4, -14, 48, 105, -18, 5, -1},+ {-1, 4, -11, 37, 112, -16, 4, -1},+ {-1, 3, -9, 27, 118, -13, 4, -1},+ { 0, 2, -6, 18, 122, -10, 3, -1},+ { 0, 1, -3, 8, 126, -5, 1, 0}#endif /* FILTER_ALPHA */
#else /* SUBPEL_SHIFTS==16 */
-#if FILTER_ALPHA == 75
- /* alpha = 0.75 */
- { 0, 0, 0, 128, 0, 0, 0, 0},- {-1, 4, -11, 123, 18, -7, 3, -1},- {-2, 7, -19, 113, 38, -13, 6, -2},- {-3, 9, -22, 99, 59, -19, 8, -3},- {-3, 9, -22, 80, 80, -22, 9, -3},- {-3, 8, -19, 59, 99, -22, 9, -3},- {-2, 6, -13, 38, 113, -19, 7, -2},- {-1, 3, -7, 18, 123, -11, 4, -1}-#elif FILTER_ALPHA == 70
+#if FILTER_ALPHA == 70
/* alpha = 0.70 */
{ 0, 0, 0, 128, 0, 0, 0, 0}, {-1, 4, -11, 123, 18, -7, 3, -1},@@ -198,6 +206,26 @@
{-1, 5, -16, 58, 97, -19, 5, -1}, {-1, 4, -12, 37, 112, -16, 5, -1}, { 0, 2, -6, 18, 123, -10, 2, -1}+#elif FILTER_ALPHA == 50
+ /* alpha = 0.50 */
+ { 0, 0, 0, 128, 0, 0, 0, 0},+ { 0, 2, -10, 122, 18, -6, 2, 0},+ {-1, 4, -16, 112, 37, -11, 3, 0},+ {-1, 5, -18, 96, 58, -16, 5, -1},+ {-1, 5, -18, 78, 78, -18, 5, -1},+ {-1, 5, -16, 58, 96, -18, 5, -1},+ { 0, 3, -11, 37, 112, -16, 4, -1},+ { 0, 2, -6, 18, 122, -10, 2, 0}+#elif FILTER_ALPHA == 0
+ /* Lagrangian interpolation filter */
+ { 0, 0, 0, 128, 0, 0, 0, 0},+ {-1, 3, -10, 122, 18, -6, 2, 0},+ {-1, 4, -16, 112, 37, -11, 4, -1},+ {-1, 5, -19, 97, 58, -16, 5, -1},+ {-1, 6, -19, 78, 78, -19, 6, -1},+ {-1, 5, -16, 58, 97, -19, 5, -1},+ {-1, 4, -11, 37, 112, -16, 4, -1},+ { 0, 2, -6, 18, 122, -10, 3, -1},#endif /* FILTER_ALPHA */
#endif /* SUBPEL_SHIFTS==16 */
};