From 9c20cedd9365367e19cf3abe0c47fd86377402ee Mon Sep 17 00:00:00 2001 From: Deb Mukherjee Date: Tue, 2 Jul 2013 12:48:20 -0700 Subject: Clean-up in forward update to use mapping tables Uses mapping tables instead of complicated modulo/division operations for prob mapping for forward updates. No bit-stream or output change. Change-Id: Ifd9ce8ac1437835c305c94f64c18273c7a68f546 --- vp9/encoder/vp9_subexp.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) (limited to 'vp9/encoder/vp9_subexp.c') diff --git a/vp9/encoder/vp9_subexp.c b/vp9/encoder/vp9_subexp.c index 044e8e060..01e04d5b0 100644 --- a/vp9/encoder/vp9_subexp.c +++ b/vp9/encoder/vp9_subexp.c @@ -49,17 +49,36 @@ static int recenter_nonneg(int v, int m) { } static int remap_prob(int v, int m) { - const int n = 255; - const int modulus = MODULUS_PARAM; int i; + static int map_table[MAX_PROB - 1] = { + // generated by: + // map_table[j] = split_index(j, MAX_PROB - 1, MODULUS_PARAM); + 20, 21, 22, 23, 24, 25, 0, 26, 27, 28, 29, 30, 31, 32, 33, + 34, 35, 36, 37, 1, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, + 48, 49, 2, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, + 3, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 4, 74, + 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 5, 86, 87, 88, + 89, 90, 91, 92, 93, 94, 95, 96, 97, 6, 98, 99, 100, 101, 102, + 103, 104, 105, 106, 107, 108, 109, 7, 110, 111, 112, 113, 114, 115, 116, + 117, 118, 119, 120, 121, 8, 122, 123, 124, 125, 126, 127, 128, 129, 130, + 131, 132, 133, 9, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, + 145, 10, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 11, + 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 12, 170, 171, + 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 13, 182, 183, 184, 185, + 186, 187, 188, 189, 190, 191, 192, 193, 14, 194, 195, 196, 197, 198, 199, + 200, 201, 202, 203, 204, 205, 15, 206, 207, 208, 209, 210, 211, 212, 213, + 214, 215, 216, 217, 16, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, + 228, 229, 17, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, + 18, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 19, + }; v--; m--; - if ((m << 1) <= n) + if ((m << 1) <= MAX_PROB) i = recenter_nonneg(v, m) - 1; else - i = recenter_nonneg(n - 1 - v, n - 1 - m) - 1; + i = recenter_nonneg(MAX_PROB - 1 - v, MAX_PROB - 1 - m) - 1; - i = split_index(i, n - 1, modulus); + i = map_table[i]; return i; } -- cgit v1.2.3