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authortrav90 <travawine@palemoon.org>2018-10-18 21:53:44 -0500
committertrav90 <travawine@palemoon.org>2018-10-18 21:53:44 -0500
commitec910d81405c736a4490383a250299a7837c2e64 (patch)
tree4f27cc226f93a863121aef6c56313e4153a69b3e /third_party/aom/av1/encoder/hash.c
parent01eb57073ba97b2d6cbf20f745dfcc508197adc3 (diff)
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Update aom to commit id e87fb2378f01103d5d6e477a4ef6892dc714e614
Diffstat (limited to 'third_party/aom/av1/encoder/hash.c')
-rw-r--r--third_party/aom/av1/encoder/hash.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/hash.c b/third_party/aom/av1/encoder/hash.c
new file mode 100644
index 000000000..89c5bd8a3
--- /dev/null
+++ b/third_party/aom/av1/encoder/hash.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include "av1/encoder/hash.h"
+
+static void crc_calculator_process_data(CRC_CALCULATOR *p_crc_calculator,
+ uint8_t *pData, uint32_t dataLength) {
+ for (uint32_t i = 0; i < dataLength; i++) {
+ const uint8_t index =
+ (p_crc_calculator->remainder >> (p_crc_calculator->bits - 8)) ^
+ pData[i];
+ p_crc_calculator->remainder <<= 8;
+ p_crc_calculator->remainder ^= p_crc_calculator->table[index];
+ }
+}
+
+void crc_calculator_reset(CRC_CALCULATOR *p_crc_calculator) {
+ p_crc_calculator->remainder = 0;
+}
+
+static uint32_t crc_calculator_get_crc(CRC_CALCULATOR *p_crc_calculator) {
+ return p_crc_calculator->remainder & p_crc_calculator->final_result_mask;
+}
+
+static void crc_calculator_init_table(CRC_CALCULATOR *p_crc_calculator) {
+ const uint32_t high_bit = 1 << (p_crc_calculator->bits - 1);
+ const uint32_t byte_high_bit = 1 << (8 - 1);
+
+ for (uint32_t value = 0; value < 256; value++) {
+ uint32_t remainder = 0;
+ for (uint8_t mask = byte_high_bit; mask != 0; mask >>= 1) {
+ if (value & mask) {
+ remainder ^= high_bit;
+ }
+
+ if (remainder & high_bit) {
+ remainder <<= 1;
+ remainder ^= p_crc_calculator->trunc_poly;
+ } else {
+ remainder <<= 1;
+ }
+ }
+ p_crc_calculator->table[value] = remainder;
+ }
+}
+
+void av1_crc_calculator_init(CRC_CALCULATOR *p_crc_calculator, uint32_t bits,
+ uint32_t truncPoly) {
+ p_crc_calculator->remainder = 0;
+ p_crc_calculator->bits = bits;
+ p_crc_calculator->trunc_poly = truncPoly;
+ p_crc_calculator->final_result_mask = (1 << bits) - 1;
+ crc_calculator_init_table(p_crc_calculator);
+}
+
+uint32_t av1_get_crc_value(CRC_CALCULATOR *p_crc_calculator, uint8_t *p,
+ int length) {
+ crc_calculator_reset(p_crc_calculator);
+ crc_calculator_process_data(p_crc_calculator, p, length);
+ return crc_calculator_get_crc(p_crc_calculator);
+}