1 files changed, 64 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/coeff_order.h b/third_party/jpeg-xl/lib/jxl/coeff_order.h
new file mode 100644
index 0000000000..fb32499f2f
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/coeff_order.h
@@ -0,0 +1,64 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#ifndef LIB_JXL_COEFF_ORDER_H_
+#define LIB_JXL_COEFF_ORDER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "lib/jxl/ac_strategy.h"
+#include "lib/jxl/base/compiler_specific.h"
+#include "lib/jxl/base/status.h"
+#include "lib/jxl/coeff_order_fwd.h"
+#include "lib/jxl/common.h"
+#include "lib/jxl/dct_util.h"
+
+namespace jxl {
+
+class BitReader;
+
+// Those offsets get multiplied by kDCTBlockSize.
+static constexpr size_t kCoeffOrderOffset[] = {
+    0,    1,    2,    3,    4,    5,    6,    10,   14,   18,
+    34,   50,   66,   68,   70,   72,   76,   80,   84,   92,
+    100,  108,  172,  236,  300,  332,  364,  396,  652,  908,
+    1164, 1292, 1420, 1548, 2572, 3596, 4620, 5132, 5644, 6156,
+};
+static_assert(3 * kNumOrders + 1 ==
+                  sizeof(kCoeffOrderOffset) / sizeof(*kCoeffOrderOffset),
+              "Update this array when adding or removing order types.");
+
+static constexpr size_t CoeffOrderOffset(size_t order, size_t c) {
+  return kCoeffOrderOffset[3 * order + c] * kDCTBlockSize;
+}
+
+static constexpr size_t kCoeffOrderMaxSize =
+    kCoeffOrderOffset[3 * kNumOrders] * kDCTBlockSize;
+
+// Mapping from AC strategy to order bucket. Strategies with different natural
+// orders must have different buckets.
+constexpr uint8_t kStrategyOrder[] = {
+    0, 1, 1, 1, 2, 3, 4, 4, 5,  5,  6,  6,  1,  1,
+    1, 1, 1, 1, 7, 8, 8, 9, 10, 10, 11, 12, 12,
+};
+
+static_assert(AcStrategy::kNumValidStrategies ==
+                  sizeof(kStrategyOrder) / sizeof(*kStrategyOrder),
+              "Update this array when adding or removing AC strategies.");
+
+constexpr uint32_t kPermutationContexts = 8;
+
+uint32_t CoeffOrderContext(uint32_t val);
+
+Status DecodeCoeffOrders(uint16_t used_orders, uint32_t used_acs,
+                         coeff_order_t* order, BitReader* br);
+
+Status DecodePermutation(size_t skip, size_t size, coeff_order_t* order,
+                         BitReader* br);
+
+}  // namespace jxl
+
+#endif  // LIB_JXL_COEFF_ORDER_H_