common_video/h265/h265_inline.cc

/*
 *  Copyright (c) 2023 The WebRTC 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 in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "common_video/h265/h265_inline.h"

#include <stdint.h>

// Table used by WebRtcVideo_CountLeadingZeros32_NotBuiltin. For each uint32_t n
// that's a sequence of 0 bits followed by a sequence of 1 bits, the entry at
// index (n * 0x8c0b2891) >> 26 in this table gives the number of zero bits in
// n.
const int8_t kWebRtcVideo_CountLeadingZeros32_Table[64] = {
    32, 8,  17, -1, -1, 14, -1, -1, -1, 20, -1, -1, -1, 28, -1, 18,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0,  26, 25, 24,
    4,  11, 23, 31, 3,  7,  10, 16, 22, 30, -1, -1, 2,  6,  13, 9,
    -1, 15, -1, 21, -1, 29, 19, -1, -1, -1, -1, -1, 1,  27, 5,  12,
};