mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 18:02:44 +00:00
6e6cc1ddb2
Bit reversals are used very often in intra-predicted frames. Turning these into a constexpr lookup table reduces the branching needed for block transforms significantly. This reduces the times spent decoding an intra-heavy 1080p video by about 9% (~14.3s -> ~12.9s).
138 lines
3 KiB
C++
138 lines
3 KiB
C++
/*
|
|
* Copyright (c) 2021, Hunter Salyer <thefalsehonesty@gmail.com>
|
|
* Copyright (c) 2022, Gregory Bertilson <zaggy1024@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Types.h>
|
|
#include <LibGfx/Size.h>
|
|
|
|
#include "LookupTables.h"
|
|
|
|
namespace Video::VP9 {
|
|
|
|
// FIXME: Once everything is working, replace this with plain clamp
|
|
// since parameter order is different
|
|
template<typename T>
|
|
T clip_3(T x, T y, T z)
|
|
{
|
|
return clamp(z, x, y);
|
|
}
|
|
|
|
template<typename T>
|
|
u16 clip_1(u8 bit_depth, T x)
|
|
{
|
|
if (x < 0) {
|
|
return 0u;
|
|
}
|
|
const T max = (1u << bit_depth) - 1u;
|
|
if (x > max)
|
|
return max;
|
|
return x;
|
|
}
|
|
|
|
template<u8 bits>
|
|
inline u8 brev(u8 value)
|
|
{
|
|
static_assert(bits <= 8, "brev() expects an 8-bit value.");
|
|
|
|
static constexpr auto lookup_table = [] {
|
|
constexpr size_t value_count = 1 << bits;
|
|
Array<u8, value_count> the_table;
|
|
for (u8 lookup_value = 0; lookup_value < value_count; lookup_value++) {
|
|
u8 reversed = 0;
|
|
for (u8 bit_index = 0; bit_index < bits; bit_index++) {
|
|
auto bit = (lookup_value >> bit_index) & 1;
|
|
reversed |= bit << (bits - 1 - bit_index);
|
|
}
|
|
the_table[lookup_value] = reversed;
|
|
}
|
|
return the_table;
|
|
}();
|
|
|
|
return lookup_table[value];
|
|
}
|
|
|
|
inline BlockSubsize get_subsampled_block_size(BlockSubsize size, bool subsampling_x, bool subsampling_y)
|
|
{
|
|
return ss_size_lookup[size < Block_8x8 ? Block_8x8 : size][subsampling_x][subsampling_y];
|
|
}
|
|
|
|
inline Gfx::Size<u8> block_size_to_blocks(BlockSubsize size)
|
|
{
|
|
return Gfx::Size<u8>(num_8x8_blocks_wide_lookup[size], num_8x8_blocks_high_lookup[size]);
|
|
}
|
|
|
|
inline Gfx::Size<u8> block_size_to_sub_blocks(BlockSubsize size)
|
|
{
|
|
return Gfx::Size<u8>(num_4x4_blocks_wide_lookup[size], num_4x4_blocks_high_lookup[size]);
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T blocks_to_superblocks(T blocks)
|
|
{
|
|
return blocks >> 3;
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T superblocks_to_blocks(T superblocks)
|
|
{
|
|
return superblocks << 3;
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T blocks_ceiled_to_superblocks(T blocks)
|
|
{
|
|
return blocks_to_superblocks(blocks + 7);
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T blocks_to_sub_blocks(T blocks)
|
|
{
|
|
return blocks << 1;
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T sub_blocks_to_blocks(T sub_blocks)
|
|
{
|
|
return sub_blocks >> 1;
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T sub_blocks_to_pixels(T sub_blocks)
|
|
{
|
|
return sub_blocks << 2;
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T pixels_to_sub_blocks(T pixels)
|
|
{
|
|
return pixels >> 2;
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T blocks_to_pixels(T blocks)
|
|
{
|
|
return sub_blocks_to_pixels(blocks_to_sub_blocks(blocks));
|
|
}
|
|
|
|
template<Integral T>
|
|
inline T pixels_to_blocks(T pixels)
|
|
{
|
|
return sub_blocks_to_blocks(pixels_to_sub_blocks(pixels));
|
|
}
|
|
|
|
inline u8 transform_size_to_sub_blocks(TransformSize transform_size)
|
|
{
|
|
return 1 << transform_size;
|
|
}
|
|
|
|
inline u32 y_size_to_uv_size(bool subsampled, u32 size)
|
|
{
|
|
return (size + subsampled) >> subsampled;
|
|
}
|
|
|
|
}
|