RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 12:17:35 +00:00
Code Issues Activity Actions

LibVideo/VP9: Remove m_tokens and m_token_cache from Parser

Browse source 
Only the residual tokens array needs to be kept for the transforms to
use after all the tokens have been parsed. The token cache is able to
be kept in the stack only for the duration of the token parsing loop.
This commit is contained in:
Zaggy1024 2022-11-27 00:41:09 -06:00 • committed by Andreas Kling
parent a4f14f220d
commit 316dad7bf7
6 changed files with 32 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

45
Userland/Libraries/LibVideo/VP9/Parser.cpp
View file

@ -1353,6 +1353,7 @@ static TransformSet select_transform_type(BlockContext const& block_context, u8
DecoderErrorOr<bool> Parser::residual(BlockContext& block_context, bool has_block_above, bool has_block_left)
{
bool block_had_non_zero_tokens = false;
Array<u8, 1024> token_cache;
for (u8 plane = 0; plane < 3; plane++) {
auto plane_subsampling_x = (plane > 0) ? block_context.frame_context.color_config.subsampling_x : 0;
auto plane_subsampling_y = (plane > 0) ? block_context.frame_context.color_config.subsampling_y : 0;
@ -1390,7 +1391,7 @@ DecoderErrorOr<bool> Parser::residual(BlockContext& block_context, bool has_bloc
TRY(m_decoder.predict_intra(plane, block_context, transform_x_in_px, transform_y_in_px, has_block_left || x > 0, has_block_above || y > 0, (x + transform_size_in_sub_blocks) < block_size_in_sub_blocks.width(), transform_size, sub_block_index));
if (!block_context.should_skip_residuals) {
auto transform_set = select_transform_type(block_context, plane, transform_size, sub_block_index);
sub_block_had_non_zero_tokens = TRY(tokens(block_context, plane, transform_x_in_px, transform_y_in_px, transform_size, transform_set));
sub_block_had_non_zero_tokens = TRY(tokens(block_context, plane, transform_x_in_px, transform_y_in_px, transform_size, transform_set, token_cache));
block_had_non_zero_tokens = block_had_non_zero_tokens || sub_block_had_non_zero_tokens;
TRY(m_decoder.reconstruct(plane, block_context, transform_x_in_px, transform_y_in_px, transform_size, transform_set));
}
@ -1444,35 +1445,37 @@ static u16 const* get_scan(TransformSize transform_size, TransformSet transform_
return default_scan_32x32;
}
DecoderErrorOr<bool> Parser::tokens(BlockContext& block_context, size_t plane, u32 start_x, u32 start_y, TransformSize transform_size, TransformSet transform_set)
DecoderErrorOr<bool> Parser::tokens(BlockContext& block_context, size_t plane, u32 start_x, u32 start_y, TransformSize transform_size, TransformSet transform_set, Array<u8, 1024> token_cache)
{
u16 segment_eob = 16 << (transform_size << 1);
block_context.residual_tokens.fill(0);
auto const* scan = get_scan(transform_size, transform_set);
auto check_eob = true;
auto check_for_more_coefficients = true;
u16 coef_index = 0;
u16 segment_eob = 16 << (transform_size << 1);
for (; coef_index < segment_eob; coef_index++) {
auto pos = scan[coef_index];
auto band = (transform_size == Transform_4x4) ? coefband_4x4[coef_index] : coefband_8x8plus[coef_index];
auto tokens_context = TreeParser::get_tokens_context(block_context.frame_context.color_config.subsampling_x, block_context.frame_context.color_config.subsampling_y, block_context.frame_context.rows(), block_context.frame_context.columns(), m_above_nonzero_context, m_left_nonzero_context, m_token_cache, transform_size, transform_set, plane, start_x, start_y, pos, block_context.is_inter_predicted(), band, coef_index);
if (check_eob) {
auto more_coefs = TRY_READ(TreeParser::parse_more_coefficients(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, tokens_context));
if (!more_coefs)
break;
}
auto tokens_context = TreeParser::get_tokens_context(block_context.frame_context.color_config.subsampling_x, block_context.frame_context.color_config.subsampling_y, block_context.frame_context.rows(), block_context.frame_context.columns(), m_above_nonzero_context, m_left_nonzero_context, token_cache, transform_size, transform_set, plane, start_x, start_y, pos, block_context.is_inter_predicted(), band, coef_index);
if (check_for_more_coefficients && !TRY_READ(TreeParser::parse_more_coefficients(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, tokens_context)))
break;
auto token = TRY_READ(TreeParser::parse_token(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, tokens_context));
m_token_cache[pos] = energy_class[token];
token_cache[pos] = energy_class[token];
i32 coef;
if (token == ZeroToken) {
m_tokens[pos] = 0;
check_eob = false;
coef = 0;
check_for_more_coefficients = false;
} else {
i32 coef = TRY(read_coef(block_context.frame_context.color_config.bit_depth, token));
bool sign_bit = TRY_READ(m_bit_stream->read_literal(1));
m_tokens[pos] = sign_bit ? -coef : coef;
check_eob = true;
coef = TRY(read_coef(block_context.frame_context.color_config.bit_depth, token));
check_for_more_coefficients = true;
}
block_context.residual_tokens[pos] = coef;
}
for (u16 i = coef_index; i < segment_eob; i++)
m_tokens[scan[i]] = 0;
return coef_index > 0;
}
@ -1480,7 +1483,7 @@ DecoderErrorOr<i32> Parser::read_coef(u8 bit_depth, Token token)
{
auto cat = extra_bits[token][0];
auto num_extra = extra_bits[token][1];
u32 coef = extra_bits[token][2];
i32 coef = extra_bits[token][2];
if (token == DctValCat6) {
for (size_t e = 0; e < (u8)(bit_depth - 8); e++) {
auto high_bit = TRY_READ(m_bit_stream->read_bool(255));
@ -1491,6 +1494,8 @@ DecoderErrorOr<i32> Parser::read_coef(u8 bit_depth, Token token)
auto coef_bit = TRY_READ(m_bit_stream->read_bool(cat_probs[cat][e]));
coef += coef_bit << (num_extra - 1 - e);
}
bool sign_bit = TRY_READ(m_bit_stream->read_literal(1));
coef = sign_bit ? -coef : coef;
return coef;
}