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LibVideo: Parameterize parsing of the default VP9 intra mode tree

This commit is contained in:
Zaggy1024 2022-11-06 19:18:03 -06:00 committed by Andrew Kaster
parent fce7639c90
commit c6ecad63d0
4 changed files with 56 additions and 39 deletions

View file

@ -1017,8 +1017,19 @@ DecoderErrorOr<void> Parser::intra_frame_mode_info()
m_ref_frame[0] = IntraFrame;
m_ref_frame[1] = None;
m_is_inter = false;
// FIXME: This if statement is also present in parse_default_intra_mode. The selection of parameters for
// the probability table lookup should be inlined here.
if (m_mi_size >= Block_8x8) {
m_default_intra_mode = TRY_READ(m_tree_parser->parse_tree<PredictionMode>(SyntaxElementType::DefaultIntraMode));
// FIXME: This context should be available in the block setup. Make a struct to store the context
// that is needed to call the tree parses and set it in decode_block().
auto above_context = Optional<Array<PredictionMode, 4> const&>();
auto left_context = Optional<Array<PredictionMode, 4> const&>();
if (m_available_u)
above_context = m_sub_modes[get_image_index(m_mi_row - 1, m_mi_col)];
if (m_available_l)
left_context = m_sub_modes[get_image_index(m_mi_row, m_mi_col - 1)];
m_default_intra_mode = TRY_READ(TreeParser::parse_default_intra_mode(*m_bit_stream, *m_probability_tables, m_mi_size, above_context, left_context, m_block_sub_modes, 0, 0));
m_y_mode = m_default_intra_mode;
for (auto& block_sub_mode : m_block_sub_modes)
block_sub_mode = m_y_mode;
@ -1027,8 +1038,15 @@ DecoderErrorOr<void> Parser::intra_frame_mode_info()
m_num_4x4_h = num_4x4_blocks_high_lookup[m_mi_size];
for (auto idy = 0; idy < 2; idy += m_num_4x4_h) {
for (auto idx = 0; idx < 2; idx += m_num_4x4_w) {
m_tree_parser->set_default_intra_mode_variables(idx, idy);
m_default_intra_mode = TRY_READ(m_tree_parser->parse_tree<PredictionMode>(SyntaxElementType::DefaultIntraMode));
// FIXME: See the FIXME above.
auto above_context = Optional<Array<PredictionMode, 4> const&>();
auto left_context = Optional<Array<PredictionMode, 4> const&>();
if (m_available_u)
above_context = m_sub_modes[get_image_index(m_mi_row - 1, m_mi_col)];
if (m_available_l)
left_context = m_sub_modes[get_image_index(m_mi_row, m_mi_col - 1)];
m_default_intra_mode = TRY_READ(TreeParser::parse_default_intra_mode(*m_bit_stream, *m_probability_tables, m_mi_size, above_context, left_context, m_block_sub_modes, idx, idy));
for (auto y = 0; y < m_num_4x4_h; y++) {
for (auto x = 0; x < m_num_4x4_w; x++) {
auto index = (idy + y) * 2 + idx + x;

View file

@ -243,6 +243,9 @@ private:
u8 m_num_4x4_w { 0 };
u8 m_num_4x4_h { 0 };
PredictionMode m_uv_mode { 0 }; // FIXME: Is u8 the right size?
// FIXME: From spec: NOTE We are using a 2D array to store the SubModes for clarity. It is possible to reduce memory
// consumption by only storing one intra mode for each 8x8 horizontal and vertical position, i.e. to use two 1D
// arrays instead.
Vector<Array<PredictionMode, 4>> m_sub_modes;
ReferenceFramePair m_left_ref_frame;
ReferenceFramePair m_above_ref_frame;

View file

@ -7,10 +7,10 @@
#include <AK/Function.h>
#include "TreeParser.h"
#include "Enums.h"
#include "LookupTables.h"
#include "Parser.h"
#include "TreeParser.h"
namespace Video::VP9 {
@ -104,13 +104,42 @@ ErrorOr<Partition> TreeParser::parse_partition(BitStream& bit_stream, Probabilit
return value;
}
ErrorOr<PredictionMode> TreeParser::parse_default_intra_mode(BitStream& bit_stream, ProbabilityTables const& probability_table, BlockSubsize mi_size, Optional<Array<PredictionMode, 4> const&> above_context, Optional<Array<PredictionMode, 4> const&> left_context, PredictionMode block_sub_modes[4], u8 index_x, u8 index_y)
{
// FIXME: This should use a struct for the above and left contexts.
// Tree
TreeParser::TreeSelection tree = { intra_mode_tree };
// Probabilities
PredictionMode above_mode, left_mode;
if (mi_size >= Block_8x8) {
above_mode = above_context.has_value() ? above_context.value()[2] : PredictionMode::DcPred;
left_mode = left_context.has_value() ? left_context.value()[1] : PredictionMode::DcPred;
} else {
if (index_y > 0)
above_mode = block_sub_modes[index_x];
else
above_mode = above_context.has_value() ? above_context.value()[2 + index_x] : PredictionMode::DcPred;
if (index_x > 0)
left_mode = block_sub_modes[index_y << 1];
else
left_mode = left_context.has_value() ? left_context.value()[1 + (index_y << 1)] : PredictionMode::DcPred;
}
u8 const* probabilities = probability_table.kf_y_mode_probs()[to_underlying(above_mode)][to_underlying(left_mode)];
auto value = TRY(parse_tree_new<PredictionMode>(bit_stream, tree, [&](u8 node) { return probabilities[node]; }));
// Default intra mode is not counted.
return value;
}
/*
* Select a tree value based on the type of syntax element being parsed, as well as some parser state, as specified in section 9.3.1
*/
TreeParser::TreeSelection TreeParser::select_tree(SyntaxElementType type)
{
switch (type) {
case SyntaxElementType::DefaultIntraMode:
case SyntaxElementType::DefaultUVMode:
case SyntaxElementType::IntraMode:
case SyntaxElementType::SubIntraMode:
@ -166,8 +195,6 @@ TreeParser::TreeSelection TreeParser::select_tree(SyntaxElementType type)
u8 TreeParser::select_tree_probability(SyntaxElementType type, u8 node)
{
switch (type) {
case SyntaxElementType::DefaultIntraMode:
return calculate_default_intra_mode_probability(node);
case SyntaxElementType::DefaultUVMode:
return calculate_default_uv_mode_probability(node);
case SyntaxElementType::IntraMode:
@ -241,36 +268,6 @@ u8 TreeParser::select_tree_probability(SyntaxElementType type, u8 node)
#define ABOVE_SINGLE m_decoder.m_above_single
#define LEFT_SINGLE m_decoder.m_left_single
u8 TreeParser::calculate_default_intra_mode_probability(u8 node)
{
PredictionMode above_mode, left_mode;
if (m_decoder.m_mi_size >= Block_8x8) {
above_mode = AVAIL_U
? m_decoder.m_sub_modes[m_decoder.get_image_index(m_decoder.m_mi_row - 1, m_decoder.m_mi_col)][2]
: PredictionMode::DcPred;
left_mode = AVAIL_L
? m_decoder.m_sub_modes[m_decoder.get_image_index(m_decoder.m_mi_row, m_decoder.m_mi_col - 1)][1]
: PredictionMode::DcPred;
} else {
if (m_idy) {
above_mode = m_decoder.m_block_sub_modes[m_idx];
} else {
above_mode = AVAIL_U
? m_decoder.m_sub_modes[m_decoder.get_image_index(m_decoder.m_mi_row - 1, m_decoder.m_mi_col)][2 + m_idx]
: PredictionMode::DcPred;
}
if (m_idx) {
left_mode = m_decoder.m_block_sub_modes[m_idy * 2];
} else {
left_mode = AVAIL_L
? m_decoder.m_sub_modes[m_decoder.get_image_index(m_decoder.m_mi_row, m_decoder.m_mi_col - 1)][1 + m_idy * 2]
: PredictionMode::DcPred;
}
}
return m_decoder.m_probability_tables->kf_y_mode_probs()[to_underlying(above_mode)][to_underlying(left_mode)][node];
}
u8 TreeParser::calculate_default_uv_mode_probability(u8 node)
{
return m_decoder.m_probability_tables->kf_uv_mode_prob()[to_underlying(m_decoder.m_y_mode)][node];
@ -772,7 +769,6 @@ void TreeParser::count_syntax_element(SyntaxElementType type, int value)
case SyntaxElementType::MoreCoefs:
increment(m_decoder.m_syntax_element_counter->m_counts_more_coefs[m_tx_size][m_plane > 0][m_decoder.m_is_inter][m_band][m_ctx][value]);
return;
case SyntaxElementType::DefaultIntraMode:
case SyntaxElementType::DefaultUVMode:
case SyntaxElementType::SegmentID:
case SyntaxElementType::SegIDPredicted:

View file

@ -63,6 +63,7 @@ public:
void count_syntax_element(SyntaxElementType type, int value);
static ErrorOr<Partition> parse_partition(BitStream&, ProbabilityTables const&, SyntaxElementCounter&, bool has_rows, bool has_columns, BlockSubsize block_subsize, u8 num_8x8, Vector<u8> const& above_partition_context, Vector<u8> const& left_partition_context, u32 row, u32 column, bool frame_is_intra);
static ErrorOr<PredictionMode> parse_default_intra_mode(BitStream&, ProbabilityTables const&, BlockSubsize mi_size, Optional<Array<PredictionMode, 4> const&> above_context, Optional<Array<PredictionMode, 4> const&> left_context, PredictionMode block_sub_modes[4], u8 index_x, u8 index_y);
void set_default_intra_mode_variables(u8 idx, u8 idy)
{
@ -96,7 +97,6 @@ public:
}
private:
u8 calculate_default_intra_mode_probability(u8 node);
u8 calculate_default_uv_mode_probability(u8 node);
u8 calculate_intra_mode_probability(u8 node);
u8 calculate_sub_intra_mode_probability(u8 node);