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Refactoring: AV2 spec v1.0.0 uses ..minus_1 and not minus1 #4

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Merged
joelsole merged 1 commit into from
Jun 16, 2026
Merged

Refactoring: AV2 spec v1.0.0 uses ..minus_1 and not minus1 #4

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8 changes: 4 additions & 4 deletions include/av2_obu/core/av2_sequence_header.h
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Original file line number Diff line number Diff line change
Expand Up @@ -53,7 +53,7 @@ struct SequencePartitionConfig {
uint32_t enable_ext_partitions = 0;
uint32_t enable_uneven_4way_partitions = 0;
uint32_t reduce_pb_aspect_ratio = 0;
uint32_t max_pb_aspect_ratio_log2_minus1 = 0;
uint32_t max_pb_aspect_ratio_log2_minus_1 = 0;

// Computed values
uint32_t MaxPbAspectRatio = 8;
Expand Down Expand Up @@ -104,9 +104,9 @@ struct SequenceInterConfig {
uint32_t explicit_ref_frame_map = 0;
uint32_t explicit_num_ref_frames = 0;
uint32_t num_ref_frames_minus_1 = 0;
uint32_t seq_max_drl_bits_minus1 = 0;
uint32_t seq_max_drl_bits_minus_1 = 0;
uint32_t allow_frame_max_drl_bits = 0;
uint32_t seq_max_bvp_drl_bits_minus1 = 0;
uint32_t seq_max_bvp_drl_bits_minus_1 = 0;
uint32_t allow_frame_max_bvp_drl_bits = 0;
uint32_t num_same_ref_compound = 0;
uint32_t enable_tip = 0;
Expand Down Expand Up @@ -197,7 +197,7 @@ struct SequenceFilterConfig {
uint32_t ccso_unit_matches_sb_size = 0;
uint32_t cdef_on_skip_txfm_always_on = 0;
uint32_t cdef_on_skip_txfm_disabled = 0;
uint32_t df_par_bits_minus2 = 0;
uint32_t df_par_bits_minus_2 = 0;

// Computed values
uint32_t CdefOnSkipTxfm = CDEF_ON_SKIP_TXFM_ADAPTIVE;
Expand Down
18 changes: 9 additions & 9 deletions include/av2_obu/obus/atlas_segment_obu.h
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Expand Up @@ -42,15 +42,15 @@ class AtlasSegmentOBU : public BaseOBU {
};

struct EnhancedAtlasInfo {
uint32_t num_region_columns_minus1 = 0;
uint32_t num_region_rows_minus1 = 0;
uint32_t num_region_columns_minus_1 = 0;
uint32_t num_region_rows_minus_1 = 0;
uint32_t uniform_spacing_flag = 0;
std::vector<uint32_t> column_width_minus1;
std::vector<uint32_t> row_height_minus1;
uint32_t region_width_minus1 = 0;
uint32_t region_height_minus1 = 0;
std::vector<uint32_t> column_width_minus_1;
std::vector<uint32_t> row_height_minus_1;
uint32_t region_width_minus_1 = 0;
uint32_t region_height_minus_1 = 0;
uint32_t single_region_per_segment_flag = 0;
uint32_t num_atlas_segments_minus1 = 0;
uint32_t num_atlas_segments_minus_1 = 0;
struct SegmentRegion {
uint32_t top_left_col = 0;
uint32_t top_left_row = 0;
Expand Down Expand Up @@ -81,8 +81,8 @@ class AtlasSegmentOBU : public BaseOBU {
uint32_t basic_height_ = 0;

// Mode 2 — SINGLE_ATLAS
uint32_t nominal_width_minus1_ = 0;
uint32_t nominal_height_minus1_ = 0;
uint32_t nominal_width_minus_1_ = 0;
uint32_t nominal_height_minus_1_ = 0;

// Modes 3 & 4 — MULTISTREAM_ATLAS / MULTISTREAM_ALPHA_ATLAS
uint32_t msi_width_ = 0;
Expand Down
8 changes: 4 additions & 4 deletions include/av2_obu/obus/metadata_unit.h
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Original file line number Diff line number Diff line change
Expand Up @@ -120,8 +120,8 @@ class MetadataUnit {
// BANDING_HINTS
struct BandingComponentInfo {
uint8_t banding_in_component_present_flag = 0;
uint8_t max_band_width_minus4 = 0;
uint8_t max_band_step_minus1 = 0;
uint8_t max_band_width_minus_4 = 0;
uint8_t max_band_step_minus_1 = 0;
};

uint8_t coding_banding_present_flag_ = 0;
Expand All @@ -134,8 +134,8 @@ class MetadataUnit {
uint8_t num_band_units_cols_minus_1_ = 0;
uint8_t varying_size_band_units_flag_ = 0;
uint8_t band_block_in_luma_samples_ = 0;
std::vector<uint8_t> vert_size_in_band_blocks_minus1_;
std::vector<uint8_t> horz_size_in_band_blocks_minus1_;
std::vector<uint8_t> vert_size_in_band_blocks_minus_1_;
std::vector<uint8_t> horz_size_in_band_blocks_minus_1_;
std::vector<std::vector<uint8_t>> banding_in_band_unit_present_flags_; // 2D array [rows][cols]
};

Expand Down
18 changes: 9 additions & 9 deletions src/core/av2_sequence_header.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -103,8 +103,8 @@ bool SequencePartitionConfig::parse(BitstreamReader& br, bool single_picture_hea

reduce_pb_aspect_ratio = br.read_bit();
if (reduce_pb_aspect_ratio) {
max_pb_aspect_ratio_log2_minus1 = br.read_bit();
MaxPbAspectRatio = 1 << (max_pb_aspect_ratio_log2_minus1 + 1);
max_pb_aspect_ratio_log2_minus_1 = br.read_bit();
MaxPbAspectRatio = 1 << (max_pb_aspect_ratio_log2_minus_1 + 1);
} else {
MaxPbAspectRatio = 8;
}
Expand Down Expand Up @@ -239,7 +239,7 @@ bool SequenceInterConfig::parse(BitstreamReader& br, bool single_picture_header_
DrlReorder = constrain_drl_reorder ? DRL_REORDER_CONSTRAINT : DRL_REORDER_ALWAYS;
}

seq_max_bvp_drl_bits_minus1 = br.read_ns(MAX_REF_BV_STACK_SIZE - 1);
seq_max_bvp_drl_bits_minus_1 = br.read_ns(MAX_REF_BV_STACK_SIZE - 1);
allow_frame_max_bvp_drl_bits = br.read_bit();

enable_bawp = br.read_bit();
Expand Down Expand Up @@ -303,10 +303,10 @@ bool SequenceInterConfig::parse(BitstreamReader& br, bool single_picture_header_

long_term_frame_id_bits = br.read_bits(3);

seq_max_drl_bits_minus1 = br.read_ns(MAX_REF_MV_STACK_SIZE - 1);
seq_max_drl_bits_minus_1 = br.read_ns(MAX_REF_MV_STACK_SIZE - 1);
allow_frame_max_drl_bits = br.read_bit();

seq_max_bvp_drl_bits_minus1 = br.read_ns(MAX_REF_BV_STACK_SIZE - 1);
seq_max_bvp_drl_bits_minus_1 = br.read_ns(MAX_REF_BV_STACK_SIZE - 1);
allow_frame_max_bvp_drl_bits = br.read_bit();

num_same_ref_compound = br.read_bits(2);
Expand Down Expand Up @@ -373,9 +373,9 @@ json SequenceInterConfig::to_json() const {
{"NumRefFrames", NumRefFrames},
{"ActiveNumRefFrames", ActiveNumRefFrames},
{"long_term_frame_id_bits", long_term_frame_id_bits},
{"seq_max_drl_bits_minus1", seq_max_drl_bits_minus1},
{"seq_max_drl_bits_minus_1", seq_max_drl_bits_minus_1},
{"allow_frame_max_drl_bits", allow_frame_max_drl_bits},
{"seq_max_bvp_drl_bits_minus1", seq_max_bvp_drl_bits_minus1},
{"seq_max_bvp_drl_bits_minus_1", seq_max_bvp_drl_bits_minus_1},
{"allow_frame_max_bvp_drl_bits", allow_frame_max_bvp_drl_bits},
{"num_same_ref_compound", num_same_ref_compound},
{"enable_tip", enable_tip},
Expand Down Expand Up @@ -617,7 +617,7 @@ bool SequenceFilterConfig::parse(BitstreamReader& br, bool single_picture_header
}
}

df_par_bits_minus2 = br.read_bits(2);
df_par_bits_minus_2 = br.read_bits(2);

return true;
}
Expand All @@ -631,7 +631,7 @@ json SequenceFilterConfig::to_json() const {
{"enable_ccso", enable_ccso},
{"ccso_unit_matches_sb_size", ccso_unit_matches_sb_size},
{"CdefOnSkipTxfm", CdefOnSkipTxfm},
{"df_par_bits_minus2", df_par_bits_minus2}};
{"df_par_bits_minus_2", df_par_bits_minus_2}};
}

// ==================== SequenceTileConfig ====================
Expand Down
54 changes: 27 additions & 27 deletions src/obus/atlas_segment_obu.cpp
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Expand Up @@ -32,24 +32,24 @@ static const char* mode_name(AtlasSegmentOBU::ModeIdc m) {
// ats_region_info() — returns NumRegionsInAtlas
static uint32_t parse_region_info(BitstreamReader& br,
AtlasSegmentOBU::EnhancedAtlasInfo& info) {
info.num_region_columns_minus1 = br.read_uvlc();
info.num_region_rows_minus1 = br.read_uvlc();
info.num_region_columns_minus_1 = br.read_uvlc();
info.num_region_rows_minus_1 = br.read_uvlc();
info.uniform_spacing_flag = br.read_bit();

if (!info.uniform_spacing_flag) {
uint32_t num_cols = info.num_region_columns_minus1 + 1;
uint32_t num_rows = info.num_region_rows_minus1 + 1;
info.column_width_minus1.resize(num_cols);
info.row_height_minus1.resize(num_rows);
uint32_t num_cols = info.num_region_columns_minus_1 + 1;
uint32_t num_rows = info.num_region_rows_minus_1 + 1;
info.column_width_minus_1.resize(num_cols);
info.row_height_minus_1.resize(num_rows);
for (uint32_t i = 0; i < num_cols; i++)
info.column_width_minus1[i] = br.read_uvlc();
info.column_width_minus_1[i] = br.read_uvlc();
for (uint32_t i = 0; i < num_rows; i++)
info.row_height_minus1[i] = br.read_uvlc();
info.row_height_minus_1[i] = br.read_uvlc();
} else {
info.region_width_minus1 = br.read_uvlc();
info.region_height_minus1 = br.read_uvlc();
info.region_width_minus_1 = br.read_uvlc();
info.region_height_minus_1 = br.read_uvlc();
}
return (info.num_region_columns_minus1 + 1) * (info.num_region_rows_minus1 + 1);
return (info.num_region_columns_minus_1 + 1) * (info.num_region_rows_minus_1 + 1);
}

// ats_region_to_segment_mapping() — returns numSegments
Expand All @@ -58,8 +58,8 @@ static uint32_t parse_region_to_segment_mapping(BitstreamReader& br,
uint32_t num_regions) {
info.single_region_per_segment_flag = br.read_bit();
if (!info.single_region_per_segment_flag) {
info.num_atlas_segments_minus1 = br.read_uvlc();
uint32_t n = info.num_atlas_segments_minus1 + 1;
info.num_atlas_segments_minus_1 = br.read_uvlc();
uint32_t n = info.num_atlas_segments_minus_1 + 1;
info.segment_regions.resize(n);
for (uint32_t i = 0; i < n; i++) {
info.segment_regions[i].top_left_col = br.read_uvlc();
Expand All @@ -69,7 +69,7 @@ static uint32_t parse_region_to_segment_mapping(BitstreamReader& br,
}
return n;
} else {
info.num_atlas_segments_minus1 = num_regions - 1;
info.num_atlas_segments_minus_1 = num_regions - 1;
return num_regions;
}
}
Expand Down Expand Up @@ -114,7 +114,7 @@ bool AtlasSegmentOBU::parse_payload(std::ifstream& ifs) {
basic_stream_id_present_ = br.read_bit();
basic_width_ = br.read_uvlc();
basic_height_ = br.read_uvlc();
uint32_t n = br.read_uvlc() + 1; // ats_num_atlas_segments_minus1 + 1
uint32_t n = br.read_uvlc() + 1; // ats_num_atlas_segments_minus_1 + 1
num_segments = n;
segments_.resize(n);
for (uint32_t i = 0; i < n; i++) {
Expand All @@ -128,8 +128,8 @@ bool AtlasSegmentOBU::parse_payload(std::ifstream& ifs) {
break;
}
case ModeIdc::SINGLE_ATLAS: {
nominal_width_minus1_ = br.read_uvlc();
nominal_height_minus1_ = br.read_uvlc();
nominal_width_minus_1_ = br.read_uvlc();
nominal_height_minus_1_ = br.read_uvlc();
num_segments = 1;
break;
}
Expand All @@ -138,7 +138,7 @@ bool AtlasSegmentOBU::parse_payload(std::ifstream& ifs) {
bool with_alpha = (mode_idc_ == ModeIdc::MULTISTREAM_ALPHA_ATLAS);
msi_width_ = br.read_uvlc();
msi_height_ = br.read_uvlc();
uint32_t n = br.read_uvlc() + 1; // ats_msi_num_atlas_segments_minus1 + 1
uint32_t n = br.read_uvlc() + 1; // ats_msi_num_atlas_segments_minus_1 + 1
num_segments = n;
if (with_alpha)
msi_alpha_segments_present_ = br.read_bit();
Expand Down Expand Up @@ -192,18 +192,18 @@ json AtlasSegmentOBU::to_json() const {
switch (mode_idc_) {
case ModeIdc::ENHANCED_ATLAS: {
json e;
e["ats_num_region_columns_minus_1"] = enhanced_.num_region_columns_minus1;
e["ats_num_region_rows_minus_1"] = enhanced_.num_region_rows_minus1;
e["ats_num_region_columns_minus_1"] = enhanced_.num_region_columns_minus_1;
e["ats_num_region_rows_minus_1"] = enhanced_.num_region_rows_minus_1;
e["ats_uniform_spacing_flag"] = enhanced_.uniform_spacing_flag;
if (!enhanced_.uniform_spacing_flag) {
e["ats_column_width_minus_1"] = enhanced_.column_width_minus1;
e["ats_row_height_minus_1"] = enhanced_.row_height_minus1;
e["ats_column_width_minus_1"] = enhanced_.column_width_minus_1;
e["ats_row_height_minus_1"] = enhanced_.row_height_minus_1;
} else {
e["ats_region_width_minus_1"] = enhanced_.region_width_minus1;
e["ats_region_height_minus_1"] = enhanced_.region_height_minus1;
e["ats_region_width_minus_1"] = enhanced_.region_width_minus_1;
e["ats_region_height_minus_1"] = enhanced_.region_height_minus_1;
}
e["ats_single_region_per_atlas_segment_flag"] = enhanced_.single_region_per_segment_flag;
e["ats_num_atlas_segments_minus_1"] = enhanced_.num_atlas_segments_minus1;
e["ats_num_atlas_segments_minus_1"] = enhanced_.num_atlas_segments_minus_1;
if (!enhanced_.single_region_per_segment_flag) {
json regions = json::array();
for (const auto& r : enhanced_.segment_regions) {
Expand Down Expand Up @@ -237,8 +237,8 @@ json AtlasSegmentOBU::to_json() const {
break;
}
case ModeIdc::SINGLE_ATLAS:
j["ats_nominal_width_minus_1"] = nominal_width_minus1_;
j["ats_nominal_height_minus_1"] = nominal_height_minus1_;
j["ats_nominal_width_minus_1"] = nominal_width_minus_1_;
j["ats_nominal_height_minus_1"] = nominal_height_minus_1_;
break;
case ModeIdc::MULTISTREAM_ATLAS:
case ModeIdc::MULTISTREAM_ALPHA_ATLAS: {
Expand Down
34 changes: 17 additions & 17 deletions src/obus/metadata_unit.cpp
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Expand Up @@ -287,10 +287,10 @@ bool MetadataUnit::parse_payload(BitstreamReader& br) {
comp.banding_in_component_present_flag = static_cast<uint8_t>(br.read_bits(1));

if (comp.banding_in_component_present_flag) {
comp.max_band_width_minus4 = static_cast<uint8_t>(br.read_bits(6));
comp.max_band_step_minus1 = static_cast<uint8_t>(br.read_bits(4));
comp.max_band_width_minus_4 = static_cast<uint8_t>(br.read_bits(6));
comp.max_band_step_minus_1 = static_cast<uint8_t>(br.read_bits(4));
spdlog::debug(" component[{}]: present, width={}, step={}", plane,
comp.max_band_width_minus4, comp.max_band_step_minus1);
comp.max_band_width_minus_4, comp.max_band_step_minus_1);
} else {
spdlog::debug(" component[{}]: not present", plane);
}
Expand Down Expand Up @@ -320,22 +320,22 @@ bool MetadataUnit::parse_payload(BitstreamReader& br) {
int(band_block_in_luma_samples_));

// Read vertical sizes
vert_size_in_band_blocks_minus1_.clear();
vert_size_in_band_blocks_minus_1_.clear();
for (uint32_t r = 0; r <= num_band_units_rows_minus_1_; r++) {
uint8_t vert_size = static_cast<uint8_t>(br.read_bits(5));
vert_size_in_band_blocks_minus1_.push_back(vert_size);
vert_size_in_band_blocks_minus_1_.push_back(vert_size);
}

// Read horizontal sizes
horz_size_in_band_blocks_minus1_.clear();
horz_size_in_band_blocks_minus_1_.clear();
for (uint32_t c = 0; c <= num_band_units_cols_minus_1_; c++) {
uint8_t horz_size = static_cast<uint8_t>(br.read_bits(5));
horz_size_in_band_blocks_minus1_.push_back(horz_size);
horz_size_in_band_blocks_minus_1_.push_back(horz_size);
}

spdlog::debug(" Read {} vertical and {} horizontal band block sizes",
vert_size_in_band_blocks_minus1_.size(),
horz_size_in_band_blocks_minus1_.size());
vert_size_in_band_blocks_minus_1_.size(),
horz_size_in_band_blocks_minus_1_.size());
}

// Read banding flags for each band unit
Expand Down Expand Up @@ -593,17 +593,17 @@ void MetadataUnit::dump() const {
for (size_t i = 0; i < banding_components_.size(); i++) {
const auto& comp = banding_components_[i];
if (comp.banding_in_component_present_flag) {
spdlog::debug(" component[{}]: width={}, step={}", i, comp.max_band_width_minus4,
comp.max_band_step_minus1);
spdlog::debug(" component[{}]: width={}, step={}", i, comp.max_band_width_minus_4,
comp.max_band_step_minus_1);
}
}
if (band_units_information_present_flag_) {
spdlog::debug(" band_units: {} rows x {} cols", num_band_units_rows_minus_1_ + 1,
num_band_units_cols_minus_1_ + 1);
if (varying_size_band_units_flag_) {
spdlog::debug(" varying_size with {} vertical and {} horizontal sizes",
vert_size_in_band_blocks_minus1_.size(),
horz_size_in_band_blocks_minus1_.size());
vert_size_in_band_blocks_minus_1_.size(),
horz_size_in_band_blocks_minus_1_.size());
}
}
}
Expand Down Expand Up @@ -785,8 +785,8 @@ nlohmann::ordered_json MetadataUnit::to_json() const {
comp_json["banding_in_component_present_flag"] =
comp.banding_in_component_present_flag;
if (comp.banding_in_component_present_flag) {
comp_json["max_band_width_minus4"] = comp.max_band_width_minus4;
comp_json["max_band_step_minus1"] = comp.max_band_step_minus1;
comp_json["max_band_width_minus_4"] = comp.max_band_width_minus_4;
comp_json["max_band_step_minus_1"] = comp.max_band_step_minus_1;
}
components.push_back(comp_json);
}
Expand All @@ -801,8 +801,8 @@ nlohmann::ordered_json MetadataUnit::to_json() const {

if (varying_size_band_units_flag_) {
j["band_block_in_luma_samples"] = band_block_in_luma_samples_;
j["vert_size_in_band_blocks_minus1"] = vert_size_in_band_blocks_minus1_;
j["horz_size_in_band_blocks_minus1"] = horz_size_in_band_blocks_minus1_;
j["vert_size_in_band_blocks_minus_1"] = vert_size_in_band_blocks_minus_1_;
j["horz_size_in_band_blocks_minus_1"] = horz_size_in_band_blocks_minus_1_;
}

// Serialize 2D banding flags array
Expand Down
4 changes: 2 additions & 2 deletions src/obus/msdo_obu.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -28,8 +28,8 @@ bool MSDOOBU::parse_payload(std::ifstream& ifs) {
BitstreamReader br(raw_payload_);

// multistream_decoder_operation_obu()
uint32_t num_streams_minus2 = br.read_bits(3);
num_streams_ = num_streams_minus2 + 2;
uint32_t num_streams_minus_2 = br.read_bits(3);
num_streams_ = num_streams_minus_2 + 2;
multistream_profile_idc_ = br.read_bits(5);
multistream_level_idx_ = br.read_bits(5);
multistream_tier_ = br.read_bit();
Expand Down
4 changes: 2 additions & 2 deletions src/obus/multi_frame_header_obu.cpp
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Expand Up @@ -29,8 +29,8 @@ bool MultiFrameHeaderOBU::parse_payload(std::ifstream& ifs) {

// multi_frame_header_obu() syntax
mfh_seq_header_id_ = br.read_uvlc();
uint32_t mfh_id_minus1 = br.read_uvlc();
mfh_id_ = mfh_id_minus1 + 1;
uint32_t mfh_id_minus_1 = br.read_uvlc();
mfh_id_ = mfh_id_minus_1 + 1;

// Optional frame size override
mfh_frame_size_present_flag_ = br.read_bit();
Expand Down