LibVideo/VP9: Move partitioning contexts to TileContext

Like the non-zero tokens and segmentation IDs, these can be moved into
the tile decoding loop for above context and allocated by TileContext
for left context.

Userland/Libraries/LibVideo/VP9/Context.h

@@ -75,8 +75,8 @@ public:
     }
     u32 rows() const { return m_rows; }
     u32 columns() const { return m_columns; }
-    u32 superblock_rows() const { return blocks_to_superblocks(rows() + 7u); }
-    u32 superblock_columns() const { return blocks_to_superblocks(columns() + 7u); }
+    u32 superblock_rows() const { return blocks_ceiled_to_superblocks(rows()); }
+    u32 superblock_columns() const { return blocks_ceiled_to_superblocks(columns()); }
 
     Vector2D<FrameBlockContext> const& block_contexts() const { return m_block_contexts; }
 
@@ -175,9 +175,11 @@ static NonZeroTokensView create_non_zero_tokens_view(NonZeroTokens& non_zero_tok
 
 struct TileContext {
 public:
-    static ErrorOr<TileContext> try_create(FrameContext& frame_context, u32 rows_start, u32 rows_end, u32 columns_start, u32 columns_end, NonZeroTokensView above_non_zero_tokens, SegmentationPredictionContextView above_segmentation_ids)
+    static ErrorOr<TileContext> try_create(FrameContext& frame_context, u32 rows_start, u32 rows_end, u32 columns_start, u32 columns_end, PartitionContextView above_partition_context, NonZeroTokensView above_non_zero_tokens, SegmentationPredictionContextView above_segmentation_ids)
     {
-        auto context_view = frame_context.m_block_contexts.view(rows_start, columns_start, rows_end - rows_start, columns_end - columns_start);
+        auto width = columns_end - columns_start;
+        auto height = rows_end - rows_start;
+        auto context_view = frame_context.m_block_contexts.view(rows_start, columns_start, height, width);
 
         return TileContext {
             frame_context,
@@ -186,10 +188,12 @@ public:
             columns_start,
             columns_end,
             context_view,
+            above_partition_context,
             above_non_zero_tokens,
             above_segmentation_ids,
-            TRY(create_non_zero_tokens(blocks_to_sub_blocks(rows_end - rows_start), frame_context.color_config.subsampling_y)),
-            TRY(SegmentationPredictionContext::try_create(rows_end - rows_start)),
+            TRY(PartitionContext::try_create(superblocks_to_blocks(blocks_ceiled_to_superblocks(height)))),
+            TRY(create_non_zero_tokens(blocks_to_sub_blocks(height), frame_context.color_config.subsampling_y)),
+            TRY(SegmentationPredictionContext::try_create(height)),
         };
     }
 
@@ -204,8 +208,10 @@ public:
     u32 columns() const { return columns_end - columns_start; }
     Vector2DView<FrameBlockContext> block_contexts_view;
 
+    PartitionContextView above_partition_context;
     NonZeroTokensView above_non_zero_tokens;
     SegmentationPredictionContextView above_segmentation_ids;
+    PartitionContext left_partition_context;
     NonZeroTokens left_non_zero_tokens;
     SegmentationPredictionContext left_segmentation_ids;
 };

Userland/Libraries/LibVideo/VP9/ContextStorage.h

@@ -254,4 +254,7 @@ using NonZeroTokensView = Array<Span<bool>, 3>;
 using SegmentationPredictionContext = FixedArray<u8>;
 using SegmentationPredictionContextView = Span<u8>;
 
+using PartitionContext = FixedArray<u8>;
+using PartitionContextView = Span<u8>;
+
 }

Userland/Libraries/LibVideo/VP9/Parser.cpp

@@ -849,7 +849,7 @@ DecoderErrorOr<void> Parser::decode_tiles(FrameContext& frame_context)
     auto tile_cols = 1 << log2_dimensions.width();
     auto tile_rows = 1 << log2_dimensions.height();
 
-    clear_above_context(frame_context);
+    PartitionContext above_partition_context = DECODER_TRY_ALLOC(PartitionContext::try_create(superblocks_to_blocks(frame_context.superblock_columns())));
     NonZeroTokens above_non_zero_tokens = DECODER_TRY_ALLOC(create_non_zero_tokens(blocks_to_sub_blocks(frame_context.columns()), frame_context.color_config.subsampling_x));
     SegmentationPredictionContext above_segmentation_ids = DECODER_TRY_ALLOC(SegmentationPredictionContext::try_create(frame_context.columns()));
 
@@ -860,7 +860,7 @@ DecoderErrorOr<void> Parser::decode_tiles(FrameContext& frame_context)
     for (auto tile_row = 0; tile_row < tile_rows; tile_row++) {
         for (auto tile_col = 0; tile_col < tile_cols; tile_col++) {
             auto last_tile = (tile_row == tile_rows - 1) && (tile_col == tile_cols - 1);
-            u64 tile_size;
+            size_t tile_size;
             if (last_tile)
                 tile_size = m_bit_stream->bytes_remaining();
             else
@@ -871,10 +871,12 @@ DecoderErrorOr<void> Parser::decode_tiles(FrameContext& frame_context)
             auto columns_start = get_tile_offset(tile_col, frame_context.columns(), log2_dimensions.width());
             auto columns_end = get_tile_offset(tile_col + 1, frame_context.columns(), log2_dimensions.width());
 
+            auto width = columns_end - columns_start;
+            auto above_partition_context_for_tile = above_partition_context.span().slice(columns_start, superblocks_to_blocks(blocks_ceiled_to_superblocks(width)));
             auto above_non_zero_tokens_view = create_non_zero_tokens_view(above_non_zero_tokens, blocks_to_sub_blocks(columns_start), blocks_to_sub_blocks(columns_end - columns_start), frame_context.color_config.subsampling_x);
             auto above_segmentation_ids_for_tile = safe_slice(above_segmentation_ids.span(), columns_start, columns_end - columns_start);
 
-            auto tile_context = DECODER_TRY_ALLOC(TileContext::try_create(frame_context, rows_start, rows_end, columns_start, columns_end, above_non_zero_tokens_view, above_segmentation_ids_for_tile));
+            auto tile_context = DECODER_TRY_ALLOC(TileContext::try_create(frame_context, rows_start, rows_end, columns_start, columns_end, above_partition_context_for_tile, above_non_zero_tokens_view, above_segmentation_ids_for_tile));
 
             TRY_READ(m_bit_stream->init_bool(tile_size));
             TRY(decode_tile(tile_context));
@@ -900,11 +902,6 @@ void Parser::clear_context(Vector<Vector<T>>& context, size_t outer_size, size_t
         clear_context(sub_vector, inner_size);
 }
 
-void Parser::clear_above_context(FrameContext& frame_context)
-{
-    clear_context(m_above_partition_context, frame_context.superblock_columns() * 8);
-}
-
 u32 Parser::get_tile_offset(u32 tile_num, u32 mis, u32 tile_size_log2)
 {
     u32 super_blocks = (mis + 7) >> 3u;
@@ -928,7 +925,7 @@ void Parser::clear_left_context(TileContext& tile_context)
     for (auto& context_for_plane : tile_context.left_non_zero_tokens)
         context_for_plane.fill_with(false);
     tile_context.left_segmentation_ids.fill_with(0);
-    clear_context(m_left_partition_context, tile_context.frame_context.superblock_rows() * 8);
+    tile_context.left_partition_context.fill_with(0);
 }
 
 DecoderErrorOr<void> Parser::decode_partition(TileContext& tile_context, u32 row, u32 column, BlockSubsize subsize)
@@ -939,7 +936,9 @@ DecoderErrorOr<void> Parser::decode_partition(TileContext& tile_context, u32 row
     auto half_block_8x8 = num_8x8 >> 1;
     bool has_rows = (row + half_block_8x8) < tile_context.frame_context.rows();
     bool has_cols = (column + half_block_8x8) < tile_context.frame_context.columns();
-    auto partition = TRY_READ(TreeParser::parse_partition(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, has_rows, has_cols, subsize, num_8x8, m_above_partition_context, m_left_partition_context, row, column, !tile_context.frame_context.is_inter_predicted()));
+    u32 row_in_tile = row - tile_context.rows_start;
+    u32 column_in_tile = column - tile_context.columns_start;
+    auto partition = TRY_READ(TreeParser::parse_partition(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, has_rows, has_cols, subsize, num_8x8, tile_context.above_partition_context, tile_context.left_partition_context.span(), row_in_tile, column_in_tile, !tile_context.frame_context.is_inter_predicted()));
 
     auto child_subsize = subsize_lookup[partition][subsize];
     if (child_subsize < Block_8x8 || partition == PartitionNone) {
@@ -962,8 +961,8 @@ DecoderErrorOr<void> Parser::decode_partition(TileContext& tile_context, u32 row
         auto above_context = 15 >> b_width_log2_lookup[child_subsize];
         auto left_context = 15 >> b_height_log2_lookup[child_subsize];
         for (size_t i = 0; i < num_8x8; i++) {
-            m_above_partition_context[column + i] = above_context;
-            m_left_partition_context[row + i] = left_context;
+            tile_context.above_partition_context[column_in_tile + i] = above_context;
+            tile_context.left_partition_context[row_in_tile + i] = left_context;
         }
     }
     return {};

Userland/Libraries/LibVideo/VP9/Parser.h

@@ -99,7 +99,6 @@ private:
 
     /* (6.4) Decode Tiles Syntax */
     DecoderErrorOr<void> decode_tiles(FrameContext&);
-    void clear_above_context(FrameContext&);
     u32 get_tile_offset(u32 tile_num, u32 mis, u32 tile_size_log2);
     DecoderErrorOr<void> decode_tile(TileContext&);
     void clear_left_context(TileContext&);
@@ -146,10 +145,6 @@ private:
     bool m_previous_should_use_absolute_segment_base_quantizer;
     Array<Array<SegmentFeature, SEG_LVL_MAX>, MAX_SEGMENTS> m_previous_segmentation_features;
 
-    // FIXME: Move above and left contexts to structs
-    Vector<u8> m_above_partition_context;
-    Vector<u8> m_left_partition_context;
-
     // FIXME: Move these to a struct to store together in one array.
     Gfx::Size<u32> m_ref_frame_size[NUM_REF_FRAMES];
     bool m_ref_subsampling_x[NUM_REF_FRAMES];

Userland/Libraries/LibVideo/VP9/TreeParser.cpp

@@ -44,7 +44,7 @@ inline void increment_counter(u8& counter)
     counter = min(static_cast<u32>(counter) + 1, 255);
 }
 
-ErrorOr<Partition> TreeParser::parse_partition(BitStream& bit_stream, ProbabilityTables const& probability_table, SyntaxElementCounter& counter, 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)
+ErrorOr<Partition> TreeParser::parse_partition(BitStream& bit_stream, ProbabilityTables const& probability_table, SyntaxElementCounter& counter, bool has_rows, bool has_columns, BlockSubsize block_subsize, u8 num_8x8, PartitionContextView above_partition_context, PartitionContextView left_partition_context, u32 row, u32 column, bool frame_is_intra)
 {
     // Tree array
     TreeParser::TreeSelection tree = { PartitionSplit };
@@ -61,7 +61,11 @@ ErrorOr<Partition> TreeParser::parse_partition(BitStream& bit_stream, Probabilit
     auto bsl = mi_width_log2_lookup[block_subsize];
     auto block_offset = mi_width_log2_lookup[Block_64x64] - bsl;
     for (auto i = 0; i < num_8x8; i++) {
+        if (column + i >= above_partition_context.size())
+            dbgln("column={}, i={}, size={}", column, i, above_partition_context.size());
         above |= above_partition_context[column + i];
+        if (row + i >= left_partition_context.size())
+            dbgln("row={}, i={}, size={}", row, i, left_partition_context.size());
         left |= left_partition_context[row + i];
     }
     above = (above & (1 << block_offset)) > 0;

Userland/Libraries/LibVideo/VP9/TreeParser.h

@@ -59,7 +59,7 @@ public:
         TreeSelectionValue m_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<Partition> parse_partition(BitStream&, ProbabilityTables const&, SyntaxElementCounter&, bool has_rows, bool has_columns, BlockSubsize block_subsize, u8 num_8x8, PartitionContextView above_partition_context, PartitionContextView left_partition_context, u32 row, u32 column, bool frame_is_intra);
     static ErrorOr<PredictionMode> parse_default_intra_mode(BitStream&, ProbabilityTables const&, BlockSubsize mi_size, FrameBlockContext above, FrameBlockContext left, Array<PredictionMode, 4> const& block_sub_modes, u8 index_x, u8 index_y);
     static ErrorOr<PredictionMode> parse_default_uv_mode(BitStream&, ProbabilityTables const&, PredictionMode y_mode);
     static ErrorOr<PredictionMode> parse_intra_mode(BitStream&, ProbabilityTables const&, SyntaxElementCounter&, BlockSubsize mi_size);

Userland/Libraries/LibVideo/VP9/Utilities.h

@@ -72,6 +72,12 @@ 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)
 {