LibVideo: Parameterize inter mode parsing in the VP9 decoder

Userland/Libraries/LibVideo/VP9/Parser.cpp

@@ -1217,7 +1217,7 @@ DecoderErrorOr<void> Parser::inter_block_mode_info()
     if (seg_feature_active(SEG_LVL_SKIP)) {
         m_y_mode = PredictionMode::ZeroMv;
     } else if (m_mi_size >= Block_8x8) {
-        m_y_mode = TRY_READ(m_tree_parser->parse_tree<PredictionMode>(SyntaxElementType::InterMode));
+        m_y_mode = TRY_READ(TreeParser::parse_inter_mode(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, m_mode_context[m_ref_frame[0]]));
     }
     if (m_interpolation_filter == Switchable)
         m_interp_filter = TRY_READ(m_tree_parser->parse_tree<InterpolationFilter>(SyntaxElementType::InterpFilter));
@@ -1228,7 +1228,7 @@ DecoderErrorOr<void> Parser::inter_block_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_y_mode = TRY_READ(m_tree_parser->parse_tree<PredictionMode>(SyntaxElementType::InterMode));
+                m_y_mode = TRY_READ(TreeParser::parse_inter_mode(*m_bit_stream, *m_probability_tables, *m_syntax_element_counter, m_mode_context[m_ref_frame[0]]));
                 if (m_y_mode == PredictionMode::NearestMv || m_y_mode == PredictionMode::NearMv) {
                     for (auto j = 0; j < 1 + is_compound; j++)
                         append_sub8x8_mvs(idy * 2 + idx, j);

Userland/Libraries/LibVideo/VP9/TreeParser.cpp

@@ -187,6 +187,19 @@ ErrorOr<PredictionMode> TreeParser::parse_uv_mode(BitStream& bit_stream, Probabi
     return value;
 }
 
+ErrorOr<PredictionMode> TreeParser::parse_inter_mode(BitStream& bit_stream, ProbabilityTables const& probability_table, SyntaxElementCounter& counter, u8 mode_context_for_ref_frame_0)
+{
+    // Tree
+    TreeParser::TreeSelection tree = { inter_mode_tree };
+
+    // Probabilities
+    u8 const* probabilities = probability_table.inter_mode_probs()[mode_context_for_ref_frame_0];
+
+    auto value = TRY(parse_tree_new<PredictionMode>(bit_stream, tree, [&](u8 node) { return probabilities[node]; }));
+    increment_counter(counter.m_counts_inter_mode[mode_context_for_ref_frame_0][to_underlying(value) - to_underlying(PredictionMode::NearestMv)]);
+    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
  */
@@ -213,8 +226,6 @@ TreeParser::TreeSelection TreeParser::select_tree(SyntaxElementType type)
         if (m_decoder.m_max_tx_size == TX_16x16)
             return { tx_size_16_tree };
         return { tx_size_8_tree };
-    case SyntaxElementType::InterMode:
-        return { inter_mode_tree };
     case SyntaxElementType::InterpFilter:
         return { interp_filter_tree };
     case SyntaxElementType::MVJoint:
@@ -268,8 +279,6 @@ u8 TreeParser::select_tree_probability(SyntaxElementType type, u8 node)
         return m_decoder.m_probability_tables->mv_bits_prob()[m_mv_component][m_mv_bit];
     case SyntaxElementType::TXSize:
         return calculate_tx_size_probability(node);
-    case SyntaxElementType::InterMode:
-        return calculate_inter_mode_probability(node);
     case SyntaxElementType::InterpFilter:
         return calculate_interp_filter_probability(node);
     case SyntaxElementType::MVJoint:
@@ -610,12 +619,6 @@ u8 TreeParser::calculate_tx_size_probability(u8 node)
     return m_decoder.m_probability_tables->tx_probs()[m_decoder.m_max_tx_size][m_ctx][node];
 }
 
-u8 TreeParser::calculate_inter_mode_probability(u8 node)
-{
-    m_ctx = m_decoder.m_mode_context[m_decoder.m_ref_frame[0]];
-    return m_decoder.m_probability_tables->inter_mode_probs()[m_ctx][node];
-}
-
 u8 TreeParser::calculate_interp_filter_probability(u8 node)
 {
     // NOTE: SWITCHABLE_FILTERS is not used in the spec for this function. Therefore, the number
@@ -747,9 +750,6 @@ void TreeParser::count_syntax_element(SyntaxElementType type, int value)
     case SyntaxElementType::TXSize:
         increment(m_decoder.m_syntax_element_counter->m_counts_tx_size[m_decoder.m_max_tx_size][m_ctx][value]);
         return;
-    case SyntaxElementType::InterMode:
-        increment(m_decoder.m_syntax_element_counter->m_counts_inter_mode[m_ctx][value]);
-        return;
     case SyntaxElementType::InterpFilter:
         increment(m_decoder.m_syntax_element_counter->m_counts_interp_filter[m_ctx][value]);
         return;

Userland/Libraries/LibVideo/VP9/TreeParser.h

@@ -68,6 +68,7 @@ public:
     static ErrorOr<PredictionMode> parse_intra_mode(BitStream&, ProbabilityTables const&, SyntaxElementCounter&, BlockSubsize mi_size);
     static ErrorOr<PredictionMode> parse_sub_intra_mode(BitStream&, ProbabilityTables const&, SyntaxElementCounter&);
     static ErrorOr<PredictionMode> parse_uv_mode(BitStream&, ProbabilityTables const&, SyntaxElementCounter&, PredictionMode y_mode);
+    static ErrorOr<PredictionMode> parse_inter_mode(BitStream&, ProbabilityTables const&, SyntaxElementCounter&, u8 mode_context_for_ref_frame_0);
 
     void set_default_intra_mode_variables(u8 idx, u8 idy)
     {
@@ -110,7 +111,6 @@ private:
     u8 calculate_single_ref_p1_probability();
     u8 calculate_single_ref_p2_probability();
     u8 calculate_tx_size_probability(u8 node);
-    u8 calculate_inter_mode_probability(u8 node);
     u8 calculate_interp_filter_probability(u8 node);
     u8 calculate_token_probability(u8 node);
     u8 calculate_more_coefs_probability();