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-rw-r--r--Userland/Libraries/LibVideo/VP9/Context.h20
-rw-r--r--Userland/Libraries/LibVideo/VP9/Decoder.cpp46
-rw-r--r--Userland/Libraries/LibVideo/VP9/Decoder.h6
-rw-r--r--Userland/Libraries/LibVideo/VP9/Enums.h4
-rw-r--r--Userland/Libraries/LibVideo/VP9/Parser.cpp95
-rw-r--r--Userland/Libraries/LibVideo/VP9/Parser.h3
6 files changed, 104 insertions, 70 deletions
diff --git a/Userland/Libraries/LibVideo/VP9/Context.h b/Userland/Libraries/LibVideo/VP9/Context.h
index 7e2477d9cc..c543fb3d4f 100644
--- a/Userland/Libraries/LibVideo/VP9/Context.h
+++ b/Userland/Libraries/LibVideo/VP9/Context.h
@@ -32,6 +32,14 @@ enum class FrameShowMode {
DoNotShowFrame,
};
+struct Quantizers {
+ u16 y_ac_quantizer { 0 };
+ u16 uv_ac_quantizer { 0 };
+
+ u16 y_dc_quantizer { 0 };
+ u16 uv_dc_quantizer { 0 };
+};
+
struct FrameContext {
public:
static ErrorOr<FrameContext> create(ReadonlyBytes data,
@@ -126,15 +134,9 @@ public:
Array<i8, MAX_REF_FRAMES> loop_filter_reference_deltas;
Array<i8, 2> loop_filter_mode_deltas;
- u8 base_quantizer_index { 0 };
- i8 y_dc_quantizer_index_delta { 0 };
- i8 uv_dc_quantizer_index_delta { 0 };
- i8 uv_ac_quantizer_index_delta { 0 };
- bool is_lossless() const
- {
- // From quantization_params( ) in the spec.
- return base_quantizer_index == 0 && y_dc_quantizer_index_delta == 0 && uv_dc_quantizer_index_delta == 0 && uv_ac_quantizer_index_delta == 0;
- }
+ // Set based on quantization_params( ) in the spec.
+ bool lossless { false };
+ Array<Quantizers, MAX_SEGMENTS> segment_quantizers;
bool segmentation_enabled { false };
// Note: We can use Optional<Array<...>> for these tree probabilities, but unfortunately it seems to have measurable performance overhead.
diff --git a/Userland/Libraries/LibVideo/VP9/Decoder.cpp b/Userland/Libraries/LibVideo/VP9/Decoder.cpp
index 3756e12404..b8f3fa4ad1 100644
--- a/Userland/Libraries/LibVideo/VP9/Decoder.cpp
+++ b/Userland/Libraries/LibVideo/VP9/Decoder.cpp
@@ -1169,18 +1169,17 @@ inline u16 ac_q(u8 bit_depth, u8 b)
return ac_qlookup[(bit_depth - 8) >> 1][clip_3<u8>(0, 255, b)];
}
-u8 Decoder::get_base_quantizer_index(BlockContext const& block_context)
+u8 Decoder::get_base_quantizer_index(SegmentFeatureStatus alternative_quantizer_feature, bool should_use_absolute_segment_base_quantizer, u8 base_quantizer_index)
{
// The function get_qindex( ) returns the quantizer index for the current block and is specified by the following:
// − If seg_feature_active( SEG_LVL_ALT_Q ) is equal to 1 the following ordered steps apply:
- auto alternative_quantizer_feature = block_context.get_segment_feature(SegmentFeature::UseAlternativeQuantizerBase);
if (alternative_quantizer_feature.enabled) {
// 1. Set the variable data equal to FeatureData[ segment_id ][ SEG_LVL_ALT_Q ].
auto data = alternative_quantizer_feature.value;
// 2. If segmentation_abs_or_delta_update is equal to 0, set data equal to base_q_idx + data
- if (!block_context.frame_context.should_use_absolute_segment_base_quantizer) {
- data += block_context.frame_context.base_quantizer_index;
+ if (!should_use_absolute_segment_base_quantizer) {
+ data += base_quantizer_index;
}
// 3. Return Clip3( 0, 255, data ).
@@ -1188,33 +1187,29 @@ u8 Decoder::get_base_quantizer_index(BlockContext const& block_context)
}
// − Otherwise, return base_q_idx.
- return block_context.frame_context.base_quantizer_index;
+ return base_quantizer_index;
}
-u16 Decoder::get_dc_quantizer(BlockContext const& block_context, u8 plane)
+u16 Decoder::get_dc_quantizer(u8 bit_depth, u8 base, i8 delta)
{
- // FIXME: The result of this function can be cached. This does not change per frame.
+ // NOTE: Delta is selected by the caller based on whether it is for the Y or UV planes.
// The function get_dc_quant( plane ) returns the quantizer value for the dc coefficient for a particular plane and
// is derived as follows:
// − If plane is equal to 0, return dc_q( get_qindex( ) + delta_q_y_dc ).
// − Otherwise, return dc_q( get_qindex( ) + delta_q_uv_dc ).
- // Instead of if { return }, select the value to add and return.
- i8 offset = plane == 0 ? block_context.frame_context.y_dc_quantizer_index_delta : block_context.frame_context.uv_dc_quantizer_index_delta;
- return dc_q(block_context.frame_context.color_config.bit_depth, static_cast<u8>(get_base_quantizer_index(block_context) + offset));
+ return dc_q(bit_depth, static_cast<u8>(base + delta));
}
-u16 Decoder::get_ac_quantizer(BlockContext const& block_context, u8 plane)
+u16 Decoder::get_ac_quantizer(u8 bit_depth, u8 base, i8 delta)
{
- // FIXME: The result of this function can be cached. This does not change per frame.
+ // NOTE: Delta is selected by the caller based on whether it is for the Y or UV planes.
// The function get_ac_quant( plane ) returns the quantizer value for the ac coefficient for a particular plane and
// is derived as follows:
// − If plane is equal to 0, return ac_q( get_qindex( ) ).
// − Otherwise, return ac_q( get_qindex( ) + delta_q_uv_ac ).
- // Instead of if { return }, select the value to add and return.
- i8 offset = plane == 0 ? 0 : block_context.frame_context.uv_ac_quantizer_index_delta;
- return ac_q(block_context.frame_context.color_config.bit_depth, static_cast<u8>(get_base_quantizer_index(block_context) + offset));
+ return ac_q(bit_depth, static_cast<u8>(base + delta));
}
DecoderErrorOr<void> Decoder::reconstruct(u8 plane, BlockContext const& block_context, u32 transform_block_x, u32 transform_block_y, TransformSize transform_block_size, TransformSet transform_set)
@@ -1254,18 +1249,15 @@ DecoderErrorOr<void> Decoder::reconstruct_templated(u8 plane, BlockContext const
// 1. Dequant[ i ][ j ] is set equal to ( Tokens[ i * n0 + j ] * get_ac_quant( plane ) ) / dqDenom
// for i = 0..(n0-1), for j = 0..(n0-1)
Array<Intermediate, block_size * block_size> dequantized;
- Intermediate ac_quant = get_ac_quantizer(block_context, plane);
- for (auto i = 0u; i < block_size; i++) {
- for (auto j = 0u; j < block_size; j++) {
- auto index = i * block_size + j;
- if (index == 0)
- continue;
- dequantized[index] = (block_context.residual_tokens[index] * ac_quant) / dq_denominator;
- }
+ auto quantizers = block_context.frame_context.segment_quantizers[block_context.segment_id];
+ Intermediate ac_quant = plane == 0 ? quantizers.y_ac_quantizer : quantizers.uv_ac_quantizer;
+ auto const* tokens_raw = block_context.residual_tokens.data();
+ for (u32 i = 0; i < dequantized.size(); i++) {
+ dequantized[i] = (tokens_raw[i] * ac_quant) / dq_denominator;
}
// 2. Dequant[ 0 ][ 0 ] is set equal to ( Tokens[ 0 ] * get_dc_quant( plane ) ) / dqDenom
- dequantized[0] = (block_context.residual_tokens[0] * get_dc_quantizer(block_context, plane)) / dq_denominator;
+ dequantized[0] = (block_context.residual_tokens[0] * (plane == 0 ? quantizers.y_dc_quantizer : quantizers.uv_dc_quantizer)) / dq_denominator;
// It is a requirement of bitstream conformance that the values written into the Dequant array in steps 1 and 2
// are representable by a signed integer with 8 + BitDepth bits.
@@ -1819,7 +1811,7 @@ DecoderErrorOr<void> Decoder::inverse_transform_2d(BlockContext const& block_con
// 2. If Lossless is equal to 1, invoke the Inverse WHT process as specified in section 8.7.1.10 with shift equal
// to 2.
- if (block_context.frame_context.is_lossless()) {
+ if (block_context.frame_context.lossless) {
TRY(inverse_walsh_hadamard_transform(row, log2_of_block_size, 2));
continue;
}
@@ -1857,7 +1849,7 @@ DecoderErrorOr<void> Decoder::inverse_transform_2d(BlockContext const& block_con
// 2. If Lossless is equal to 1, invoke the Inverse WHT process as specified in section 8.7.1.10 with shift equal
// to 0.
- if (block_context.frame_context.is_lossless()) {
+ if (block_context.frame_context.lossless) {
TRY(inverse_walsh_hadamard_transform(column, log2_of_block_size, 2));
continue;
}
@@ -1885,7 +1877,7 @@ DecoderErrorOr<void> Decoder::inverse_transform_2d(BlockContext const& block_con
// 6. Otherwise (Lossless is equal to 0), set Dequant[ i ][ j ] equal to Round2( T[ i ], Min( 6, n + 2 ) )
// for i = 0..(n0-1).
- if (!block_context.frame_context.is_lossless()) {
+ if (!block_context.frame_context.lossless) {
for (auto i = 0u; i < block_size; i++) {
auto index = i * block_size + j;
dequantized[index] = rounded_right_shift(dequantized[index], min(6, log2_of_block_size + 2));
diff --git a/Userland/Libraries/LibVideo/VP9/Decoder.h b/Userland/Libraries/LibVideo/VP9/Decoder.h
index 9246fd504f..a043257ce2 100644
--- a/Userland/Libraries/LibVideo/VP9/Decoder.h
+++ b/Userland/Libraries/LibVideo/VP9/Decoder.h
@@ -73,11 +73,11 @@ private:
/* (8.6) Reconstruction and Dequantization */
// Returns the quantizer index for the current block
- static u8 get_base_quantizer_index(BlockContext const&);
+ static u8 get_base_quantizer_index(SegmentFeatureStatus alternative_quantizer_feature, bool should_use_absolute_segment_base_quantizer, u8 base_quantizer_index);
// Returns the quantizer value for the dc coefficient for a particular plane
- static u16 get_dc_quantizer(BlockContext const&, u8 plane);
+ static u16 get_dc_quantizer(u8 bit_depth, u8 base, i8 delta);
// Returns the quantizer value for the ac coefficient for a particular plane
- static u16 get_ac_quantizer(BlockContext const&, u8 plane);
+ static u16 get_ac_quantizer(u8 bit_depth, u8 base, i8 delta);
// (8.6.2) Reconstruct process
DecoderErrorOr<void> reconstruct(u8 plane, BlockContext const&, u32 transform_block_x, u32 transform_block_y, TransformSize transform_block_size, TransformSet);
diff --git a/Userland/Libraries/LibVideo/VP9/Enums.h b/Userland/Libraries/LibVideo/VP9/Enums.h
index e444803db5..3f59112e65 100644
--- a/Userland/Libraries/LibVideo/VP9/Enums.h
+++ b/Userland/Libraries/LibVideo/VP9/Enums.h
@@ -163,9 +163,9 @@ enum Token : u8 {
enum class SegmentFeature : u8 {
// SEG_LVL_ALT_Q
- UseAlternativeQuantizerBase,
+ AlternativeQuantizerBase,
// SEG_LVL_ALT_L
- UseAlternativeLoopFilterBase,
+ AlternativeLoopFilterBase,
// SEG_LVL_REF_FRAME
ReferenceFrameOverride,
// SEG_LVL_SKIP
diff --git a/Userland/Libraries/LibVideo/VP9/Parser.cpp b/Userland/Libraries/LibVideo/VP9/Parser.cpp
index 25b25c14ed..a6f9bc716c 100644
--- a/Userland/Libraries/LibVideo/VP9/Parser.cpp
+++ b/Userland/Libraries/LibVideo/VP9/Parser.cpp
@@ -143,6 +143,39 @@ DecoderErrorOr<VideoFullRangeFlag> Parser::read_video_full_range_flag(BigEndianI
return VideoFullRangeFlag::Studio;
}
+template<Signed T = i8>
+static ErrorOr<T> read_signed(BigEndianInputBitStream& bit_stream, u8 bits)
+{
+ auto value_unsigned = static_cast<T>(TRY(bit_stream.read_bits(bits)));
+ if (TRY(bit_stream.read_bit()))
+ return -value_unsigned;
+ return value_unsigned;
+}
+
+static DecoderErrorOr<i8> read_delta_q(BigEndianInputBitStream& bit_stream)
+{
+ if (TRY_READ(bit_stream.read_bit()))
+ return TRY_READ(read_signed(bit_stream, 4));
+ return 0;
+}
+
+struct QuantizationParameters {
+ u8 base_quantizer_index { 0 };
+ i8 y_dc_quantizer_index_delta { 0 };
+ i8 uv_dc_quantizer_index_delta { 0 };
+ i8 uv_ac_quantizer_index_delta { 0 };
+};
+
+static DecoderErrorOr<QuantizationParameters> quantization_params(BigEndianInputBitStream& bit_stream)
+{
+ QuantizationParameters result;
+ result.base_quantizer_index = TRY_READ(bit_stream.read_bits(8));
+ result.y_dc_quantizer_index_delta = TRY(read_delta_q(bit_stream));
+ result.uv_dc_quantizer_index_delta = TRY(read_delta_q(bit_stream));
+ result.uv_ac_quantizer_index_delta = TRY(read_delta_q(bit_stream));
+ return result;
+}
+
/* (6.2) */
DecoderErrorOr<void> Parser::uncompressed_header(FrameContext& frame_context)
{
@@ -266,8 +299,10 @@ DecoderErrorOr<void> Parser::uncompressed_header(FrameContext& frame_context)
frame_context.probability_context_index = probability_context_index;
TRY(loop_filter_params(frame_context));
- TRY(quantization_params(frame_context));
+ auto quantization_parameters = TRY(quantization_params(frame_context.bit_stream));
TRY(segmentation_params(frame_context));
+ precalculate_quantizers(frame_context, quantization_parameters);
+
TRY(parse_tile_counts(frame_context));
frame_context.header_size_in_bytes = TRY_READ(frame_context.bit_stream.read_bits(16));
@@ -399,15 +434,6 @@ DecoderErrorOr<InterpolationFilter> Parser::read_interpolation_filter(BigEndianI
return literal_to_type[TRY_READ(bit_stream.read_bits(2))];
}
-template<Signed T = i8>
-static ErrorOr<T> read_signed(BigEndianInputBitStream& bit_stream, u8 bits)
-{
- auto value_unsigned = static_cast<T>(TRY(bit_stream.read_bits(bits)));
- if (TRY(bit_stream.read_bit()))
- return -value_unsigned;
- return value_unsigned;
-}
-
DecoderErrorOr<void> Parser::loop_filter_params(FrameContext& frame_context)
{
// FIXME: These should be moved to their own struct to return here.
@@ -433,22 +459,6 @@ DecoderErrorOr<void> Parser::loop_filter_params(FrameContext& frame_context)
return {};
}
-DecoderErrorOr<void> Parser::quantization_params(FrameContext& frame_context)
-{
- frame_context.base_quantizer_index = TRY_READ(frame_context.bit_stream.read_bits(8));
- frame_context.y_dc_quantizer_index_delta = TRY(read_delta_q(frame_context.bit_stream));
- frame_context.uv_dc_quantizer_index_delta = TRY(read_delta_q(frame_context.bit_stream));
- frame_context.uv_ac_quantizer_index_delta = TRY(read_delta_q(frame_context.bit_stream));
- return {};
-}
-
-DecoderErrorOr<i8> Parser::read_delta_q(BigEndianInputBitStream& bit_stream)
-{
- if (TRY_READ(bit_stream.read_bit()))
- return TRY_READ(read_signed(bit_stream, 4));
- return 0;
-}
-
DecoderErrorOr<void> Parser::segmentation_params(FrameContext& frame_context)
{
frame_context.segmentation_enabled = TRY_READ(frame_context.bit_stream.read_bit());
@@ -501,6 +511,35 @@ DecoderErrorOr<u8> Parser::read_prob(BigEndianInputBitStream& bit_stream)
return 255;
}
+void Parser::precalculate_quantizers(FrameContext& frame_context, QuantizationParameters quantization_parameters)
+{
+ frame_context.lossless = quantization_parameters.base_quantizer_index == 0
+ && quantization_parameters.y_dc_quantizer_index_delta == 0
+ && quantization_parameters.uv_dc_quantizer_index_delta == 0
+ && quantization_parameters.uv_ac_quantizer_index_delta == 0;
+
+ // Pre-calculate the quantizers so that the decoder doesn't have to do it repeatedly.
+ for (u8 segment_id = 0; segment_id < MAX_SEGMENTS; segment_id++) {
+ auto alternative_quantizer_feature = frame_context.get_segment_feature(segment_id, SegmentFeature::AlternativeQuantizerBase);
+ auto base = Decoder::get_base_quantizer_index(alternative_quantizer_feature, frame_context.should_use_absolute_segment_base_quantizer, quantization_parameters.base_quantizer_index);
+
+ // The function get_ac_quant( plane ) returns the quantizer value for the ac coefficient for a particular plane and
+ // is derived as follows:
+ // − If plane is equal to 0, return ac_q( get_qindex( ) ).
+ // − Otherwise, return ac_q( get_qindex( ) + delta_q_uv_ac ).
+ auto& current_quantizers = frame_context.segment_quantizers[segment_id];
+ current_quantizers.y_ac_quantizer = Decoder::get_ac_quantizer(frame_context.color_config.bit_depth, base, 0);
+ current_quantizers.uv_ac_quantizer = Decoder::get_ac_quantizer(frame_context.color_config.bit_depth, base, quantization_parameters.uv_ac_quantizer_index_delta);
+
+ // The function get_dc_quant( plane ) returns the quantizer value for the dc coefficient for a particular plane and
+ // is derived as follows:
+ // − If plane is equal to 0, return dc_q( get_qindex( ) + delta_q_y_dc ).
+ // − Otherwise, return dc_q( get_qindex( ) + delta_q_uv_dc ).
+ current_quantizers.y_dc_quantizer = Decoder::get_dc_quantizer(frame_context.color_config.bit_depth, base, quantization_parameters.y_dc_quantizer_index_delta);
+ current_quantizers.uv_dc_quantizer = Decoder::get_dc_quantizer(frame_context.color_config.bit_depth, base, quantization_parameters.uv_dc_quantizer_index_delta);
+ }
+}
+
static u16 calc_min_log2_of_tile_columns(u32 superblock_columns)
{
auto min_log_2 = 0u;
@@ -577,7 +616,7 @@ DecoderErrorOr<void> Parser::compressed_header(FrameContext& frame_context)
DecoderErrorOr<TransformMode> Parser::read_tx_mode(BooleanDecoder& decoder, FrameContext const& frame_context)
{
- if (frame_context.is_lossless()) {
+ if (frame_context.lossless) {
return TransformMode::Only_4x4;
}
@@ -1373,7 +1412,7 @@ static TransformSet select_transform_type(BlockContext const& block_context, u8
if (plane > 0 || transform_size == Transform_32x32)
return TransformSet { TransformType::DCT, TransformType::DCT };
if (transform_size == Transform_4x4) {
- if (block_context.frame_context.is_lossless() || block_context.is_inter_predicted())
+ if (block_context.frame_context.lossless || block_context.is_inter_predicted())
return TransformSet { TransformType::DCT, TransformType::DCT };
return mode_to_txfm_map[to_underlying(block_context.size < Block_8x8 ? block_context.sub_block_prediction_modes[block_index] : block_context.y_prediction_mode())];
diff --git a/Userland/Libraries/LibVideo/VP9/Parser.h b/Userland/Libraries/LibVideo/VP9/Parser.h
index c29540fbe5..85b99e9075 100644
--- a/Userland/Libraries/LibVideo/VP9/Parser.h
+++ b/Userland/Libraries/LibVideo/VP9/Parser.h
@@ -30,6 +30,7 @@ struct FrameContext;
struct TileContext;
struct BlockContext;
struct MotionVectorCandidate;
+struct QuantizationParameters;
class Parser {
friend class TreeParser;
@@ -61,10 +62,10 @@ private:
DecoderErrorOr<void> compute_image_size(FrameContext&);
DecoderErrorOr<InterpolationFilter> read_interpolation_filter(BigEndianInputBitStream&);
DecoderErrorOr<void> loop_filter_params(FrameContext&);
- DecoderErrorOr<void> quantization_params(FrameContext&);
DecoderErrorOr<i8> read_delta_q(BigEndianInputBitStream&);
DecoderErrorOr<void> segmentation_params(FrameContext&);
DecoderErrorOr<u8> read_prob(BigEndianInputBitStream&);
+ static void precalculate_quantizers(FrameContext& frame_context, QuantizationParameters quantization_parameters);
DecoderErrorOr<void> parse_tile_counts(FrameContext&);
void setup_past_independence();