Add a Vp9Parser implementation

media/filters/vp9_parser.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// This file contains an implementation of a VP9 bitstream parser. The main
+// purpose of this parser is to support hardware decode acceleration. Some
+// accelerators, e.g. libva which implements VA-API, require the caller
+// (chrome) to feed them parsed VP9 frame header.
+//
+// Example usage:
+//   {
+//     Vp9Parser parser;
+//     uint8_t* frame_stream;
+//     size_t frame_size;
+//
+//     // Get frames from, say, WebM parser or IVF parser.
+//     while (GetVp9Frame(&frame_stream, &frame_size)) {
+//       Vp9FrameHeader header;
+//       if (!parser.ParseFrame(frame_stream, frame_size, &header)) {
+//         // Parse failed.
+//         return false;
+//       }
+//       // Got a frame parsed successfully.
+//     }
+//  }
+
+#ifndef MEDIA_FILTERS_VP9_PARSER_H_
+#define MEDIA_FILTERS_VP9_PARSER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "base/macros.h"
+#include "media/base/media_export.h"
+#include "media/filters/vp9_raw_bits_reader.h"
+
+namespace media {
+
+const int kVp9MaxProfile = 4;
+const int kVp9NumRefFramesLog2 = 3;
+const int kVp9NumRefFrames = 1 << kVp9NumRefFramesLog2;
+const uint8_t kVp9MaxProb = 255;
+const int kVp9NumRefsPerFrame = 3;
+
+enum class Vp9ColorSpace {
+  UNKNOWN = 0,
+  BT_601 = 1,
+  BT_709 = 2,
+  SMPTE_170 = 3,
+  SMPTE_240 = 4,
+  BT_2020 = 5,
+  RESERVED = 6,
+  SRGB = 7,
+};
+
+enum class Vp9InterpFilter {
+  INTERP_FILTER_SELECT = 0,
+  EIGHTTAP_SMOOTH = 1,
+  EIGHTTAP = 2,
+  EIGHTTAP_SHARP = 3,
+  BILINEAR = 4,
+};
+
+// Members of Vp9FrameHeader will be 0-initialized by Vp9Parser::ParseFrame.
+struct MEDIA_EXPORT Vp9Segmentation {
+  static const int kNumSegments = 8;
+  static const int kNumTreeProbs = kNumSegments - 1;
+  static const int kNumPredictionProbs = 3;
+  static const int kNumFeatures = 4;
+
+  bool enabled;
+
+  bool update_map;
+  uint8_t tree_probs[kNumTreeProbs];
+  bool temporal_update;
+  uint8_t pred_probs[kNumPredictionProbs];
+
+  bool update_data;
+  bool abs_delta;
+  bool feature_enabled[kNumSegments][kNumFeatures];
+  int8_t feature_data[kNumSegments][kNumFeatures];
+};
+
+// Members of Vp9FrameHeader will be 0-initialized by Vp9Parser::ParseFrame.
+struct MEDIA_EXPORT Vp9LoopFilter {
+  static const int kNumRefDeltas = 4;
+  static const int kNumModeDeltas = 2;
+
+  uint8_t filter_level;
+  uint8_t sharpness_level;
+
+  bool mode_ref_delta_enabled;
+  bool mode_ref_delta_update;
+  bool update_ref_deltas[kNumRefDeltas];
+  int8_t ref_deltas[kNumRefDeltas];
+  bool update_mode_deltas[kNumModeDeltas];
+  int8_t mode_deltas[kNumModeDeltas];
+};
+
+// Members of Vp9FrameHeader will be 0-initialized by Vp9Parser::ParseFrame.
+struct MEDIA_EXPORT Vp9QuantizationParams {
+  bool IsLossless() const {
+    return base_qindex == 0 && y_dc_delta == 0 && uv_dc_delta == 0 &&
+           uv_ac_delta == 0;
+  }
+
+  uint8_t base_qindex;
+  int8_t y_dc_delta;
+  int8_t uv_dc_delta;
+  int8_t uv_ac_delta;
+};
+
+// VP9 frame header.
+struct MEDIA_EXPORT Vp9FrameHeader {
+  enum FrameType {
+    KEYFRAME = 0,
+    INTERFRAME = 1,
+  };
+
+  bool IsKeyframe() const { return frame_type == KEYFRAME; }
+
+  uint8_t profile;
+
+  bool show_existing_frame;
+  uint8_t frame_to_show;
+
+  FrameType frame_type;
+
+  bool show_frame;
+  bool error_resilient_mode;
+
+  uint8_t bit_depth;
+  Vp9ColorSpace color_space;
+  bool yuv_range;
+  uint8_t subsampling_x;
+  uint8_t subsampling_y;
+
+  // The range of width and height is 1..2^16.
+  uint32_t width;
+  uint32_t height;
+  uint32_t display_width;
+  uint32_t display_height;
+
+  bool intra_only;
+  uint8_t reset_context;
+  bool refresh_flag[kVp9NumRefFrames];
+  uint8_t frame_refs[kVp9NumRefsPerFrame];
+  bool ref_sign_biases[kVp9NumRefsPerFrame];
+  bool allow_high_precision_mv;
+  Vp9InterpFilter interp_filter;
+
+  bool refresh_frame_context;
+  bool frame_parallel_decoding_mode;
+  uint8_t frame_context_idx;
+
+  Vp9LoopFilter loop_filter;
+  Vp9QuantizationParams quant_params;
+  Vp9Segmentation segment;
+
+  uint8_t log2_tile_cols;
+  uint8_t log2_tile_rows;
+
+  // Size of compressed header in bytes.
+  size_t first_partition_size;
+
+  // Size of uncompressed header in bytes.
+  size_t uncompressed_header_size;
+};
+
+// A parser for VP9 bitstream.
+class MEDIA_EXPORT Vp9Parser {
+ public:
+  Vp9Parser();
+
+  // Parses one frame and fills parsing result to |fhdr|. Returns true on
+  // success, false otherwise.
+  // |stream| is the address of VP9 bitstream with |size|.
+  bool ParseFrame(const uint8_t* stream, size_t size, Vp9FrameHeader* fhdr);
+
+ private:
+  // The parsing context to keep track of references.
+  struct ReferenceSlot {
+    uint32_t width;
+    uint32_t height;
+  };
+
+  uint8_t ReadProfile();
+  bool VerifySyncCode();
+  bool ReadBitDepthColorSpaceSampling(Vp9FrameHeader* fhdr);
+  void ReadFrameSize(Vp9FrameHeader* fhdr);
+  bool ReadFrameSizeFromRefs(Vp9FrameHeader* fhdr);
+  void ReadDisplayFrameSize(Vp9FrameHeader* fhdr);
+  Vp9InterpFilter ReadInterpFilter();
+  void ReadLoopFilter(Vp9LoopFilter* loop_filter);
+  void ReadQuantization(Vp9QuantizationParams* quants);
+  void ReadSegmentationMap(Vp9Segmentation* segment);
+  void ReadSegmentationData(Vp9Segmentation* segment);
+  void ReadSegmentation(Vp9Segmentation* segment);
+  void ReadTiles(Vp9FrameHeader* fhdr);
+  bool ParseUncompressedHeader(Vp9FrameHeader* fhdr);
+  void UpdateSlots(const Vp9FrameHeader* fhdr);
+
+  // Start address of VP9 bitstream buffer.
+  const uint8_t* stream_;
+
+  // Size of |stream_| in bytes.
+  size_t size_;
+
+  // Raw bits decoder for uncompressed frame header.
+  Vp9RawBitsReader reader_;
+
+  // The parsing context to keep track of references.
+  ReferenceSlot ref_slots_[kVp9NumRefFrames];
+
+  DISALLOW_COPY_AND_ASSIGN(Vp9Parser);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_VP9_PARSER_H_