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// Copyright (c) 2016 The WebM project authors. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
#ifndef LIBWEBM_COMMON_VP9_HEADER_PARSER_H_
#define LIBWEBM_COMMON_VP9_HEADER_PARSER_H_
#include <stddef.h>
#include <stdint.h>
namespace vp9_parser {
const int kVp9FrameMarker = 2;
const int kMinTileWidthB64 = 4;
const int kMaxTileWidthB64 = 64;
const int kRefFrames = 8;
const int kRefsPerFrame = 3;
const int kRefFrames_LOG2 = 3;
const int kVpxCsBt601 = 1;
const int kVpxCsSrgb = 7;
const int kVpxCrStudioRange = 0;
const int kVpxCrFullRange = 1;
const int kMiSizeLog2 = 3;
// Class to parse the header of a VP9 frame.
class Vp9HeaderParser {
public:
Vp9HeaderParser()
: frame_(NULL),
frame_size_(0),
bit_offset_(0),
profile_(-1),
show_existing_frame_(0),
key_(0),
altref_(0),
error_resilient_mode_(0),
intra_only_(0),
reset_frame_context_(0),
bit_depth_(0),
color_space_(0),
color_range_(0),
subsampling_x_(0),
subsampling_y_(0),
refresh_frame_flags_(0),
width_(0),
height_(0),
row_tiles_(0),
column_tiles_(0),
frame_parallel_mode_(0) {}
// Parse the VP9 uncompressed header. The return values of the remaining
// functions are only valid on success.
bool ParseUncompressedHeader(const uint8_t* frame, size_t length);
size_t frame_size() const { return frame_size_; }
int profile() const { return profile_; }
int key() const { return key_; }
int altref() const { return altref_; }
int error_resilient_mode() const { return error_resilient_mode_; }
int bit_depth() const { return bit_depth_; }
int color_space() const { return color_space_; }
int width() const { return width_; }
int height() const { return height_; }
int refresh_frame_flags() const { return refresh_frame_flags_; }
int row_tiles() const { return row_tiles_; }
int column_tiles() const { return column_tiles_; }
int frame_parallel_mode() const { return frame_parallel_mode_; }
private:
// Set the compressed VP9 frame.
bool SetFrame(const uint8_t* frame, size_t length);
// Returns the next bit of the frame.
int ReadBit();
// Returns the next |bits| of the frame.
int VpxReadLiteral(int bits);
// Returns true if the vp9 sync code is valid.
bool ValidateVp9SyncCode();
// Parses bit_depth_, color_space_, subsampling_x_, subsampling_y_, and
// color_range_.
void ParseColorSpace();
// Parses width and height of the frame.
void ParseFrameResolution();
// Parses frame_parallel_mode_. This function skips over some features.
void ParseFrameParallelMode();
// Parses row and column tiles. This function skips over some features.
void ParseTileInfo();
void SkipDeltaQ();
int AlignPowerOfTwo(int value, int n);
const uint8_t* frame_;
size_t frame_size_;
size_t bit_offset_;
int profile_;
int show_existing_frame_;
int key_;
int altref_;
int error_resilient_mode_;
int intra_only_;
int reset_frame_context_;
int bit_depth_;
int color_space_;
int color_range_;
int subsampling_x_;
int subsampling_y_;
int refresh_frame_flags_;
int width_;
int height_;
int row_tiles_;
int column_tiles_;
int frame_parallel_mode_;
};
} // namespace vp9_parser
#endif // LIBWEBM_COMMON_VP9_HEADER_PARSER_H_
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