ref: 34034789d758440415306a637e6aea57f34e1a4c
dir: /vp9/simple_encode.h/
/*
* Copyright (c) 2019 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 VPX_VP9_SIMPLE_ENCODE_H_
#define VPX_VP9_SIMPLE_ENCODE_H_
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <memory>
#include <vector>
namespace vp9 {
// TODO(angiebird): Add description for each frame type.
enum FrameType {
kFrameTypeKey = 0,
kFrameTypeInter,
kFrameTypeAltRef,
kFrameTypeOverlay,
kFrameTypeGolden,
};
// TODO(angiebird): Add description for each reference frame type.
// This enum numbers have to be contiguous and start from zero except
// kNoneRefFrame.
enum RefFrameType {
kRefFrameTypeLast = 0,
kRefFrameTypePast = 1,
kRefFrameTypeFuture = 2,
kRefFrameTypeMax = 3,
kRefFrameTypeNone = -1,
};
enum GopMapFlag {
kGopMapFlagStart =
1 << 0, // Indicate this location is the start of a group of pictures.
kGopMapFlagUseAltRef =
1 << 1, // Indicate this group of pictures will use an alt ref. Only set
// this flag when kGopMapFlagStart is set.
};
// The frame is split to 4x4 blocks.
// This structure contains the information of each 4x4 block.
struct PartitionInfo {
int row; // row pixel offset of current 4x4 block
int column; // column pixel offset of current 4x4 block
int row_start; // row pixel offset of the start of the prediction block
int column_start; // column pixel offset of the start of the prediction block
int width; // prediction block width
int height; // prediction block height
};
constexpr int kMotionVectorPrecision = 8;
// The frame is split to 4x4 blocks.
// This structure contains the information of each 4x4 block.
struct MotionVectorInfo {
// Number of valid motion vectors, always 0 if this block is in the key frame.
// For inter frames, it could be 1 or 2.
int mv_count;
// The reference frame for motion vectors. If the second motion vector does
// not exist (mv_count = 1), the reference frame is kNoneRefFrame.
// Otherwise, the reference frame is either kLastFrame, or kGoldenFrame,
// or kAltRefFrame.
RefFrameType ref_frame[2];
// The row offset of motion vectors in the unit of pixel.
// If the second motion vector does not exist, the value is 0.
double mv_row[2];
// The column offset of motion vectors in the unit of pixel.
// If the second motion vector does not exist, the value is 0.
double mv_column[2];
};
struct RefFrameInfo {
int coding_indexes[kRefFrameTypeMax];
// Indicate whether the reference frames are available or not.
// When the reference frame type is not valid, it means either the to-be-coded
// frame is a key frame or the reference frame already appears in other
// reference frame type. vp9 always keeps three types of reference frame
// available. However, the duplicated reference frames will not be
// chosen by the encoder. The priorities of choosing reference frames are
// kRefFrameTypeLast > kRefFrameTypePast > kRefFrameTypeFuture.
// For example, if kRefFrameTypeLast and kRefFrameTypePast both point to the
// same frame, kRefFrameTypePast will be set to invalid.
// 1: the ref frame type is available 0: the ref frame type is not available
int valid_list[kRefFrameTypeMax];
};
bool operator==(const RefFrameInfo &a, const RefFrameInfo &b);
struct EncodeFrameInfo {
int show_idx;
// Each show or no show frame is assigned with a coding index based on its
// coding order (starting from zero) in the coding process of the entire
// video. The coding index for each frame is unique.
int coding_index;
RefFrameInfo ref_frame_info;
FrameType frame_type;
};
// This structure is a copy of vp9 |nmv_component_counts|.
struct NewMotionvectorComponentCounts {
std::vector<unsigned int> sign;
std::vector<unsigned int> classes;
std::vector<unsigned int> class0;
std::vector<std::vector<unsigned int>> bits;
std::vector<std::vector<unsigned int>> class0_fp;
std::vector<unsigned int> fp;
std::vector<unsigned int> class0_hp;
std::vector<unsigned int> hp;
};
// This structure is a copy of vp9 |nmv_context_counts|.
struct NewMotionVectorContextCounts {
std::vector<unsigned int> joints;
std::vector<NewMotionvectorComponentCounts> comps;
};
using UintArray2D = std::vector<std::vector<unsigned int>>;
using UintArray3D = std::vector<std::vector<std::vector<unsigned int>>>;
using UintArray5D = std::vector<
std::vector<std::vector<std::vector<std::vector<unsigned int>>>>>;
using UintArray6D = std::vector<std::vector<
std::vector<std::vector<std::vector<std::vector<unsigned int>>>>>>;
// This structure is a copy of vp9 |tx_counts|.
struct TransformSizeCounts {
// Transform size found in blocks of partition size 32x32.
// First dimension: transform size contexts (2).
// Second dimension: transform size type (3: 32x32, 16x16, 8x8)
UintArray2D p32x32;
// Transform size found in blocks of partition size 16x16.
// First dimension: transform size contexts (2).
// Second dimension: transform size type (2: 16x16, 8x8)
UintArray2D p16x16;
// Transform size found in blocks of partition size 8x8.
// First dimension: transform size contexts (2).
// Second dimension: transform size type (1: 8x8)
UintArray2D p8x8;
// Overall transform size count.
std::vector<unsigned int> tx_totals;
};
// This structure is a copy of vp9 |FRAME_COUNTS|.
struct FrameCounts {
// Intra prediction mode for luma plane. First dimension: block size (4).
// Second dimension: intra prediction mode (10).
UintArray2D y_mode;
// Intra prediction mode for chroma plane. First and second dimension:
// intra prediction mode (10).
UintArray2D uv_mode;
// Partition type. First dimension: partition contexts (16).
// Second dimension: partition type (4).
UintArray2D partition;
// Transform coefficient.
UintArray6D coef;
// End of block (the position of the last non-zero transform coefficient)
UintArray5D eob_branch;
// Interpolation filter type. First dimension: switchable filter contexts (4).
// Second dimension: filter types (3).
UintArray2D switchable_interp;
// Inter prediction mode (the motion vector type).
// First dimension: inter mode contexts (7).
// Second dimension: mode type (4).
UintArray2D inter_mode;
// Block is intra or inter predicted. First dimension: contexts (4).
// Second dimension: type (0 for intra, 1 for inter).
UintArray2D intra_inter;
// Block is compound predicted (predicted from average of two blocks).
// First dimension: contexts (5).
// Second dimension: type (0 for single, 1 for compound prediction).
UintArray2D comp_inter;
// Type of the reference frame. Only one reference frame.
// First dimension: context (5). Second dimension: context (2).
// Third dimension: count (2).
UintArray3D single_ref;
// Type of the two reference frames.
// First dimension: context (5). Second dimension: count (2).
UintArray2D comp_ref;
// Block skips transform and quantization, uses prediction as reconstruction.
// First dimension: contexts (3). Second dimension: type (0 not skip, 1 skip).
UintArray2D skip;
// Transform size.
TransformSizeCounts tx;
// New motion vector.
NewMotionVectorContextCounts mv;
};
struct ImageBuffer {
// The image data is stored in raster order,
// i.e. image[plane][r][c] =
// plane_buffer[plane][r * plane_width[plane] + plane_height[plane]].
std::unique_ptr<unsigned char[]> plane_buffer[3];
int plane_width[3];
int plane_height[3];
};
void output_image_buffer(const ImageBuffer &image_buffer, std::FILE *out_file);
struct EncodeFrameResult {
int show_idx;
FrameType frame_type;
int coding_idx;
RefFrameInfo ref_frame_info;
size_t coding_data_bit_size;
size_t coding_data_byte_size;
// The EncodeFrame will allocate a buffer, write the coding data into the
// buffer and give the ownership of the buffer to coding_data.
std::unique_ptr<unsigned char[]> coding_data;
double psnr;
uint64_t sse;
int quantize_index;
FrameCounts frame_counts;
int num_rows_4x4; // number of row units, in size of 4.
int num_cols_4x4; // number of column units, in size of 4.
// A vector of the partition information of the frame.
// The number of elements is |num_rows_4x4| * |num_cols_4x4|.
// The frame is divided 4x4 blocks of |num_rows_4x4| rows and
// |num_cols_4x4| columns.
// Each 4x4 block contains the current pixel position (|row|, |column|),
// the start pixel position of the partition (|row_start|, |column_start|),
// and the |width|, |height| of the partition.
// The current pixel position can be the same as the start pixel position
// if the 4x4 block is the top-left block in the partition. Otherwise, they
// are different.
// Within the same partition, all 4x4 blocks have the same |row_start|,
// |column_start|, |width| and |height|.
// For example, if the frame is partitioned to a 32x32 block,
// starting at (0, 0). Then, there're 64 4x4 blocks within this partition.
// They all have the same |row_start|, |column_start|, |width|, |height|,
// which can be used to figure out the start of the current partition and
// the start of the next partition block.
// Horizontal next: |column_start| + |width|,
// Vertical next: |row_start| + |height|.
std::vector<PartitionInfo> partition_info;
// A vector of the motion vector information of the frame.
// The number of elements is |num_rows_4x4| * |num_cols_4x4|.
// The frame is divided 4x4 blocks of |num_rows_4x4| rows and
// |num_cols_4x4| columns.
// Each 4x4 block contains 0 motion vector if this is an intra predicted
// frame (for example, the key frame). If the frame is inter predicted,
// each 4x4 block contains either 1 or 2 motion vectors.
// Similar to partition info, all 4x4 blocks inside the same partition block
// share the same motion vector information.
std::vector<MotionVectorInfo> motion_vector_info;
ImageBuffer coded_frame;
};
struct GroupOfPicture {
// This list will be updated internally in StartEncode() and
// EncodeFrame()/EncodeFrameWithQuantizeIndex().
// In EncodeFrame()/EncodeFrameWithQuantizeIndex(), the update will only be
// triggered when the coded frame is the last one in the previous group of
// pictures.
std::vector<EncodeFrameInfo> encode_frame_list;
// Indicates the index of the next coding frame in encode_frame_list.
// In other words, EncodeFrameInfo of the next coding frame can be
// obtained with encode_frame_list[next_encode_frame_index].
// Internally, next_encode_frame_index will be set to zero after the last
// frame of the group of pictures is coded. Otherwise, next_encode_frame_index
// will be increased after each EncodeFrame()/EncodeFrameWithQuantizeIndex()
// call.
int next_encode_frame_index;
// Number of show frames in this group of pictures.
int show_frame_count;
// The show index/timestamp of the earliest show frame in the group of
// pictures.
int start_show_index;
// The coding index of the first coding frame in the group of pictures.
int start_coding_index;
// Indicates whether this group of pictures starts with a key frame.
int first_is_key_frame;
// Indicates whether this group of pictures uses an alt ref.
int use_alt_ref;
// Indicates whether previous group of pictures used an alt ref.
int last_gop_use_alt_ref;
};
class SimpleEncode {
public:
// When outfile_path is set, the encoder will output the bitstream in ivf
// format.
SimpleEncode(int frame_width, int frame_height, int frame_rate_num,
int frame_rate_den, int target_bitrate, int num_frames,
const char *infile_path, const char *outfile_path = nullptr);
~SimpleEncode();
SimpleEncode(SimpleEncode &) = delete;
SimpleEncode &operator=(const SimpleEncode &) = delete;
// Makes encoder compute the first pass stats and store it at
// impl_ptr_->first_pass_stats. key_frame_map_ is also computed based on the
// first pass stats.
void ComputeFirstPassStats();
// Outputs the first pass stats represented by a 2-D vector.
// One can use the frame index at first dimension to retrieve the stats for
// each video frame. The stats of each video frame is a vector of 25 double
// values. For details, please check FIRSTPASS_STATS in vp9_firstpass.h
std::vector<std::vector<double>> ObserveFirstPassStats();
// Ouputs a copy of key_frame_map_, a binary vector with size equal to the
// number of show frames in the video. For each entry in the vector, 1
// indicates the position is a key frame and 0 indicates it's not a key frame.
// This function should be called after ComputeFirstPassStats()
std::vector<int> ObserveKeyFrameMap() const;
// Sets group of pictures map for coding the entire video.
// Each entry in the gop_map corresponds to a show frame in the video.
// Therefore, the size of gop_map should equal to the number of show frames in
// the entire video.
// If a given entry's kGopMapFlagStart is set, it means this is the start of a
// gop. Once kGopMapFlagStart is set, one can set kGopMapFlagUseAltRef to
// indicate whether this gop use altref.
// If a given entry is zero, it means it's in the middle of a gop.
// This function should be called only once after ComputeFirstPassStats(),
// before StartEncode().
// This API will check and modify the gop_map to satisfy the following
// constraints.
// 1) Each key frame position should be at the start of a gop.
// 2) The last gop should not use an alt ref.
void SetExternalGroupOfPicturesMap(std::vector<int> gop_map);
// Observe the group of pictures map set through
// SetExternalGroupOfPicturesMap(). This function should be called after
// SetExternalGroupOfPicturesMap().
std::vector<int> ObserveExternalGroupOfPicturesMap();
// Initializes the encoder for actual encoding.
// This function should be called after ComputeFirstPassStats().
void StartEncode();
// Frees the encoder.
// This function should be called after StartEncode() or EncodeFrame().
void EndEncode();
// The key frame group size includes one key frame plus the number of
// following inter frames. Note that the key frame group size only counts the
// show frames. The number of no show frames like alternate refereces are not
// counted.
int GetKeyFrameGroupSize() const;
// Provides the group of pictures that the next coding frame is in.
// Only call this function between StartEncode() and EndEncode()
GroupOfPicture ObserveGroupOfPicture() const;
// Gets encode_frame_info for the next coding frame.
// Only call this function between StartEncode() and EndEncode()
EncodeFrameInfo GetNextEncodeFrameInfo() const;
// Encodes a frame
// This function should be called after StartEncode() and before EndEncode().
void EncodeFrame(EncodeFrameResult *encode_frame_result);
// Encodes a frame with a specific quantize index.
// This function should be called after StartEncode() and before EndEncode().
void EncodeFrameWithQuantizeIndex(EncodeFrameResult *encode_frame_result,
int quantize_index);
// Gets the number of coding frames for the video. The coding frames include
// show frame and no show frame.
// This function should be called after ComputeFirstPassStats().
int GetCodingFrameNum() const;
// Gets the total number of pixels of YUV planes per frame.
uint64_t GetFramePixelCount() const;
private:
// Compute the key frame locations of the video based on first pass stats.
// The results are returned as a binary vector with 1s indicating keyframes
// and 0s indicating non keyframes.
// It has to be called after impl_ptr_->first_pass_stats is computed.
std::vector<int> ComputeKeyFrameMap() const;
// Updates key_frame_group_size_, reset key_frame_group_index_ and init
// ref_frame_info_.
void UpdateKeyFrameGroup(int key_frame_show_index);
// Update key_frame_group_index_.
void PostUpdateKeyFrameGroupIndex(FrameType frame_type);
void PostUpdateState(const EncodeFrameResult &encode_frame_result);
class EncodeImpl;
int frame_width_; // frame width in pixels.
int frame_height_; // frame height in pixels.
int frame_rate_num_;
int frame_rate_den_;
int target_bitrate_;
int num_frames_;
std::FILE *in_file_;
std::FILE *out_file_;
std::unique_ptr<EncodeImpl> impl_ptr_;
std::vector<int> key_frame_map_;
std::vector<int> gop_map_;
GroupOfPicture group_of_picture_;
// The key frame group size includes one key frame plus the number of
// following inter frames. Note that the key frame group size only counts the
// show frames. The number of no show frames like alternate references are not
// counted.
int key_frame_group_size_;
// The index for the to-be-coded show frame in the key frame group.
int key_frame_group_index_;
// Each show or no show frame is assigned with a coding index based on its
// coding order (starting from zero) in the coding process of the entire
// video. The coding index of the to-be-coded frame.
int frame_coding_index_;
// Number of show frames we have coded so far.
int show_frame_count_;
// TODO(angiebird): Do we need to reset ref_frames_info_ when the next key
// frame appears?
// Reference frames info of the to-be-coded frame.
RefFrameInfo ref_frame_info_;
};
} // namespace vp9
#endif // VPX_VP9_SIMPLE_ENCODE_H_