// Copyright 2010 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING 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.
// -----------------------------------------------------------------------------
//
// VP8 decoder: internal header.
//
// Author: Skal (pascal.massimino@gmail.com)
#ifndef WEBP_DEC_VP8I_H_
#define WEBP_DEC_VP8I_H_
#include <string.h> // for memcpy()
#include "./vp8li.h"
#include "../utils/bit_reader.h"
#include "../utils/thread.h"
#include "../dsp/dsp.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//------------------------------------------------------------------------------
// Various defines and enums
// version numbers
#define DEC_MAJ_VERSION 0
#define DEC_MIN_VERSION 3
#define DEC_REV_VERSION 1
#define ONLY_KEYFRAME_CODE // to remove any code related to P-Frames
// intra prediction modes
enum { B_DC_PRED = 0, // 4x4 modes
B_TM_PRED,
B_VE_PRED,
B_HE_PRED,
B_RD_PRED,
B_VR_PRED,
B_LD_PRED,
B_VL_PRED,
B_HD_PRED,
B_HU_PRED,
NUM_BMODES = B_HU_PRED + 1 - B_DC_PRED, // = 10
// Luma16 or UV modes
DC_PRED = B_DC_PRED, V_PRED = B_VE_PRED,
H_PRED = B_HE_PRED, TM_PRED = B_TM_PRED,
B_PRED = NUM_BMODES, // refined I4x4 mode
// special modes
B_DC_PRED_NOTOP = 4,
B_DC_PRED_NOLEFT = 5,
B_DC_PRED_NOTOPLEFT = 6,
NUM_B_DC_MODES = 7 };
enum { MB_FEATURE_TREE_PROBS = 3,
NUM_MB_SEGMENTS = 4,
NUM_REF_LF_DELTAS = 4,
NUM_MODE_LF_DELTAS = 4, // I4x4, ZERO, *, SPLIT
MAX_NUM_PARTITIONS = 8,
// Probabilities
NUM_TYPES = 4,
NUM_BANDS = 8,
NUM_CTX = 3,
NUM_PROBAS = 11,
NUM_MV_PROBAS = 19 };
// YUV-cache parameters.
// Constraints are: We need to store one 16x16 block of luma samples (y),
// and two 8x8 chroma blocks (u/v). These are better be 16-bytes aligned,
// in order to be SIMD-friendly. We also need to store the top, left and
// top-left samples (from previously decoded blocks), along with four
// extra top-right samples for luma (intra4x4 prediction only).
// One possible layout is, using 32 * (17 + 9) bytes:
//
// .+------ <- only 1 pixel high
// .|yyyyt.
// .|yyyyt.
// .|yyyyt.
// .|yyyy..
// .+--.+-- <- only 1 pixel high
// .|uu.|vv
// .|uu.|vv
//
// Every character is a 4x4 block, with legend:
// '.' = unused
// 'y' = y-samples 'u' = u-samples 'v' = u-samples
// '|' = left sample, '-' = top sample, '+' = top-left sample
// 't' = extra top-right sample for 4x4 modes
// With this layout, BPS (=Bytes Per Scan-line) is one cacheline size.
#define BPS 32 // this is the common stride used by yuv[]
#define YUV_SIZE (BPS * 17 + BPS * 9)
#define Y_SIZE (BPS * 17)
#define Y_OFF (BPS * 1 + 8)
#define U_OFF (Y_OFF + BPS * 16 + BPS)
#define V_OFF (U_OFF + 16)
//------------------------------------------------------------------------------
// Headers
typedef struct {
uint8_t key_frame_;
uint8_t profile_;
uint8_t show_;
uint32_t partition_length_;
} VP8FrameHeader;
typedef struct {
uint16_t width_;
uint16_t height_;
uint8_t xscale_;
uint8_t yscale_;
uint8_t colorspace_; // 0 = YCbCr
uint8_t clamp_type_;
} VP8PictureHeader;
// segment features
typedef struct {
int use_segment_;
int update_map_; // whether to update the segment map or not
int absolute_delta_; // absolute or delta values for quantizer and filter
int8_t quantizer_[NUM_MB_SEGMENTS]; // quantization changes
int8_t filter_strength_[NUM_MB_SEGMENTS]; // filter strength for segments
} VP8SegmentHeader;
// Struct collecting all frame-persistent probabilities.
typedef struct {
uint8_t segments_[MB_FEATURE_TREE_PROBS];
// Type: 0:Intra16-AC 1:Intra16-DC 2:Chroma 3:Intra4
uint8_t coeffs_[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS];
#ifndef ONLY_KEYFRAME_CODE
uint8_t ymode_[4], uvmode_[3];
uint8_t mv_[2][NUM_MV_PROBAS];
#endif
} VP8Proba;
// Filter parameters
typedef struct {
int simple_; // 0=complex, 1=simple
int level_; // [0..63]
int sharpness_; // [0..7]
int use_lf_delta_;
int ref_lf_delta_[NUM_REF_LF_DELTAS];
int mode_lf_delta_[NUM_MODE_LF_DELTAS];
} VP8FilterHeader;
//------------------------------------------------------------------------------
// Informations about the macroblocks.
typedef struct { // filter specs
unsigned int f_level_:6; // filter strength: 0..63
unsigned int f_ilevel_:6; // inner limit: 1..63
unsigned int f_inner_:1; // do inner filtering?
} VP8FInfo;
typedef struct { // used for syntax-parsing
unsigned int nz_:24; // non-zero AC/DC coeffs (24bit)
unsigned int dc_nz_:1; // non-zero DC coeffs
unsigned int skip_:1; // block type
} VP8MB;
// Dequantization matrices
typedef int quant_t[2]; // [DC / AC]. Can be 'uint16_t[2]' too (~slower).
typedef struct {
quant_t y1_mat_, y2_mat_, uv_mat_;
} VP8QuantMatrix;
// Persistent information needed by the parallel processing
typedef struct {
int id_; // cache row to process (in [0..2])
int mb_y_; // macroblock position of the row
int filter_row_; // true if row-filtering is needed
VP8FInfo* f_info_; // filter strengths
VP8Io io_; // copy of the VP8Io to pass to put()
} VP8ThreadContext;
//------------------------------------------------------------------------------
// VP8Decoder: the main opaque structure handed over to user
struct VP8Decoder {
VP8StatusCode status_;
int ready_; // true if ready to decode a picture with VP8Decode()
const char* error_msg_; // set when status_ is not OK.
// Main data source
VP8BitReader br_;
// headers
VP8FrameHeader frm_hdr_;
VP8PictureHeader pic_hdr_;
VP8FilterHeader filter_hdr_;
VP8SegmentHeader segment_hdr_;
// Worker
WebPWorker worker_;
int use_threads_; // use multi-thread
int cache_id_; // current cache row
int num_caches_; // number of cached rows of 16 pixels (1, 2 or 3)
VP8ThreadContext thread_ctx_; // Thread context
// dimension, in macroblock units.
int mb_w_, mb_h_;
// Macroblock to process/filter, depending on cropping and filter_type.
int tl_mb_x_, tl_mb_y_; // top-left MB that must be in-loop filtered
int br_mb_x_, br_mb_y_; // last bottom-right MB that must be decoded
// number of partitions.
int num_parts_;
// per-partition boolean decoders.
VP8BitReader parts_[MAX_NUM_PARTITIONS];
// buffer refresh flags
// bit 0: refresh Gold, bit 1: refresh Alt
// bit 2-3: copy to Gold, bit 4-5: copy to Alt
// bit 6: Gold sign bias, bit 7: Alt sign bias
// bit 8: refresh last frame
uint32_t buffer_flags_;
// dequantization (one set of DC/AC dequant factor per segment)
VP8QuantMatrix dqm_[NUM_MB_SEGMENTS];
// probabilities
VP8Proba proba_;
int use_skip_proba_;
uint8_t skip_p_;
#ifndef ONLY_KEYFRAME_CODE
uint8_t intra_p_, last_p_, golden_p_;
VP8Proba proba_saved_;
int update_proba_;
#endif
// Boundary data cache and persistent buffers.
uint8_t* intra_t_; // top intra modes values: 4 * mb_w_
uint8_t intra_l_[4]; // left intra modes values
uint8_t* y_t_; // top luma samples: 16 * mb_w_
uint8_t* u_t_, *v_t_; // top u/v samples: 8 * mb_w_ each
VP8MB* mb_info_; // contextual macroblock info (mb_w_ + 1)
VP8FInfo* f_info_; // filter strength info
uint8_t* yuv_b_; // main block for Y/U/V (size = YUV_SIZE)
int16_t* coeffs_; // 384 coeffs = (16+8+8) * 4*4
uint8_t* cache_y_; // macroblock row for storing unfiltered samples
uint8_t* cache_u_;
uint8_t* cache_v_;
int cache_y_stride_;
int cache_uv_stride_;
// main memory chunk for the above data. Persistent.
void* mem_;
size_t mem_size_;
// Per macroblock non-persistent infos.
int mb_x_, mb_y_; // current position, in macroblock units
uint8_t is_i4x4_; // true if intra4x4
uint8_t imodes_[16]; // one 16x16 mode (#0) or sixteen 4x4 modes
uint8_t uvmode_; // chroma prediction mode
uint8_t segment_; // block's segment
// bit-wise info about the content of each sub-4x4 blocks: there are 16 bits
// for luma (bits #0->#15), then 4 bits for chroma-u (#16->#19) and 4 bits for
// chroma-v (#20->#23), each corresponding to one 4x4 block in decoding order.
// If the bit is set, the 4x4 block contains some non-zero coefficients.
uint32_t non_zero_;
uint32_t non_zero_ac_;
// Filtering side-info
int filter_type_; // 0=off, 1=simple, 2=complex
int filter_row_; // per-row flag
VP8FInfo fstrengths_[NUM_MB_SEGMENTS][2]; // precalculated per-segment/type
// extensions
const uint8_t* alpha_data_; // compressed alpha data (if present)
size_t alpha_data_size_;
int is_alpha_decoded_; // true if alpha_data_ is decoded in alpha_plane_
uint8_t* alpha_plane_; // output. Persistent, contains the whole data.
int layer_colorspace_;
const uint8_t* layer_data_; // compressed layer data (if present)
size_t layer_data_size_;
};
//------------------------------------------------------------------------------
// internal functions. Not public.
// in vp8.c
int VP8SetError(VP8Decoder* const dec,
VP8StatusCode error, const char* const msg);
// in tree.c
void VP8ResetProba(VP8Proba* const proba);
void VP8ParseProba(VP8BitReader* const br, VP8Decoder* const dec);
void VP8ParseIntraMode(VP8BitReader* const br, VP8Decoder* const dec);
// in quant.c
void VP8ParseQuant(VP8Decoder* const dec);
// in frame.c
int VP8InitFrame(VP8Decoder* const dec, VP8Io* io);
// Predict a block and add residual
void VP8ReconstructBlock(VP8Decoder* const dec);
// Call io->setup() and finish setting up scan parameters.
// After this call returns, one must always call VP8ExitCritical() with the
// same parameters. Both functions should be used in pair. Returns VP8_STATUS_OK
// if ok, otherwise sets and returns the error status on *dec.
VP8StatusCode VP8EnterCritical(VP8Decoder* const dec, VP8Io* const io);
// Must always be called in pair with VP8EnterCritical().
// Returns false in case of error.
int VP8ExitCritical(VP8Decoder* const dec, VP8Io* const io);
// Process the last decoded row (filtering + output)
int VP8ProcessRow(VP8Decoder* const dec, VP8Io* const io);
// To be called at the start of a new scanline, to initialize predictors.
void VP8InitScanline(VP8Decoder* const dec);
// Decode one macroblock. Returns false if there is not enough data.
int VP8DecodeMB(VP8Decoder* const dec, VP8BitReader* const token_br);
// in alpha.c
const uint8_t* VP8DecompressAlphaRows(VP8Decoder* const dec,
int row, int num_rows);
// in layer.c
int VP8DecodeLayer(VP8Decoder* const dec);
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif
#endif /* WEBP_DEC_VP8I_H_ */