// Copyright 2011 Google Inc. // // This code is licensed under the same terms as WebM: // Software License Agreement: http://www.webmproject.org/license/software/ // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ // ----------------------------------------------------------------------------- // // WebP encoder: internal header. // // Author: Skal (pascal.massimino@gmail.com) #ifndef WEBP_ENC_VP8ENCI_H_ #define WEBP_ENC_VP8ENCI_H_ #include "string.h" // for memcpy() #include "../webp/encode.h" #include "bit_writer.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif //------------------------------------------------------------------------------ // Various defines and enums // version numbers #define ENC_MAJ_VERSION 0 #define ENC_MIN_VERSION 1 #define ENC_REV_VERSION 3 // size of histogram used by CollectHistogram. #define MAX_COEFF_THRESH 64 // intra prediction modes enum { B_DC_PRED = 0, // 4x4 modes B_TM_PRED = 1, B_VE_PRED = 2, B_HE_PRED = 3, B_RD_PRED = 4, B_VR_PRED = 5, B_LD_PRED = 6, B_VL_PRED = 7, B_HD_PRED = 8, B_HU_PRED = 9, 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 }; enum { NUM_MB_SEGMENTS = 4, MAX_NUM_PARTITIONS = 8, NUM_TYPES = 4, // 0: i16-AC, 1: i16-DC, 2:chroma-AC, 3:i4-AC NUM_BANDS = 8, NUM_CTX = 3, NUM_PROBAS = 11, MAX_LF_LEVELS = 64, // Maximum loop filter level MAX_VARIABLE_LEVEL = 67 // last (inclusive) level with variable cost }; // YUV-cache parameters. Cache is 16-pixels wide. // The original or reconstructed samples can be accessed using VP8Scan[] // The predicted blocks can be accessed using offsets to yuv_p_ and // the arrays VP8*ModeOffsets[]; // +----+ YUV Samples area. See VP8Scan[] for accessing the blocks. // Y_OFF |YYYY| <- original samples (enc->yuv_in_) // |YYYY| // |YYYY| // |YYYY| // U_OFF |UUVV| V_OFF (=U_OFF + 8) // |UUVV| // +----+ // Y_OFF |YYYY| <- compressed/decoded samples ('yuv_out_') // |YYYY| There are two buffers like this ('yuv_out_'/'yuv_out2_') // |YYYY| // |YYYY| // U_OFF |UUVV| V_OFF // |UUVV| // x2 (for yuv_out2_) // +----+ Prediction area ('yuv_p_', size = PRED_SIZE) // I16DC16 |YYYY| Intra16 predictions (16x16 block each) // |YYYY| // |YYYY| // |YYYY| // I16TM16 |YYYY| // |YYYY| // |YYYY| // |YYYY| // I16VE16 |YYYY| // |YYYY| // |YYYY| // |YYYY| // I16HE16 |YYYY| // |YYYY| // |YYYY| // |YYYY| // +----+ Chroma U/V predictions (16x8 block each) // C8DC8 |UUVV| // |UUVV| // C8TM8 |UUVV| // |UUVV| // C8VE8 |UUVV| // |UUVV| // C8HE8 |UUVV| // |UUVV| // +----+ Intra 4x4 predictions (4x4 block each) // |YYYY| I4DC4 I4TM4 I4VE4 I4HE4 // |YYYY| I4RD4 I4VR4 I4LD4 I4VL4 // |YY..| I4HD4 I4HU4 I4TMP // +----+ #define BPS 16 // this is the common stride #define Y_SIZE (BPS * 16) #define UV_SIZE (BPS * 8) #define YUV_SIZE (Y_SIZE + UV_SIZE) #define PRED_SIZE (6 * 16 * BPS + 12 * BPS) #define Y_OFF (0) #define U_OFF (Y_SIZE) #define V_OFF (U_OFF + 8) #define ALIGN_CST 15 #define DO_ALIGN(PTR) ((uintptr_t)((PTR) + ALIGN_CST) & ~ALIGN_CST) extern const int VP8Scan[16 + 4 + 4]; // in quant.c extern const int VP8UVModeOffsets[4]; // in analyze.c extern const int VP8I16ModeOffsets[4]; extern const int VP8I4ModeOffsets[NUM_BMODES]; // Layout of prediction blocks // intra 16x16 #define I16DC16 (0 * 16 * BPS) #define I16TM16 (1 * 16 * BPS) #define I16VE16 (2 * 16 * BPS) #define I16HE16 (3 * 16 * BPS) // chroma 8x8, two U/V blocks side by side (hence: 16x8 each) #define C8DC8 (4 * 16 * BPS) #define C8TM8 (4 * 16 * BPS + 8 * BPS) #define C8VE8 (5 * 16 * BPS) #define C8HE8 (5 * 16 * BPS + 8 * BPS) // intra 4x4 #define I4DC4 (6 * 16 * BPS + 0) #define I4TM4 (6 * 16 * BPS + 4) #define I4VE4 (6 * 16 * BPS + 8) #define I4HE4 (6 * 16 * BPS + 12) #define I4RD4 (6 * 16 * BPS + 4 * BPS + 0) #define I4VR4 (6 * 16 * BPS + 4 * BPS + 4) #define I4LD4 (6 * 16 * BPS + 4 * BPS + 8) #define I4VL4 (6 * 16 * BPS + 4 * BPS + 12) #define I4HD4 (6 * 16 * BPS + 8 * BPS + 0) #define I4HU4 (6 * 16 * BPS + 8 * BPS + 4) #define I4TMP (6 * 16 * BPS + 8 * BPS + 8) typedef int64_t score_t; // type used for scores, rate, distortion #define MAX_COST ((score_t)0x7fffffffffffffLL) #define QFIX 17 #define BIAS(b) ((b) << (QFIX - 8)) // Fun fact: this is the _only_ line where we're actually being lossy and // discarding bits. static inline int QUANTDIV(int n, int iQ, int B) { return (n * iQ + B) >> QFIX; } extern const uint8_t VP8Zigzag[16]; //------------------------------------------------------------------------------ // Headers typedef uint8_t ProbaArray[NUM_CTX][NUM_PROBAS]; typedef uint64_t StatsArray[NUM_CTX][NUM_PROBAS][2]; typedef uint16_t CostArray[NUM_CTX][MAX_VARIABLE_LEVEL + 1]; typedef double LFStats[NUM_MB_SEGMENTS][MAX_LF_LEVELS]; // filter stats typedef struct VP8Encoder VP8Encoder; // segment features typedef struct { int num_segments_; // Actual number of segments. 1 segment only = unused. int update_map_; // whether to update the segment map or not. // must be 0 if there's only 1 segment. int size_; // bit-cost for transmitting the segment map } VP8SegmentHeader; // Struct collecting all frame-persistent probabilities. typedef struct { uint8_t segments_[3]; // probabilities for segment tree uint8_t skip_proba_; // final probability of being skipped. ProbaArray coeffs_[NUM_TYPES][NUM_BANDS]; // 924 bytes StatsArray stats_[NUM_TYPES][NUM_BANDS]; // 7.4k CostArray level_cost_[NUM_TYPES][NUM_BANDS]; // 11.4k int use_skip_proba_; // Note: we always use skip_proba for now. int nb_skip_; // number of skipped blocks } VP8Proba; // Filter parameters. Not actually used in the code (we don't perform // the in-loop filtering), but filled from user's config typedef struct { int simple_; // filtering type: 0=complex, 1=simple int level_; // base filter level [0..63] int sharpness_; // [0..7] int i4x4_lf_delta_; // delta filter level for i4x4 relative to i16x16 } VP8FilterHeader; //------------------------------------------------------------------------------ // Informations about the macroblocks. typedef struct { // block type unsigned int type_:2; // 0=i4x4, 1=i16x16 unsigned int uv_mode_:2; unsigned int skip_:1; unsigned int segment_:2; uint8_t alpha_; // quantization-susceptibility } VP8MBInfo; typedef struct { uint16_t q_[16]; // quantizer steps uint16_t iq_[16]; // reciprocals, fixed point. uint16_t bias_[16]; // rounding bias uint16_t zthresh_[16]; // value under which a coefficient is zeroed uint16_t sharpen_[16]; // frequency boosters for slight sharpening } VP8Matrix; typedef struct { VP8Matrix y1_, y2_, uv_; // quantization matrices int alpha_; // quant-susceptibility, range [-127,127]. Zero is neutral. // Lower values indicate a lower risk of blurriness. int beta_; // filter-susceptibility, range [0,255]. int quant_; // final segment quantizer. int fstrength_; // final in-loop filtering strength // reactivities int lambda_i16_, lambda_i4_, lambda_uv_; int lambda_mode_, lambda_trellis_, tlambda_; int lambda_trellis_i16_, lambda_trellis_i4_, lambda_trellis_uv_; } VP8SegmentInfo; // Handy transcient struct to accumulate score and info during RD-optimization // and mode evaluation. typedef struct { score_t D, SD, R, score; // Distortion, spectral distortion, rate, score. int16_t y_dc_levels[16]; // Quantized levels for luma-DC, luma-AC, chroma. int16_t y_ac_levels[16][16]; int16_t uv_levels[4 + 4][16]; int mode_i16; // mode number for intra16 prediction int modes_i4[16]; // mode numbers for intra4 predictions int mode_uv; // mode number of chroma prediction uint32_t nz; // non-zero blocks } VP8ModeScore; // Iterator structure to iterate through macroblocks, pointing to the // right neighbouring data (samples, predictions, contexts, ...) typedef struct { int x_, y_; // current macroblock int y_offset_, uv_offset_; // offset to the luma / chroma planes int y_stride_, uv_stride_; // respective strides uint8_t* yuv_in_; // borrowed from enc_ (for now) uint8_t* yuv_out_; // '' uint8_t* yuv_out2_; // '' uint8_t* yuv_p_; // '' VP8Encoder* enc_; // back-pointer VP8MBInfo* mb_; // current macroblock VP8BitWriter* bw_; // current bit-writer uint8_t* preds_; // intra mode predictors (4x4 blocks) uint32_t* nz_; // non-zero pattern uint8_t i4_boundary_[37]; // 32+5 boundary samples needed by intra4x4 uint8_t* i4_top_; // pointer to the current top boundary sample int i4_; // current intra4x4 mode being tested int top_nz_[9]; // top-non-zero context. int left_nz_[9]; // left-non-zero. left_nz[8] is independent. uint64_t bit_count_[4][3]; // bit counters for coded levels. uint64_t luma_bits_; // macroblock bit-cost for luma uint64_t uv_bits_; // macroblock bit-cost for chroma LFStats* lf_stats_; // filter stats (borrowed from enc_) int do_trellis_; // if true, perform extra level optimisation int done_; // true when scan is finished } VP8EncIterator; // in iterator.c // must be called first. void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it); // restart a scan. void VP8IteratorReset(VP8EncIterator* const it); // import samples from source void VP8IteratorImport(const VP8EncIterator* const it); // export decimated samples void VP8IteratorExport(const VP8EncIterator* const it); // go to next macroblock. Returns !done_. If *block_to_save is non-null, will // save the boundary values to top_/left_ arrays. block_to_save can be // it->yuv_out_ or it->yuv_in_. int VP8IteratorNext(VP8EncIterator* const it, const uint8_t* const block_to_save); // Intra4x4 iterations void VP8IteratorStartI4(VP8EncIterator* const it); // returns true if not done. int VP8IteratorRotateI4(VP8EncIterator* const it, const uint8_t* const yuv_out); // Non-zero context setup/teardown void VP8IteratorNzToBytes(VP8EncIterator* const it); void VP8IteratorBytesToNz(VP8EncIterator* const it); // Helper functions to set mode properties void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode); void VP8SetIntra4Mode(const VP8EncIterator* const it, int modes[16]); void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode); void VP8SetSkip(const VP8EncIterator* const it, int skip); void VP8SetSegment(const VP8EncIterator* const it, int segment); void VP8IteratorResetCosts(VP8EncIterator* const it); //------------------------------------------------------------------------------ // VP8Encoder struct VP8Encoder { const WebPConfig* config_; // user configuration and parameters WebPPicture* pic_; // input / output picture // headers VP8FilterHeader filter_hdr_; // filtering information VP8SegmentHeader segment_hdr_; // segment information int profile_; // VP8's profile, deduced from Config. // dimension, in macroblock units. int mb_w_, mb_h_; int preds_w_; // stride of the *preds_ prediction plane (=4*mb_w + 1) // number of partitions (1, 2, 4 or 8 = MAX_NUM_PARTITIONS) int num_parts_; // per-partition boolean decoders. VP8BitWriter bw_; // part0 VP8BitWriter parts_[MAX_NUM_PARTITIONS]; // token partitions // transparency blob int has_alpha_; uint8_t* alpha_data_; // non-NULL if transparency is present size_t alpha_data_size_; // enhancement layer int use_layer_; VP8BitWriter layer_bw_; uint8_t* layer_data_; size_t layer_data_size_; // quantization info (one set of DC/AC dequant factor per segment) VP8SegmentInfo dqm_[NUM_MB_SEGMENTS]; int base_quant_; // nominal quantizer value. Only used // for relative coding of segments' quant. int uv_alpha_; // U/V quantization susceptibility // global offset of quantizers, shared by all segments int dq_y1_dc_; int dq_y2_dc_, dq_y2_ac_; int dq_uv_dc_, dq_uv_ac_; // probabilities and statistics VP8Proba proba_; uint64_t sse_[3]; // sum of Y/U/V squared errors for all macroblocks uint64_t sse_count_; // pixel count for the sse_[] stats int coded_size_; int residual_bytes_[3][4]; int block_count_[3]; // quality/speed settings int method_; // 0=fastest, 6=best/slowest. int rd_opt_level_; // Deduced from method_. int max_i4_header_bits_; // partition #0 safeness factor // Memory VP8MBInfo* mb_info_; // contextual macroblock infos (mb_w_ + 1) uint8_t* preds_; // predictions modes: (4*mb_w+1) * (4*mb_h+1) uint32_t* nz_; // non-zero bit context: mb_w+1 uint8_t* yuv_in_; // input samples uint8_t* yuv_out_; // output samples uint8_t* yuv_out2_; // secondary scratch out-buffer. swapped with yuv_out_. uint8_t* yuv_p_; // scratch buffer for prediction uint8_t *y_top_; // top luma samples. uint8_t *uv_top_; // top u/v samples. // U and V are packed into 16 pixels (8 U + 8 V) uint8_t *y_left_; // left luma samples (adressable from index -1 to 15). uint8_t *u_left_; // left u samples (adressable from index -1 to 7) uint8_t *v_left_; // left v samples (adressable from index -1 to 7) LFStats *lf_stats_; // autofilter stats (if NULL, autofilter is off) }; //------------------------------------------------------------------------------ // internal functions. Not public. // in tree.c extern const uint8_t VP8CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS]; extern const uint8_t VP8CoeffsUpdateProba[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS]; // Reset the token probabilities to their initial (default) values void VP8DefaultProbas(VP8Encoder* const enc); // Write the token probabilities void VP8WriteProbas(VP8BitWriter* const bw, const VP8Proba* const probas); // Writes the partition #0 modes (that is: all intra modes) void VP8CodeIntraModes(VP8Encoder* const enc); // in syntax.c // Generates the final bitstream by coding the partition0 and headers, // and appending an assembly of all the pre-coded token partitions. // Return true if everything is ok. int VP8EncWrite(VP8Encoder* const enc); // in frame.c extern const uint8_t VP8EncBands[16 + 1]; // Form all the four Intra16x16 predictions in the yuv_p_ cache void VP8MakeLuma16Preds(const VP8EncIterator* const it); // Form all the four Chroma8x8 predictions in the yuv_p_ cache void VP8MakeChroma8Preds(const VP8EncIterator* const it); // Form all the ten Intra4x4 predictions in the yuv_p_ cache // for the 4x4 block it->i4_ void VP8MakeIntra4Preds(const VP8EncIterator* const it); // Rate calculation int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd); int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]); int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd); // Main stat / coding passes int VP8EncLoop(VP8Encoder* const enc); int VP8StatLoop(VP8Encoder* const enc); // in webpenc.c // Assign an error code to a picture. Return false for convenience. int WebPEncodingSetError(WebPPicture* const pic, WebPEncodingError error); // in analysis.c // Compute susceptibility based on DCT-coeff histograms: // the higher, the "easier" the macroblock is to compress. typedef int (*VP8CHisto)(const uint8_t* ref, const uint8_t* pred, int start_block, int end_block); extern VP8CHisto VP8CollectHistogram; // Main analysis loop. Decides the segmentations and complexity. // Assigns a first guess for Intra16 and uvmode_ prediction modes. int VP8EncAnalyze(VP8Encoder* const enc); // in quant.c // Sets up segment's quantization values, base_quant_ and filter strengths. void VP8SetSegmentParams(VP8Encoder* const enc, float quality); // Pick best modes and fills the levels. Returns true if skipped. int VP8Decimate(VP8EncIterator* const it, VP8ModeScore* const rd, int rd_opt); // in alpha.c void VP8EncInitAlpha(VP8Encoder* enc); // initialize alpha compression void VP8EncCodeAlphaBlock(VP8EncIterator* it); // analyze or code a macroblock int VP8EncFinishAlpha(VP8Encoder* enc); // finalize compressed data void VP8EncDeleteAlpha(VP8Encoder* enc); // delete compressed data // in layer.c void VP8EncInitLayer(VP8Encoder* const enc); // init everything void VP8EncCodeLayerBlock(VP8EncIterator* it); // code one more macroblock int VP8EncFinishLayer(VP8Encoder* const enc); // finalize coding void VP8EncDeleteLayer(VP8Encoder* enc); // reclaim memory // in dsp.c int VP8GetAlpha(const int histo[MAX_COEFF_THRESH + 1]); // Transforms // VP8Idct: Does one of two inverse transforms. If do_two is set, the transforms // will be done for (ref, in, dst) and (ref + 4, in + 16, dst + 4). typedef void (*VP8Idct)(const uint8_t* ref, const int16_t* in, uint8_t* dst, int do_two); typedef void (*VP8Fdct)(const uint8_t* src, const uint8_t* ref, int16_t* out); typedef void (*VP8WHT)(const int16_t* in, int16_t* out); extern VP8Idct VP8ITransform; extern VP8Fdct VP8FTransform; extern VP8WHT VP8ITransformWHT; extern VP8WHT VP8FTransformWHT; // Predictions // *dst is the destination block. *top, *top_right and *left can be NULL. typedef void (*VP8IntraPreds)(uint8_t *dst, const uint8_t* left, const uint8_t* top); typedef void (*VP8Intra4Preds)(uint8_t *dst, const uint8_t* top); extern VP8Intra4Preds VP8EncPredLuma4; extern VP8IntraPreds VP8EncPredLuma16; extern VP8IntraPreds VP8EncPredChroma8; typedef int (*VP8Metric)(const uint8_t* pix, const uint8_t* ref); extern VP8Metric VP8SSE16x16, VP8SSE16x8, VP8SSE8x8, VP8SSE4x4; typedef int (*VP8WMetric)(const uint8_t* pix, const uint8_t* ref, const uint16_t* const weights); extern VP8WMetric VP8TDisto4x4, VP8TDisto16x16; typedef void (*VP8BlockCopy)(const uint8_t* src, uint8_t* dst); extern VP8BlockCopy VP8Copy4x4; extern VP8BlockCopy VP8Copy8x8; extern VP8BlockCopy VP8Copy16x16; // Quantization typedef int (*VP8QuantizeBlock)(int16_t in[16], int16_t out[16], int n, const VP8Matrix* const mtx); extern VP8QuantizeBlock VP8EncQuantizeBlock; typedef enum { kSSE2, kSSE3 } CPUFeature; // returns true if the CPU supports the feature. typedef int (*VP8CPUInfo)(CPUFeature feature); extern VP8CPUInfo VP8EncGetCPUInfo; void VP8EncDspInit(void); // must be called before using any of the above // in filter.c extern void VP8InitFilter(VP8EncIterator* const it); extern void VP8StoreFilterStats(VP8EncIterator* const it); extern void VP8AdjustFilterStrength(VP8EncIterator* const it); //------------------------------------------------------------------------------ #if defined(__cplusplus) || defined(c_plusplus) } // extern "C" #endif #endif // WEBP_ENC_VP8ENCI_H_