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Diffstat (limited to 'drivers/webp/enc/vp8enci.h')
| -rw-r--r-- | drivers/webp/enc/vp8enci.h | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/drivers/webp/enc/vp8enci.h b/drivers/webp/enc/vp8enci.h new file mode 100644 index 0000000000..71adf6c38a --- /dev/null +++ b/drivers/webp/enc/vp8enci.h @@ -0,0 +1,570 @@ +// Copyright 2011 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. +// ----------------------------------------------------------------------------- +// +// 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 "../dsp/dsp.h" +#include "../utils/bit_writer.h" +#include "../utils/thread.h" + +#ifdef __cplusplus +extern "C" { +#endif + +//------------------------------------------------------------------------------ +// Various defines and enums + +// version numbers +#define ENC_MAJ_VERSION 0 +#define ENC_MIN_VERSION 4 +#define ENC_REV_VERSION 0 + +// 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, + NUM_PRED_MODES = 4 + }; + +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 + MAX_LEVEL = 2047 // max level (note: max codable is 2047 + 67) + }; + +typedef enum { // Rate-distortion optimization levels + RD_OPT_NONE = 0, // no rd-opt + RD_OPT_BASIC = 1, // basic scoring (no trellis) + RD_OPT_TRELLIS = 2, // perform trellis-quant on the final decision only + RD_OPT_TRELLIS_ALL = 3 // trellis-quant for every scoring (much slower) +} VP8RDLevel; + +// 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 ('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 WEBP_INLINE int QUANTDIV(int n, int iQ, int B) { + return (n * iQ + B) >> QFIX; +} + +// size of histogram used by CollectHistogram. +#define MAX_COEFF_THRESH 31 +typedef struct VP8Histogram VP8Histogram; +struct VP8Histogram { + // TODO(skal): we only need to store the max_value and last_non_zero actually. + int distribution[MAX_COEFF_THRESH + 1]; +}; + +// Uncomment the following to remove token-buffer code: +// #define DISABLE_TOKEN_BUFFER + +//------------------------------------------------------------------------------ +// Headers + +typedef uint32_t proba_t; // 16b + 16b +typedef uint8_t ProbaArray[NUM_CTX][NUM_PROBAS]; +typedef proba_t StatsArray[NUM_CTX][NUM_PROBAS]; +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]; // 4224 bytes + CostArray level_cost_[NUM_TYPES][NUM_BANDS]; // 11.4k + int dirty_; // if true, need to call VP8CalculateLevelCosts() + 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 VP8Matrix { + 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 + int max_edge_; // max edge delta (for filtering strength) + int min_disto_; // minimum distortion required to trigger filtering record + // 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 transient struct to accumulate score and info during RD-optimization +// and mode evaluation. +typedef struct { + score_t D, SD; // Distortion, spectral distortion + score_t H, R, score; // header bits, 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 + uint8_t 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_stride_, uv_stride_; // respective strides + uint8_t* yuv_in_; // input samples + uint8_t* yuv_out_; // output samples + uint8_t* yuv_out2_; // secondary buffer swapped with yuv_out_. + uint8_t* yuv_p_; // scratch buffer for prediction + 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 count_down_; // number of mb still to be processed + int count_down0_; // starting counter value (for progress) + int percent0_; // saved initial progress percent + + uint8_t* y_left_; // left luma samples (addressable from index -1 to 15). + uint8_t* u_left_; // left u samples (addressable from index -1 to 7) + uint8_t* v_left_; // left v samples (addressable from index -1 to 7) + + uint8_t* y_top_; // top luma samples at position 'x_' + uint8_t* uv_top_; // top u/v samples at position 'x_', packed as 16 bytes + + // memory for storing y/u/v_left_ and yuv_in_/out_* + uint8_t yuv_left_mem_[17 + 16 + 16 + 8 + ALIGN_CST]; // memory for *_left_ + uint8_t yuv_mem_[3 * YUV_SIZE + PRED_SIZE + ALIGN_CST]; // memory for yuv_* +} VP8EncIterator; + + // in iterator.c +// must be called first +void VP8IteratorInit(VP8Encoder* const enc, VP8EncIterator* const it); +// restart a scan +void VP8IteratorReset(VP8EncIterator* const it); +// reset iterator position to row 'y' +void VP8IteratorSetRow(VP8EncIterator* const it, int y); +// set count down (=number of iterations to go) +void VP8IteratorSetCountDown(VP8EncIterator* const it, int count_down); +// return true if iteration is finished +int VP8IteratorIsDone(const VP8EncIterator* const it); +// Import uncompressed samples from source. +// If tmp_32 is not NULL, import boundary samples too. +// tmp_32 is a 32-bytes scratch buffer that must be aligned in memory. +void VP8IteratorImport(VP8EncIterator* const it, uint8_t* tmp_32); +// export decimated samples +void VP8IteratorExport(const VP8EncIterator* const it); +// go to next macroblock. Returns false if not finished. +int VP8IteratorNext(VP8EncIterator* const it); +// save the yuv_out_ boundary values to top_/left_ arrays for next iterations. +void VP8IteratorSaveBoundary(VP8EncIterator* const it); +// Report progression based on macroblock rows. Return 0 for user-abort request. +int VP8IteratorProgress(const VP8EncIterator* const it, + int final_delta_percent); +// 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, const uint8_t* modes); +void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode); +void VP8SetSkip(const VP8EncIterator* const it, int skip); +void VP8SetSegment(const VP8EncIterator* const it, int segment); + +//------------------------------------------------------------------------------ +// Paginated token buffer + +typedef struct VP8Tokens VP8Tokens; // struct details in token.c + +typedef struct { +#if !defined(DISABLE_TOKEN_BUFFER) + VP8Tokens* pages_; // first page + VP8Tokens** last_page_; // last page + uint16_t* tokens_; // set to (*last_page_)->tokens_ + int left_; // how many free tokens left before the page is full. +#endif + int error_; // true in case of malloc error +} VP8TBuffer; + +void VP8TBufferInit(VP8TBuffer* const b); // initialize an empty buffer +void VP8TBufferClear(VP8TBuffer* const b); // de-allocate pages memory + +#if !defined(DISABLE_TOKEN_BUFFER) + +// Finalizes bitstream when probabilities are known. +// Deletes the allocated token memory if final_pass is true. +int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw, + const uint8_t* const probas, int final_pass); + +// record the coding of coefficients without knowing the probabilities yet +int VP8RecordCoeffTokens(int ctx, int coeff_type, int first, int last, + const int16_t* const coeffs, + VP8TBuffer* const tokens); + +// Estimate the final coded size given a set of 'probas'. +size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas); + +// unused for now +void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats); + +#endif // !DISABLE_TOKEN_BUFFER + +//------------------------------------------------------------------------------ +// 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 + VP8TBuffer tokens_; // token buffer + + int percent_; // for progress + + // transparency blob + int has_alpha_; + uint8_t* alpha_data_; // non-NULL if transparency is present + uint32_t alpha_data_size_; + WebPWorker alpha_worker_; + + // 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 alpha_; // global susceptibility (<=> complexity) + 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_[4]; // sum of Y/U/V/A 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. + VP8RDLevel rd_opt_level_; // Deduced from method_. + int max_i4_header_bits_; // partition #0 safeness factor + int thread_level_; // derived from config->thread_level + int do_search_; // derived from config->target_XXX + int use_tokens_; // if true, use token buffer + + // 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 *y_top_; // top luma samples. + uint8_t *uv_top_; // top u/v samples. + // U and V are packed into 16 bytes (8 U + 8 V) + 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); +// Release memory allocated for bit-writing in VP8EncLoop & seq. +void VP8EncFreeBitWriters(VP8Encoder* const enc); + + // in frame.c +extern const uint8_t VP8EncBands[16 + 1]; +extern const uint8_t VP8Cat3[]; +extern const uint8_t VP8Cat4[]; +extern const uint8_t VP8Cat5[]; +extern const uint8_t VP8Cat6[]; + +// 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 coding calls +int VP8EncLoop(VP8Encoder* const enc); +int VP8EncTokenLoop(VP8Encoder* const enc); + + // in webpenc.c +// Assign an error code to a picture. Return false for convenience. +int WebPEncodingSetError(const WebPPicture* const pic, WebPEncodingError error); +int WebPReportProgress(const WebPPicture* const pic, + int percent, int* const percent_store); + + // in analysis.c +// 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, + VP8RDLevel rd_opt); + + // in alpha.c +void VP8EncInitAlpha(VP8Encoder* const enc); // initialize alpha compression +int VP8EncStartAlpha(VP8Encoder* const enc); // start alpha coding process +int VP8EncFinishAlpha(VP8Encoder* const enc); // finalize compressed data +int VP8EncDeleteAlpha(VP8Encoder* const 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 filter.c + +// SSIM utils +typedef struct { + double w, xm, ym, xxm, xym, yym; +} DistoStats; +void VP8SSIMAddStats(const DistoStats* const src, DistoStats* const dst); +void VP8SSIMAccumulatePlane(const uint8_t* src1, int stride1, + const uint8_t* src2, int stride2, + int W, int H, DistoStats* const stats); +double VP8SSIMGet(const DistoStats* const stats); +double VP8SSIMGetSquaredError(const DistoStats* const stats); + +// autofilter +void VP8InitFilter(VP8EncIterator* const it); +void VP8StoreFilterStats(VP8EncIterator* const it); +void VP8AdjustFilterStrength(VP8EncIterator* const it); + +// returns the approximate filtering strength needed to smooth a edge +// step of 'delta', given a sharpness parameter 'sharpness'. +int VP8FilterStrengthFromDelta(int sharpness, int delta); + +//------------------------------------------------------------------------------ + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif /* WEBP_ENC_VP8ENCI_H_ */ |