libwebp-0.6.0-rc1

third_party/libwebp/enc/vp8enci.h

-// 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 "../dec/common.h"
-#include "../dsp/dsp.h"
-#include "../utils/bit_writer.h"
-#include "../utils/thread.h"
-#include "../utils/utils.h"
-#include "../webp/encode.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-//------------------------------------------------------------------------------
-// Various defines and enums
-
-// version numbers
-#define ENC_MAJ_VERSION 0
-#define ENC_MIN_VERSION 5
-#define ENC_REV_VERSION 2
-
-enum { 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 32-bytes wide (= one cacheline).
-// 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 (yuv_in_/yuv_out_/yuv_out2_)
-//   (see VP8Scan[] for accessing the blocks, along with
-//   Y_OFF_ENC/U_OFF_ENC/V_OFF_ENC):
-//             +----+----+
-//  Y_OFF_ENC  |YYYY|UUVV|
-//  U_OFF_ENC  |YYYY|UUVV|
-//  V_OFF_ENC  |YYYY|....| <- 25% wasted U/V area
-//             |YYYY|....|
-//             +----+----+
-// * Prediction area ('yuv_p_', size = PRED_SIZE_ENC)
-//   Intra16 predictions (16x16 block each, two per row):
-//         |I16DC16|I16TM16|
-//         |I16VE16|I16HE16|
-//   Chroma U/V predictions (16x8 block each, two per row):
-//         |C8DC8|C8TM8|
-//         |C8VE8|C8HE8|
-//   Intra 4x4 predictions (4x4 block each)
-//         |I4DC4 I4TM4 I4VE4 I4HE4|I4RD4 I4VR4 I4LD4 I4VL4|
-//         |I4HD4 I4HU4 I4TMP .....|.......................| <- ~31% wasted
-#define YUV_SIZE_ENC (BPS * 16)
-#define PRED_SIZE_ENC (32 * BPS + 16 * BPS + 8 * BPS)   // I16+Chroma+I4 preds
-#define Y_OFF_ENC    (0)
-#define U_OFF_ENC    (16)
-#define V_OFF_ENC    (16 + 8)
-
-extern const int VP8Scan[16];           // 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 (I16DC16 + 16)
-#define I16VE16 (1 * 16 * BPS)
-#define I16HE16 (I16VE16 + 16)
-// chroma 8x8, two U/V blocks side by side (hence: 16x8 each)
-#define C8DC8 (2 * 16 * BPS)
-#define C8TM8 (C8DC8 + 1 * 16)
-#define C8VE8 (2 * 16 * BPS + 8 * BPS)
-#define C8HE8 (C8VE8 + 1 * 16)
-// intra 4x4
-#define I4DC4 (3 * 16 * BPS +  0)
-#define I4TM4 (I4DC4 +  4)
-#define I4VE4 (I4DC4 +  8)
-#define I4HE4 (I4DC4 + 12)
-#define I4RD4 (I4DC4 + 16)
-#define I4VR4 (I4DC4 + 20)
-#define I4LD4 (I4DC4 + 24)
-#define I4VL4 (I4DC4 + 28)
-#define I4HD4 (3 * 16 * BPS + 4 * BPS)
-#define I4HU4 (I4HD4 + 4)
-#define I4TMP (I4HD4 + 8)
-
-typedef int64_t score_t;     // type used for scores, rate, distortion
-// Note that MAX_COST is not the maximum allowed by sizeof(score_t),
-// in order to allow overflowing computations.
-#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(uint32_t n, uint32_t iQ, uint32_t B) {
-  return (int)((n * iQ + B) >> QFIX);
-}
-
-// 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 const uint16_t* (*CostArrayPtr)[NUM_CTX];   // for easy casting
-typedef const uint16_t* CostArrayMap[16][NUM_CTX];
-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
-} VP8EncSegmentHeader;
-
-// 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];      // 1056 bytes
-  StatsArray stats_[NUM_TYPES][NUM_BANDS];       // 4224 bytes
-  CostArray level_cost_[NUM_TYPES][NUM_BANDS];   // 13056 bytes
-  CostArrayMap remapped_costs_[NUM_TYPES];       // 1536 bytes
-  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
-} VP8EncProba;
-
-// 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
-} VP8EncFilterHeader;
-
-//------------------------------------------------------------------------------
-// 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.
-  uint32_t bias_[16];     // rounding bias
-  uint32_t zthresh_[16];  // value below 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_;
-
-  // lambda values for distortion-based evaluation
-  score_t i4_penalty_;   // penalty for using Intra4
-} 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_
-  uint8_t yuv_left_mem_[17 + 16 + 16 + 8 + WEBP_ALIGN_CST];
-  // memory for yuv_*
-  uint8_t yuv_mem_[3 * YUV_SIZE_ENC + PRED_SIZE_ENC + WEBP_ALIGN_CST];
-} 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
-  int page_size_;           // number of tokens per page
-#endif
-  int error_;         // true in case of malloc error
-} VP8TBuffer;
-
-// initialize an empty buffer
-void VP8TBufferInit(VP8TBuffer* const b, int page_size);
-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, const struct VP8Residual* const res,
-                         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
-  VP8EncFilterHeader   filter_hdr_;     // filtering information
-  VP8EncSegmentHeader  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_;
-
-  // 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
-  VP8EncProba 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 mb_header_limit_;      // rough limit for header bits per MB
-  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 VP8EncProba* 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 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 filter.c
-void VP8SSIMAddStats(const VP8DistoStats* const src, VP8DistoStats* const dst);
-void VP8SSIMAccumulatePlane(const uint8_t* src1, int stride1,
-                            const uint8_t* src2, int stride2,
-                            int W, int H, VP8DistoStats* const stats);
-double VP8SSIMGet(const VP8DistoStats* const stats);
-double VP8SSIMGetSquaredError(const VP8DistoStats* 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);
-
-  // misc utils for picture_*.c:
-
-// Remove reference to the ARGB/YUVA buffer (doesn't free anything).
-void WebPPictureResetBuffers(WebPPicture* const picture);
-
-// Allocates ARGB buffer of given dimension (previous one is always free'd).
-// Preserves the YUV(A) buffer. Returns false in case of error (invalid param,
-// out-of-memory).
-int WebPPictureAllocARGB(WebPPicture* const picture, int width, int height);
-
-// Allocates YUVA buffer of given dimension (previous one is always free'd).
-// Uses picture->csp to determine whether an alpha buffer is needed.
-// Preserves the ARGB buffer.
-// Returns false in case of error (invalid param, out-of-memory).
-int WebPPictureAllocYUVA(WebPPicture* const picture, int width, int height);
-
-// Clean-up the RGB samples under fully transparent area, to help lossless
-// compressibility (no guarantee, though). Assumes that pic->use_argb is true.
-void WebPCleanupTransparentAreaLossless(WebPPicture* const pic);
-
-  // in near_lossless.c
-// Near lossless preprocessing in RGB color-space.
-int VP8ApplyNearLossless(int xsize, int ysize, uint32_t* argb, int quality);
-// Near lossless adjustment for predictors.
-void VP8ApplyNearLosslessPredict(int xsize, int ysize, int pred_bits,
-                                 const uint32_t* argb_orig,
-                                 uint32_t* argb, uint32_t* argb_scratch,
-                                 const uint32_t* const transform_data,
-                                 int quality, int subtract_green);
-//------------------------------------------------------------------------------
-
-#ifdef __cplusplus
-}    // extern "C"
-#endif
-
-#endif  /* WEBP_ENC_VP8ENCI_H_ */