Add WebP library to Chromium...

third_party/libwebp/vp8i.h

+// Copyright 2010 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/
+// -----------------------------------------------------------------------------
+//
+// VP8 decoder: internal header.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifndef WEBP_DECODE_VP8I_H_
+#define WEBP_DECODE_VP8I_H_
+
+#include <string.h>     // for memcpy()
+#include "bits.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+//-----------------------------------------------------------------------------
+// Various defines and enums
+
+#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_LD_PRED,
+       B_RD_PRED,
+       B_VR_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 };
+
+#ifndef ONLY_KEYFRAME_CODE
+// inter prediction modes
+enum {
+  LEFT4 = 0, ABOVE4 = 1, ZERO4 = 2, NEW4 = 3,
+  NEARESTMV, NEARMV, ZEROMV, NEWMV, SPLITMV };
+#endif
+
+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 {
+  // block type
+  uint8_t skip_:1;
+  // filter specs
+  uint8_t f_level_:6;      // filter strength: 0..63
+  uint8_t f_ilevel_:6;     // inner limit: 1..63
+  uint8_t f_inner_:1;      // do inner filtering?
+  // cbp
+  uint8_t nz_;        // non-zero AC/DC coeffs
+  uint8_t dc_nz_;     // non-zero DC coeffs
+} VP8MB;
+
+// Dequantization matrices
+typedef struct {
+  uint16_t y1_mat_[2], y2_mat_[2], uv_mat_[2];    // [DC / AC]
+} VP8QuantMatrix;
+
+//-----------------------------------------------------------------------------
+// VP8Decoder: the main opaque structure handed over to user
+
+struct VP8Decoder {
+  int status_;    // 0 = OK
+  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_;
+
+  // dimension, in macroblock units.
+  int mb_w_, mb_h_;
+
+  // 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_, proba_saved_;
+  int update_proba_;
+  int use_skip_proba_;
+  uint8_t skip_p_, intra_p_, last_p_, golden_p_;
+
+  // 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 infos (mb_w_ + 1)
+  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_;
+  int 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
+  uint8_t filter_levels_[NUM_MB_SEGMENTS];  // precalculated per-segment
+};
+
+//-----------------------------------------------------------------------------
+// internal functions. Not public.
+
+// in vp8.c
+int VP8SetError(VP8Decoder* const dec, int error, const char *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);
+// Filtering
+void VP8StoreBlock(VP8Decoder* const dec);
+void VP8FilterRow(VP8Decoder* const dec, VP8Io* io);
+
+// in dsp.c
+typedef void (*VP8Idct)(const int16_t* coeffs, uint8_t* dst);
+extern VP8Idct VP8Transform;
+extern VP8Idct VP8TransformUV;
+extern VP8Idct VP8TransformDC;
+extern VP8Idct VP8TransformDCUV;
+extern void (*VP8TransformWHT)(const int16_t* in, int16_t* out);
+
+// *dst is the destination block, with stride BPS. Boundary samples are
+// assumed accessible when needed.
+typedef void (*VP8PredFunc)(uint8_t *dst);
+extern VP8PredFunc VP8PredLuma16[7];
+extern VP8PredFunc VP8PredChroma8[7];
+extern VP8PredFunc VP8PredLuma4[11];
+
+void VP8DspInit();        // must be called before anything using the above
+void VP8DspInitTables();  // needs to be called no matter what.
+
+// simple filter (only for luma)
+typedef void (*VP8SimpleFilterFunc)(uint8_t* p, int stride, int thresh);
+extern VP8SimpleFilterFunc VP8SimpleVFilter16;
+extern VP8SimpleFilterFunc VP8SimpleHFilter16;
+extern VP8SimpleFilterFunc VP8SimpleVFilter16i;  // filter 3 inner edges
+extern VP8SimpleFilterFunc VP8SimpleHFilter16i;
+
+// regular filter (on both macroblock edges and inner edges)
+typedef void (*VP8LumaFilterFunc)(uint8_t* luma, int stride,
+                                  int thresh, int ithresh, int hev_t);
+typedef void (*VP8ChromaFilterFunc)(uint8_t* u, uint8_t* v, int stride,
+                                    int thresh, int ithresh, int hev_t);
+// on outter edge
+extern VP8LumaFilterFunc VP8VFilter16;
+extern VP8LumaFilterFunc VP8HFilter16;
+extern VP8ChromaFilterFunc VP8VFilter8;
+extern VP8ChromaFilterFunc VP8HFilter8;
+
+// on inner edge
+extern VP8LumaFilterFunc VP8VFilter16i;   // filtering 3 inner edges altogether
+extern VP8LumaFilterFunc VP8HFilter16i;
+extern VP8ChromaFilterFunc VP8VFilter8i;  // filtering u and v altogether
+extern VP8ChromaFilterFunc VP8HFilter8i;
+
+//-----------------------------------------------------------------------------
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}    // extern "C"
+#endif
+
+#endif  // WEBP_DECODE_VP8I_H_