1// Copyright 2012 Google Inc. All Rights Reserved.
2//
3// Use of this source code is governed by a BSD-style license
4// that can be found in the COPYING file in the root of the source
5// tree. An additional intellectual property rights grant can be found
6// in the file PATENTS. All contributing project authors may
7// be found in the AUTHORS file in the root of the source tree.
8// -----------------------------------------------------------------------------
9//
10// Lossless encoder: internal header.
11//
12// Author: Vikas Arora (vikaas.arora@gmail.com)
13
14#ifndef WEBP_ENC_VP8LI_ENC_H_
15#define WEBP_ENC_VP8LI_ENC_H_
16
17#ifdef HAVE_CONFIG_H
18#include "src/webp/config.h"
19#endif
20// Either WEBP_NEAR_LOSSLESS is defined as 0 in config.h when compiling to
21// disable near-lossless, or it is enabled by default.
22#ifndef WEBP_NEAR_LOSSLESS
23#define WEBP_NEAR_LOSSLESS 1
24#endif
25
26#include "src/enc/backward_references_enc.h"
27#include "src/enc/histogram_enc.h"
28#include "src/utils/bit_writer_utils.h"
29#include "src/webp/encode.h"
30#include "src/webp/format_constants.h"
31
32#ifdef __cplusplus
33extern "C" {
34#endif
35
36// maximum value of transform_bits_ in VP8LEncoder.
37#define MAX_TRANSFORM_BITS 6
38
39typedef enum {
40 kEncoderNone = 0,
41 kEncoderARGB,
42 kEncoderNearLossless,
43 kEncoderPalette
44} VP8LEncoderARGBContent;
45
46typedef struct {
47 const WebPConfig* config_; // user configuration and parameters
48 const WebPPicture* pic_; // input picture.
49
50 uint32_t* argb_; // Transformed argb image data.
51 VP8LEncoderARGBContent argb_content_; // Content type of the argb buffer.
52 uint32_t* argb_scratch_; // Scratch memory for argb rows
53 // (used for prediction).
54 uint32_t* transform_data_; // Scratch memory for transform data.
55 uint32_t* transform_mem_; // Currently allocated memory.
56 size_t transform_mem_size_; // Currently allocated memory size.
57
58 int current_width_; // Corresponds to packed image width.
59
60 // Encoding parameters derived from quality parameter.
61 int histo_bits_;
62 int transform_bits_; // <= MAX_TRANSFORM_BITS.
63 int cache_bits_; // If equal to 0, don't use color cache.
64
65 // Encoding parameters derived from image characteristics.
66 int use_cross_color_;
67 int use_subtract_green_;
68 int use_predict_;
69 int use_palette_;
70 int palette_size_;
71 uint32_t palette_[MAX_PALETTE_SIZE];
72
73 // Some 'scratch' (potentially large) objects.
74 struct VP8LBackwardRefs refs_[3]; // Backward Refs array for temporaries.
75 VP8LHashChain hash_chain_; // HashChain data for constructing
76 // backward references.
77} VP8LEncoder;
78
79//------------------------------------------------------------------------------
80// internal functions. Not public.
81
82// Encodes the picture.
83// Returns 0 if config or picture is NULL or picture doesn't have valid argb
84// input.
85int VP8LEncodeImage(const WebPConfig* const config,
86 const WebPPicture* const picture);
87
88// Encodes the main image stream using the supplied bit writer.
89// If 'use_cache' is false, disables the use of color cache.
90WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
91 const WebPPicture* const picture,
92 VP8LBitWriter* const bw, int use_cache);
93
94#if (WEBP_NEAR_LOSSLESS == 1)
95// in near_lossless.c
96// Near lossless preprocessing in RGB color-space.
97int VP8ApplyNearLossless(const WebPPicture* const picture, int quality,
98 uint32_t* const argb_dst);
99#endif
100
101//------------------------------------------------------------------------------
102// Image transforms in predictor.c.
103
104void VP8LResidualImage(int width, int height, int bits, int low_effort,
105 uint32_t* const argb, uint32_t* const argb_scratch,
106 uint32_t* const image, int near_lossless, int exact,
107 int used_subtract_green);
108
109void VP8LColorSpaceTransform(int width, int height, int bits, int quality,
110 uint32_t* const argb, uint32_t* image);
111
112//------------------------------------------------------------------------------
113
114#ifdef __cplusplus
115} // extern "C"
116#endif
117
118#endif // WEBP_ENC_VP8LI_ENC_H_
119