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 // Sorted version of palette_ for cache purposes.
73 uint32_t palette_sorted_[MAX_PALETTE_SIZE];
74
75 // Some 'scratch' (potentially large) objects.
76 struct VP8LBackwardRefs refs_[4]; // Backward Refs array for temporaries.
77 VP8LHashChain hash_chain_; // HashChain data for constructing
78 // backward references.
79} VP8LEncoder;
80
81//------------------------------------------------------------------------------
82// internal functions. Not public.
83
84// Encodes the picture.
85// Returns 0 if config or picture is NULL or picture doesn't have valid argb
86// input.
87int VP8LEncodeImage(const WebPConfig* const config,
88 const WebPPicture* const picture);
89
90// Encodes the main image stream using the supplied bit writer.
91// If 'use_cache' is false, disables the use of color cache.
92// Returns false in case of error (stored in picture->error_code).
93int VP8LEncodeStream(const WebPConfig* const config,
94 const WebPPicture* const picture, VP8LBitWriter* const bw,
95 int use_cache);
96
97#if (WEBP_NEAR_LOSSLESS == 1)
98// in near_lossless.c
99// Near lossless preprocessing in RGB color-space.
100int VP8ApplyNearLossless(const WebPPicture* const picture, int quality,
101 uint32_t* const argb_dst);
102#endif
103
104//------------------------------------------------------------------------------
105// Image transforms in predictor.c.
106
107// pic and percent are for progress.
108// Returns false in case of error (stored in pic->error_code).
109int VP8LResidualImage(int width, int height, int bits, int low_effort,
110 uint32_t* const argb, uint32_t* const argb_scratch,
111 uint32_t* const image, int near_lossless, int exact,
112 int used_subtract_green, const WebPPicture* const pic,
113 int percent_range, int* const percent);
114
115int VP8LColorSpaceTransform(int width, int height, int bits, int quality,
116 uint32_t* const argb, uint32_t* image,
117 const WebPPicture* const pic, int percent_range,
118 int* const percent);
119
120//------------------------------------------------------------------------------
121
122#ifdef __cplusplus
123} // extern "C"
124#endif
125
126#endif // WEBP_ENC_VP8LI_ENC_H_
127