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_H_
15 #define WEBP_ENC_VP8LI_H_
16 
17 #include "./backward_references.h"
18 #include "./histogram.h"
19 #include "../utils/bit_writer.h"
20 #include "webp/encode.h"
21 #include "webp/format_constants.h"
22 
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26 
27 typedef struct {
28   const WebPConfig* config_;    // user configuration and parameters
29   const WebPPicture* pic_;      // input picture.
30 
31   uint32_t* argb_;              // Transformed argb image data.
32   uint32_t* argb_scratch_;      // Scratch memory for argb rows
33                                 // (used for prediction).
34   uint32_t* transform_data_;    // Scratch memory for transform data.
35   int       current_width_;     // Corresponds to packed image width.
36 
37   // Encoding parameters derived from quality parameter.
38   int histo_bits_;
39   int transform_bits_;
40   int cache_bits_;        // If equal to 0, don't use color cache.
41 
42   // Encoding parameters derived from image characteristics.
43   int use_cross_color_;
44   int use_subtract_green_;
45   int use_predict_;
46   int use_palette_;
47   int palette_size_;
48   uint32_t palette_[MAX_PALETTE_SIZE];
49 
50   // Some 'scratch' (potentially large) objects.
51   struct VP8LBackwardRefs refs_[2];  // Backward Refs array corresponding to
52                                      // LZ77 & RLE coding.
53   VP8LHashChain hash_chain_;         // HashChain data for constructing
54                                      // backward references.
55 } VP8LEncoder;
56 
57 //------------------------------------------------------------------------------
58 // internal functions. Not public.
59 
60 // Encodes the picture.
61 // Returns 0 if config or picture is NULL or picture doesn't have valid argb
62 // input.
63 int VP8LEncodeImage(const WebPConfig* const config,
64                     const WebPPicture* const picture);
65 
66 // Encodes the main image stream using the supplied bit writer.
67 WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
68                                    const WebPPicture* const picture,
69                                    VP8LBitWriter* const bw);
70 
71 //------------------------------------------------------------------------------
72 
73 #ifdef __cplusplus
74 }    // extern "C"
75 #endif
76 
77 #endif  /* WEBP_ENC_VP8LI_H_ */
78