1 // Copyright 2013 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 // Alpha decoder: internal header.
11 //
12 // Author: Urvang (urvang@google.com)
13 
14 #ifndef WEBP_DEC_ALPHAI_DEC_H_
15 #define WEBP_DEC_ALPHAI_DEC_H_
16 
17 #include "src/dec/webpi_dec.h"
18 #include "src/utils/filters_utils.h"
19 
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23 
24 struct VP8LDecoder;  // Defined in dec/vp8li.h.
25 
26 typedef struct ALPHDecoder ALPHDecoder;
27 struct ALPHDecoder {
28   int width_;
29   int height_;
30   int method_;
31   WEBP_FILTER_TYPE filter_;
32   int pre_processing_;
33   struct VP8LDecoder* vp8l_dec_;
34   VP8Io io_;
35   int use_8b_decode_;  // Although alpha channel requires only 1 byte per
36                        // pixel, sometimes VP8LDecoder may need to allocate
37                        // 4 bytes per pixel internally during decode.
38   uint8_t* output_;
39   const uint8_t* prev_line_;   // last output row (or NULL)
40 };
41 
42 //------------------------------------------------------------------------------
43 // internal functions. Not public.
44 
45 // Deallocate memory associated to dec->alpha_plane_ decoding
46 void WebPDeallocateAlphaMemory(VP8Decoder* const dec);
47 
48 //------------------------------------------------------------------------------
49 
50 #ifdef __cplusplus
51 }    // extern "C"
52 #endif
53 
54 #endif  /* WEBP_DEC_ALPHAI_DEC_H_ */
55