github.com/cellofellow/gopkg@v0.0.0-20140722061823-eec0544a62ad/image/webp/libwebp/src/dec/alphai.h (about)

     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_H_
    15  #define WEBP_DEC_ALPHAI_H_
    16  
    17  #include "./webpi.h"
    18  #include "../utils/filters.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  };
    39  
    40  //------------------------------------------------------------------------------
    41  // internal functions. Not public.
    42  
    43  // Allocates a new alpha decoder instance.
    44  ALPHDecoder* ALPHNew(void);
    45  
    46  // Clears and deallocates an alpha decoder instance.
    47  void ALPHDelete(ALPHDecoder* const dec);
    48  
    49  //------------------------------------------------------------------------------
    50  
    51  #ifdef __cplusplus
    52  }    // extern "C"
    53  #endif
    54  
    55  #endif  /* WEBP_DEC_ALPHAI_H_ */