51 lines
1.7 KiB
C
51 lines
1.7 KiB
C
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/*
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* jdsample.h
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*
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* This file was part of the Independent JPEG Group's software:
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* Copyright (C) 1991-1996, Thomas G. Lane.
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* For conditions of distribution and use, see the accompanying README.ijg
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* file.
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*/
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#define JPEG_INTERNALS
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#include "jpeglib.h"
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/* Pointer to routine to upsample a single component */
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typedef void (*upsample1_ptr) (j_decompress_ptr cinfo,
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jpeg_component_info *compptr,
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JSAMPARRAY input_data,
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JSAMPARRAY *output_data_ptr);
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/* Private subobject */
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typedef struct {
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struct jpeg_upsampler pub; /* public fields */
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/* Color conversion buffer. When using separate upsampling and color
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* conversion steps, this buffer holds one upsampled row group until it
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* has been color converted and output.
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* Note: we do not allocate any storage for component(s) which are full-size,
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* ie do not need rescaling. The corresponding entry of color_buf[] is
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* simply set to point to the input data array, thereby avoiding copying.
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*/
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JSAMPARRAY color_buf[MAX_COMPONENTS];
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/* Per-component upsampling method pointers */
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upsample1_ptr methods[MAX_COMPONENTS];
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int next_row_out; /* counts rows emitted from color_buf */
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JDIMENSION rows_to_go; /* counts rows remaining in image */
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/* Height of an input row group for each component. */
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int rowgroup_height[MAX_COMPONENTS];
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/* These arrays save pixel expansion factors so that int_expand need not
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* recompute them each time. They are unused for other upsampling methods.
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*/
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UINT8 h_expand[MAX_COMPONENTS];
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UINT8 v_expand[MAX_COMPONENTS];
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} my_upsampler;
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typedef my_upsampler *my_upsample_ptr;
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