41 строка
1.6 KiB
C
41 строка
1.6 KiB
C
/*
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* Copyright (c) 2016 The WebM project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef VPX_DSP_BLEND_H_
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#define VPX_DSP_BLEND_H_
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#include "vpx_ports/mem.h"
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// Various blending functions and macros.
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// See also the vpx_blend_* functions in vpx_dsp_rtcd.h
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// Alpha blending with alpha values from the range [0, 64], where 64
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// means use the first input and 0 means use the second input.
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#define VPX_BLEND_A64_ROUND_BITS 6
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#define VPX_BLEND_A64_MAX_ALPHA (1 << VPX_BLEND_A64_ROUND_BITS) // 64
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#define VPX_BLEND_A64(a, v0, v1) \
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ROUND_POWER_OF_TWO((a) * (v0) + (VPX_BLEND_A64_MAX_ALPHA - (a)) * (v1), \
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VPX_BLEND_A64_ROUND_BITS)
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// Alpha blending with alpha values from the range [0, 256], where 256
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// means use the first input and 0 means use the second input.
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#define VPX_BLEND_A256_ROUND_BITS 8
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#define VPX_BLEND_A256_MAX_ALPHA (1 << VPX_BLEND_A256_ROUND_BITS) // 256
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#define VPX_BLEND_A256(a, v0, v1) \
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ROUND_POWER_OF_TWO((a) * (v0) + (VPX_BLEND_A256_MAX_ALPHA - (a)) * (v1), \
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VPX_BLEND_A256_ROUND_BITS)
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// Blending by averaging.
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#define VPX_BLEND_AVG(v0, v1) ROUND_POWER_OF_TWO((v0) + (v1), 1)
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#endif // VPX_DSP_BLEND_H_
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