45 lines
993 B
C
45 lines
993 B
C
/*
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* Copyright (c) 2010 The VP8 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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#include <stdlib.h>
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#include "blockd.h"
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void vp8_predict_dc(short *lastdc, short *thisdc, short quant, short *cons)
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{
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int diff;
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int sign;
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int last_dc = *lastdc;
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int this_dc = *thisdc;
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if (*cons > DCPREDCNTTHRESH)
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{
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this_dc += last_dc;
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}
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diff = abs(last_dc - this_dc);
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sign = (last_dc >> 31) ^(this_dc >> 31);
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sign |= (!last_dc | !this_dc);
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if (sign)
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{
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*cons = 0;
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}
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else
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{
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if (diff <= DCPREDSIMTHRESH * quant)
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(*cons)++ ;
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}
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*thisdc = this_dc;
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*lastdc = this_dc;
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}
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