87 lines
2.5 KiB
C
87 lines
2.5 KiB
C
/*
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* Project 25 IMBE Encoder/Decoder Fixed-Point implementation
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* Developed by Pavel Yazev E-mail: pyazev@gmail.com
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* Version 1.0 (c) Copyright 2009
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*
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* This is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* The software is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this; see the file COPYING. If not, write to the Free
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* Software Foundation, Inc., 51 Franklin Street, Boston, MA
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* 02110-1301, USA.
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*/
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#ifndef _QNT_SUB
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#define _QNT_SUB
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#define CNST_0_5_Q0_16 0x8000
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//-----------------------------------------------------------------------------
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// PURPOSE:
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// Dequantize by quantizer step size
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//
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//
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// INPUT:
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// qval - quantized value
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// step_size - step size used to quantize in unsigned Q0.16 format
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// bit_num - the number of bits
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//
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// OUTPUT:
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// None
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//
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// RETURN:
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// Quantized Value in signed (bit_num).16 format
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//
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//-----------------------------------------------------------------------------
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Word32 deqnt_by_step(Word16 qval, UWord16 step_size, Word16 bit_num);
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//-----------------------------------------------------------------------------
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// PURPOSE:
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// Quantize by quantizer step size
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//
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//
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// INPUT:
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// val - value to be quantized
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// step_size - step size used to quantize in unsigned Q0.16 format
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// bit_num - the number of bits
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//
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// OUTPUT:
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// None
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//
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// RETURN:
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// Quantized Value in integer
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//
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//-----------------------------------------------------------------------------
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Word16 qnt_by_step(Word16 val, UWord16 step_size, Word16 bit_num);
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//-----------------------------------------------------------------------------
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// PURPOSE:
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// Quantize by table
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//
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//
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// INPUT:
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// val - value to be quantized
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// q_tbl - pointer to table
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// q_tbl_size - size of table
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//
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// OUTPUT:
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// None
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//
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// RETURN:
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// Quantized Value in integer
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//
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//-----------------------------------------------------------------------------
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Word16 tbl_quant(Word16 val, Word16 *q_tbl, Word16 q_tbl_size);
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#endif
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