opus/celt/laplace.h

/* Copyright (c) 2007-2012 IETF Trust, CSIRO, Xiph.Org Foundation. All rights reserved.
   Written by Jean-Marc Valin */
/*

   This file is extracted from RFC6716. Please see that RFC for additional
   information.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   - Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   - Neither the name of Internet Society, IETF or IETF Trust, nor the
   names of specific contributors, may be used to endorse or promote
   products derived from this software without specific prior written
   permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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*/

#include "entenc.h"
#include "entdec.h"

/** Encode a value that is assumed to be the realisation of a
    Laplace-distributed random process
 @param enc Entropy encoder state
 @param value Value to encode
 @param fs Probability of 0, multiplied by 32768
 @param decay Probability of the value +/- 1, multiplied by 16384
*/
void ec_laplace_encode(ec_enc *enc, int *value, unsigned fs, int decay);

/** Decode a value that is assumed to be the realisation of a
    Laplace-distributed random process
 @param dec Entropy decoder state
 @param fs Probability of 0, multiplied by 32768
 @param decay Probability of the value +/- 1, multiplied by 16384
 @return Value decoded
 */
int ec_laplace_decode(ec_dec *dec, unsigned fs, int decay);