xref: /aosp_15_r20/external/libopus/celt/laplace.h (revision a58d3d2adb790c104798cd88c8a3aff4fa8b82cc)
1 /* Copyright (c) 2007 CSIRO
2    Copyright (c) 2007-2009 Xiph.Org Foundation
3    Written by Jean-Marc Valin */
4 /*
5    Redistribution and use in source and binary forms, with or without
6    modification, are permitted provided that the following conditions
7    are met:
8 
9    - Redistributions of source code must retain the above copyright
10    notice, this list of conditions and the following disclaimer.
11 
12    - Redistributions in binary form must reproduce the above copyright
13    notice, this list of conditions and the following disclaimer in the
14    documentation and/or other materials provided with the distribution.
15 
16    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
20    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
23    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
24    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
25    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
26    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28 
29 #ifndef LAPLACE_H
30 #define LAPLACE_H
31 
32 #include "entenc.h"
33 #include "entdec.h"
34 
35 /** Encode a value that is assumed to be the realisation of a
36     Laplace-distributed random process
37  @param enc Entropy encoder state
38  @param value Value to encode
39  @param fs Probability of 0, multiplied by 32768
40  @param decay Probability of the value +/- 1, multiplied by 16384
41 */
42 void ec_laplace_encode(ec_enc *enc, int *value, unsigned fs, int decay);
43 
44 /** Decode a value that is assumed to be the realisation of a
45     Laplace-distributed random process
46  @param dec Entropy decoder state
47  @param fs Probability of 0, multiplied by 32768
48  @param decay Probability of the value +/- 1, multiplied by 16384
49  @return Value decoded
50  */
51 int ec_laplace_decode(ec_dec *dec, unsigned fs, int decay);
52 
53 
54 int ec_laplace_decode_p0(ec_dec *dec, opus_uint16 p0, opus_uint16 decay);
55 void ec_laplace_encode_p0(ec_enc *enc, int value, opus_uint16 p0, opus_uint16 decay);
56 
57 #endif
58