xref: /third_party/ffmpeg/libavutil/lls.h (revision cabdff1a)
1/*
2 * linear least squares model
3 *
4 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#ifndef AVUTIL_LLS_H
24#define AVUTIL_LLS_H
25
26#include "macros.h"
27#include "mem_internal.h"
28
29#define MAX_VARS 32
30#define MAX_VARS_ALIGN FFALIGN(MAX_VARS+1,4)
31
32//FIXME avoid direct access to LLSModel from outside
33
34/**
35 * Linear least squares model.
36 */
37typedef struct LLSModel {
38    DECLARE_ALIGNED(32, double, covariance[MAX_VARS_ALIGN][MAX_VARS_ALIGN]);
39    DECLARE_ALIGNED(32, double, coeff[MAX_VARS][MAX_VARS]);
40    double variance[MAX_VARS];
41    int indep_count;
42    /**
43     * Take the outer-product of var[] with itself, and add to the covariance matrix.
44     * @param m this context
45     * @param var training samples, starting with the value to be predicted
46     *            32-byte aligned, and any padding elements must be initialized
47     *            (i.e not denormal/nan).
48     */
49    void (*update_lls)(struct LLSModel *m, const double *var);
50    /**
51     * Inner product of var[] and the LPC coefs.
52     * @param m this context
53     * @param var training samples, excluding the value to be predicted. unaligned.
54     * @param order lpc order
55     */
56    double (*evaluate_lls)(struct LLSModel *m, const double *var, int order);
57} LLSModel;
58
59void avpriv_init_lls(LLSModel *m, int indep_count);
60void ff_init_lls_x86(LLSModel *m);
61void avpriv_solve_lls(LLSModel *m, double threshold, unsigned short min_order);
62
63#endif /* AVUTIL_LLS_H */
64