FFmpeg 4.2.2
tx.h
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1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVUTIL_TX_H
20#define AVUTIL_TX_H
21
22#include <stdint.h>
23#include <stddef.h>
24
25typedef struct AVTXContext AVTXContext;
26
27typedef struct AVComplexFloat {
28 float re, im;
30
32 /**
33 * Standard complex to complex FFT with sample data type AVComplexFloat.
34 * Scaling currently unsupported
35 */
37 /**
38 * Standard MDCT with sample data type of float and a scale type of
39 * float. Length is the frame size, not the window size (which is 2x frame)
40 */
42};
43
44/**
45 * Function pointer to a function to perform the transform.
46 *
47 * @note Using a different context than the one allocated during av_tx_init()
48 * is not allowed.
49 *
50 * @param s the transform context
51 * @param out the output array
52 * @param in the input array
53 * @param stride the input or output stride (depending on transform direction)
54 * in bytes, currently implemented for all MDCT transforms
55 */
56typedef void (*av_tx_fn)(AVTXContext *s, void *out, void *in, ptrdiff_t stride);
57
58/**
59 * Initialize a transform context with the given configuration
60 * Currently power of two lengths from 4 to 131072 are supported, along with
61 * any length decomposable to a power of two and either 3, 5 or 15.
62 *
63 * @param ctx the context to allocate, will be NULL on error
64 * @param tx pointer to the transform function pointer to set
65 * @param type type the type of transform
66 * @param inv whether to do an inverse or a forward transform
67 * @param len the size of the transform in samples
68 * @param scale pointer to the value to scale the output if supported by type
69 * @param flags currently unused
70 *
71 * @return 0 on success, negative error code on failure
72 */
73int av_tx_init(AVTXContext **ctx, av_tx_fn *tx, enum AVTXType type,
74 int inv, int len, const void *scale, uint64_t flags);
75
76/**
77 * Frees a context and sets ctx to NULL, does nothing when ctx == NULL
78 */
80
81#endif /* AVUTIL_TX_H */
float im
Definition: tx.h:28
float re
Definition: tx.h:28
void av_tx_uninit(AVTXContext **ctx)
Frees a context and sets ctx to NULL, does nothing when ctx == NULL.
AVTXType
Definition: tx.h:31
@ AV_TX_FLOAT_FFT
Standard complex to complex FFT with sample data type AVComplexFloat.
Definition: tx.h:36
@ AV_TX_FLOAT_MDCT
Standard MDCT with sample data type of float and a scale type of float.
Definition: tx.h:41
int av_tx_init(AVTXContext **ctx, av_tx_fn *tx, enum AVTXType type, int inv, int len, const void *scale, uint64_t flags)
Initialize a transform context with the given configuration Currently power of two lengths from 4 to ...
void(* av_tx_fn)(AVTXContext *s, void *out, void *in, ptrdiff_t stride)
Function pointer to a function to perform the transform.
Definition: tx.h:56
struct AVTXContext AVTXContext
Definition: tx.h:25