2 * This file is part of FFmpeg.
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.
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.
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
25 typedef struct AVTXContext AVTXContext;
27 typedef struct AVComplexFloat {
33 * Standard complex to complex FFT with sample data type AVComplexFloat.
34 * Scaling currently unsupported
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)
45 * Function pointer to a function to perform the transform.
47 * @note Using a different context than the one allocated during av_tx_init()
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
56 typedef void (*av_tx_fn)(AVTXContext *s, void *out, void *in, ptrdiff_t stride);
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.
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
71 * @return 0 on success, negative error code on failure
73 int av_tx_init(AVTXContext **ctx, av_tx_fn *tx, enum AVTXType type,
74 int inv, int len, const void *scale, uint64_t flags);
77 * Frees a context and sets ctx to NULL, does nothing when ctx == NULL
79 void av_tx_uninit(AVTXContext **ctx);
81 #endif /* AVUTIL_TX_H */