| /* |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #ifndef AVUTIL_TX_H |
| #define AVUTIL_TX_H |
| |
| #include <stdint.h> |
| #include <stddef.h> |
| |
| typedef struct AVTXContext AVTXContext; |
| |
| typedef struct AVComplexFloat { |
| float re, im; |
| } AVComplexFloat; |
| |
| enum AVTXType { |
| /** |
| * Standard complex to complex FFT with sample data type AVComplexFloat. |
| * Scaling currently unsupported |
| */ |
| AV_TX_FLOAT_FFT = 0, |
| /** |
| * Standard MDCT with sample data type of float and a scale type of |
| * float. Length is the frame size, not the window size (which is 2x frame) |
| */ |
| AV_TX_FLOAT_MDCT = 1, |
| }; |
| |
| /** |
| * Function pointer to a function to perform the transform. |
| * |
| * @note Using a different context than the one allocated during av_tx_init() |
| * is not allowed. |
| * |
| * @param s the transform context |
| * @param out the output array |
| * @param in the input array |
| * @param stride the input or output stride (depending on transform direction) |
| * in bytes, currently implemented for all MDCT transforms |
| */ |
| typedef void (*av_tx_fn)(AVTXContext *s, void *out, void *in, ptrdiff_t stride); |
| |
| /** |
| * Initialize a transform context with the given configuration |
| * Currently power of two lengths from 4 to 131072 are supported, along with |
| * any length decomposable to a power of two and either 3, 5 or 15. |
| * |
| * @param ctx the context to allocate, will be NULL on error |
| * @param tx pointer to the transform function pointer to set |
| * @param type type the type of transform |
| * @param inv whether to do an inverse or a forward transform |
| * @param len the size of the transform in samples |
| * @param scale pointer to the value to scale the output if supported by type |
| * @param flags currently unused |
| * |
| * @return 0 on success, negative error code on failure |
| */ |
| int av_tx_init(AVTXContext **ctx, av_tx_fn *tx, enum AVTXType type, |
| int inv, int len, const void *scale, uint64_t flags); |
| |
| /** |
| * Frees a context and sets ctx to NULL, does nothing when ctx == NULL |
| */ |
| void av_tx_uninit(AVTXContext **ctx); |
| |
| #endif /* AVUTIL_TX_H */ |