| 1 | /* |
| 2 | * Copyright (c) 2012 |
| 3 | * MIPS Technologies, Inc., California. |
| 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 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its |
| 14 | * contributors may be used to endorse or promote products derived from |
| 15 | * this software without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | * |
| 29 | * Author: Nedeljko Babic (nbabic@mips.com) |
| 30 | * |
| 31 | * This file is part of FFmpeg. |
| 32 | * |
| 33 | * FFmpeg is free software; you can redistribute it and/or |
| 34 | * modify it under the terms of the GNU Lesser General Public |
| 35 | * License as published by the Free Software Foundation; either |
| 36 | * version 2.1 of the License, or (at your option) any later version. |
| 37 | * |
| 38 | * FFmpeg is distributed in the hope that it will be useful, |
| 39 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 40 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 41 | * Lesser General Public License for more details. |
| 42 | * |
| 43 | * You should have received a copy of the GNU Lesser General Public |
| 44 | * License along with FFmpeg; if not, write to the Free Software |
| 45 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 46 | */ |
| 47 | |
| 48 | #ifndef AVUTIL_FIXED_DSP_H |
| 49 | #define AVUTIL_FIXED_DSP_H |
| 50 | |
| 51 | #include <stdint.h> |
| 52 | #include "attributes.h" |
| 53 | #include "common.h" |
| 54 | #include "libavcodec/mathops.h" |
| 55 | |
| 56 | typedef struct AVFixedDSPContext { |
| 57 | /** |
| 58 | * Overlap/add with window function. |
| 59 | * Used primarily by MDCT-based audio codecs. |
| 60 | * Source and destination vectors must overlap exactly or not at all. |
| 61 | * |
| 62 | * @param dst result vector |
| 63 | * constraints: 16-byte aligned |
| 64 | * @param src0 first source vector |
| 65 | * constraints: 16-byte aligned |
| 66 | * @param src1 second source vector |
| 67 | * constraints: 16-byte aligned |
| 68 | * @param win half-window vector |
| 69 | * constraints: 16-byte aligned |
| 70 | * @param len length of vector |
| 71 | * constraints: multiple of 4 |
| 72 | * @param bits scaling parameter |
| 73 | * |
| 74 | */ |
| 75 | void (*vector_fmul_window_scaled)(int16_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len, uint8_t bits); |
| 76 | |
| 77 | /** |
| 78 | * Overlap/add with window function. |
| 79 | * Used primarily by MDCT-based audio codecs. |
| 80 | * Source and destination vectors must overlap exactly or not at all. |
| 81 | * |
| 82 | * @param dst result vector |
| 83 | * constraints: 32-byte aligned |
| 84 | * @param src0 first source vector |
| 85 | * constraints: 16-byte aligned |
| 86 | * @param src1 second source vector |
| 87 | * constraints: 16-byte aligned |
| 88 | * @param win half-window vector |
| 89 | * constraints: 16-byte aligned |
| 90 | * @param len length of vector |
| 91 | * constraints: multiple of 4 |
| 92 | */ |
| 93 | void (*vector_fmul_window)(int32_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len); |
| 94 | |
| 95 | } AVFixedDSPContext; |
| 96 | |
| 97 | /** |
| 98 | * Allocate and initialize a fixed DSP context. |
| 99 | * note: should be freed with a av_free call when no longer needed. |
| 100 | * |
| 101 | * @param strict setting to non-zero avoids using functions which may not be IEEE-754 compliant |
| 102 | */ |
| 103 | AVFixedDSPContext * avpriv_alloc_fixed_dsp(int strict); |
| 104 | |
| 105 | /** |
| 106 | * Calculate the square root |
| 107 | * |
| 108 | * @param x input fixed point number |
| 109 | * |
| 110 | * @param bits format of fixed point number (32 - bits).bits |
| 111 | * |
| 112 | * note: input is normalized to (0, 1) fixed point value |
| 113 | */ |
| 114 | |
| 115 | static av_always_inline int fixed_sqrt(int x, int bits) |
| 116 | { |
| 117 | int retval, bit_mask, guess, square, i; |
| 118 | int64_t accu; |
| 119 | int shift1 = 30 - bits; |
| 120 | int shift2 = bits - 15; |
| 121 | |
| 122 | if (shift1 > 0) retval = ff_sqrt(x << shift1); |
| 123 | else retval = ff_sqrt(x >> -shift1); |
| 124 | |
| 125 | if (shift2 > 0) { |
| 126 | retval = retval << shift2; |
| 127 | bit_mask = (1 << (shift2 - 1)); |
| 128 | |
| 129 | for (i=0; i<shift2; i++){ |
| 130 | guess = retval + bit_mask; |
| 131 | accu = (int64_t)guess * guess; |
| 132 | square = (int)((accu + bit_mask) >> bits); |
| 133 | if (x >= square) |
| 134 | retval += bit_mask; |
| 135 | bit_mask >>= 1; |
| 136 | } |
| 137 | |
| 138 | } |
| 139 | else retval >>= (-shift2); |
| 140 | |
| 141 | return retval; |
| 142 | } |
| 143 | |
| 144 | #endif /* AVUTIL_FIXED_DSP_H */ |