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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * copyright (c) 2012 Michael Niedermayer |
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| 3 | * |
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| 4 | * This file is part of FFmpeg. |
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| 5 | * |
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| 6 | * FFmpeg is free software; you can redistribute it and/or |
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| 7 | * modify it under the terms of the GNU Lesser General Public |
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| 8 | * License as published by the Free Software Foundation; either |
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| 9 | * version 2.1 of the License, or (at your option) any later version. |
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| 10 | * |
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| 11 | * FFmpeg is distributed in the hope that it will be useful, |
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| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | * Lesser General Public License for more details. |
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| 15 | * |
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| 16 | * You should have received a copy of the GNU Lesser General Public |
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| 17 | * License along with FFmpeg; if not, write to the Free Software |
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| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 19 | */ |
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| 20 | |||
| 21 | #include "common.h" |
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| 22 | |||
| 23 | |||
| 24 | /** |
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| 25 | * Quicksort |
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| 26 | * This sort is fast, and fully inplace but not stable and it is possible |
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| 27 | * to construct input that requires O(n^2) time but this is very unlikely to |
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| 28 | * happen with non constructed input. |
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| 29 | */ |
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| 30 | #define AV_QSORT(p, num, type, cmp) {\ |
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| 31 | void *stack[64][2];\ |
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| 32 | int sp= 1;\ |
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| 33 | stack[0][0] = p;\ |
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| 34 | stack[0][1] = (p)+(num)-1;\ |
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| 35 | while(sp){\ |
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| 36 | type *start= stack[--sp][0];\ |
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| 37 | type *end = stack[ sp][1];\ |
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| 38 | while(start < end){\ |
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| 39 | if(start < end-1) {\ |
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| 40 | int checksort=0;\ |
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| 41 | type *right = end-2;\ |
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| 42 | type *left = start+1;\ |
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| 43 | type *mid = start + ((end-start)>>1);\ |
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| 44 | if(cmp(start, end) > 0) {\ |
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| 45 | if(cmp( end, mid) > 0) FFSWAP(type, *start, *mid);\ |
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| 46 | else FFSWAP(type, *start, *end);\ |
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| 47 | }else{\ |
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| 48 | if(cmp(start, mid) > 0) FFSWAP(type, *start, *mid);\ |
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| 49 | else checksort= 1;\ |
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| 50 | }\ |
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| 51 | if(cmp(mid, end) > 0){ \ |
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| 52 | FFSWAP(type, *mid, *end);\ |
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| 53 | checksort=0;\ |
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| 54 | }\ |
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| 55 | if(start == end-2) break;\ |
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| 56 | FFSWAP(type, end[-1], *mid);\ |
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| 57 | while(left <= right){\ |
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| 58 | while(left<=right && cmp(left, end-1) < 0)\ |
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| 59 | left++;\ |
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| 60 | while(left<=right && cmp(right, end-1) > 0)\ |
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| 61 | right--;\ |
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| 62 | if(left <= right){\ |
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| 63 | FFSWAP(type, *left, *right);\ |
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| 64 | left++;\ |
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| 65 | right--;\ |
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| 66 | }\ |
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| 67 | }\ |
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| 68 | FFSWAP(type, end[-1], *left);\ |
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| 69 | if(checksort && (mid == left-1 || mid == left)){\ |
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| 70 | mid= start;\ |
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| 71 | while(mid |
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| 72 | mid++;\ |
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| 73 | if(mid==end)\ |
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| 74 | break;\ |
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| 75 | }\ |
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| 76 | if(end-left < left-start){\ |
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| 77 | stack[sp ][0]= start;\ |
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| 78 | stack[sp++][1]= right;\ |
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| 79 | start = left+1;\ |
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| 80 | }else{\ |
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| 81 | stack[sp ][0]= left+1;\ |
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| 82 | stack[sp++][1]= end;\ |
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| 83 | end = right;\ |
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| 84 | }\ |
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| 85 | }else{\ |
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| 86 | if(cmp(start, end) > 0)\ |
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| 87 | FFSWAP(type, *start, *end);\ |
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| 88 | break;\ |
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| 89 | }\ |
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| 90 | }\ |
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| 91 | }\ |
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| 92 | } |
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| 93 | |||
| 94 | /** |
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| 95 | * Merge sort, this sort requires a temporary buffer and is stable, its worst |
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| 96 | * case time is O(n log n) |
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| 97 | * @param p must be a lvalue pointer, this function may exchange it with tmp |
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| 98 | * @param tmp must be a lvalue pointer, this function may exchange it with p |
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| 99 | */ |
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| 100 | #define AV_MSORT(p, tmp, num, type, cmp) {\ |
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| 101 | unsigned i, j, step;\ |
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| 102 | for(step=1; step<(num); step+=step){\ |
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| 103 | for(i=0; i<(num); i+=2*step){\ |
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| 104 | unsigned a[2] = {i, i+step};\ |
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| 105 | unsigned end = FFMIN(i+2*step, (num));\ |
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| 106 | for(j=i; a[0] |
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| 107 | int idx= cmp(p+a[0], p+a[1]) > 0;\ |
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| 108 | tmp[j] = p[ a[idx]++ ];\ |
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| 109 | }\ |
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| 110 | if(a[0]>=i+step) a[0] = a[1];\ |
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| 111 | for(; j |
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| 112 | tmp[j] = p[ a[0]++ ];\ |
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| 113 | }\ |
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| 114 | }\ |
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| 115 | FFSWAP(type*, p, tmp);\ |
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| 116 | }\ |
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| 117 | } |