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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /media/ffvpx/libavutil/qsort.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
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diff --git a/media/ffvpx/libavutil/qsort.h b/media/ffvpx/libavutil/qsort.h
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+/*
+ * copyright (c) 2012 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * 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_QSORT_H
+#define AVUTIL_QSORT_H
+
+#include "common.h"
+
+
+/**
+ * Quicksort
+ * This sort is fast, and fully inplace but not stable and it is possible
+ * to construct input that requires O(n^2) time but this is very unlikely to
+ * happen with non constructed input.
+ */
+#define AV_QSORT(p, num, type, cmp) do {\
+ void *stack[64][2];\
+ int sp= 1;\
+ stack[0][0] = p;\
+ stack[0][1] = (p)+(num)-1;\
+ while(sp){\
+ type *start= stack[--sp][0];\
+ type *end = stack[ sp][1];\
+ while(start < end){\
+ if(start < end-1) {\
+ int checksort=0;\
+ type *right = end-2;\
+ type *left = start+1;\
+ type *mid = start + ((end-start)>>1);\
+ if(cmp(start, end) > 0) {\
+ if(cmp( end, mid) > 0) FFSWAP(type, *start, *mid);\
+ else FFSWAP(type, *start, *end);\
+ }else{\
+ if(cmp(start, mid) > 0) FFSWAP(type, *start, *mid);\
+ else checksort= 1;\
+ }\
+ if(cmp(mid, end) > 0){ \
+ FFSWAP(type, *mid, *end);\
+ checksort=0;\
+ }\
+ if(start == end-2) break;\
+ FFSWAP(type, end[-1], *mid);\
+ while(left <= right){\
+ while(left<=right && cmp(left, end-1) < 0)\
+ left++;\
+ while(left<=right && cmp(right, end-1) > 0)\
+ right--;\
+ if(left <= right){\
+ FFSWAP(type, *left, *right);\
+ left++;\
+ right--;\
+ }\
+ }\
+ FFSWAP(type, end[-1], *left);\
+ if(checksort && (mid == left-1 || mid == left)){\
+ mid= start;\
+ while(mid<end && cmp(mid, mid+1) <= 0)\
+ mid++;\
+ if(mid==end)\
+ break;\
+ }\
+ if(end-left < left-start){\
+ stack[sp ][0]= start;\
+ stack[sp++][1]= right;\
+ start = left+1;\
+ }else{\
+ stack[sp ][0]= left+1;\
+ stack[sp++][1]= end;\
+ end = right;\
+ }\
+ }else{\
+ if(cmp(start, end) > 0)\
+ FFSWAP(type, *start, *end);\
+ break;\
+ }\
+ }\
+ }\
+} while (0)
+
+/**
+ * Merge sort, this sort requires a temporary buffer and is stable, its worst
+ * case time is O(n log n)
+ * @param p must be a lvalue pointer, this function may exchange it with tmp
+ * @param tmp must be a lvalue pointer, this function may exchange it with p
+ */
+#define AV_MSORT(p, tmp, num, type, cmp) do {\
+ unsigned i, j, step;\
+ for(step=1; step<(num); step+=step){\
+ for(i=0; i<(num); i+=2*step){\
+ unsigned a[2] = {i, i+step};\
+ unsigned end = FFMIN(i+2*step, (num));\
+ for(j=i; a[0]<i+step && a[1]<end; j++){\
+ int idx= cmp(p+a[0], p+a[1]) > 0;\
+ tmp[j] = p[ a[idx]++ ];\
+ }\
+ if(a[0]>=i+step) a[0] = a[1];\
+ for(; j<end; j++){\
+ tmp[j] = p[ a[0]++ ];\
+ }\
+ }\
+ FFSWAP(type*, p, tmp);\
+ }\
+} while (0)
+
+#endif /* AVUTIL_QSORT_H */