Rename ffmpeg-4.2-fit to ffmpeg-4-fit

trunk/3rdparty/ffmpeg-4-fit/libavutil/qsort.h

@@ -0,0 +1,122 @@
+/*
+ * 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 */