[FFmpeg-devel] [PATCH 1/2] lavu: add locale-independent sscanf implementation
Paul B Mahol
onemda at gmail.com
Mon Nov 12 21:32:56 EET 2018
Copied and adopted from musl implementation.
* converted all 'long double' to 'double'
* removed %m support
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavutil/Makefile | 1 +
libavutil/avsscanf.c | 971 +++++++++++++++++++++++++++++++++++++++++++
libavutil/avstring.c | 1 +
libavutil/avstring.h | 6 +
4 files changed, 979 insertions(+)
create mode 100644 libavutil/avsscanf.c
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 9ed24cfc82..27b548d7cf 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -94,6 +94,7 @@ OBJS = adler32.o \
aes_ctr.o \
audio_fifo.o \
avstring.o \
+ avsscanf.o \
base64.o \
blowfish.o \
bprint.o \
diff --git a/libavutil/avsscanf.c b/libavutil/avsscanf.c
new file mode 100644
index 0000000000..7c61b860ae
--- /dev/null
+++ b/libavutil/avsscanf.c
@@ -0,0 +1,971 @@
+/*
+ * Copyright (c) 2005-2014 Rich Felker, et al.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <float.h>
+
+#include "config.h"
+#include "common.h"
+#include "mem.h"
+#include "avassert.h"
+#include "avstring.h"
+#include "bprint.h"
+
+typedef struct FFFILE {
+ size_t buf_size;
+ unsigned char *buf;
+ unsigned char *rpos, *rend;
+ unsigned char *shend;
+ off_t shlim, shcnt;
+ void *cookie;
+ size_t (*read)(struct FFFILE *, unsigned char *, size_t);
+} FFFILE;
+
+#define SIZE_hh -2
+#define SIZE_h -1
+#define SIZE_def 0
+#define SIZE_l 1
+#define SIZE_L 2
+#define SIZE_ll 3
+
+#define shcnt(f) ((f)->shcnt + ((f)->rpos - (f)->buf))
+
+static int fftoread(FFFILE *f)
+{
+ f->rpos = f->rend = f->buf + f->buf_size;
+ return 0;
+}
+
+static size_t ffstring_read(FFFILE *f, unsigned char *buf, size_t len)
+{
+ char *src = f->cookie;
+ size_t k = len+256;
+ char *end = memchr(src, 0, k);
+
+ if (end) k = end-src;
+ if (k < len) len = k;
+ memcpy(buf, src, len);
+ f->rpos = (void *)(src+len);
+ f->rend = (void *)(src+k);
+ f->cookie = src+k;
+
+ return len;
+}
+
+static int ffuflow(FFFILE *f)
+{
+ unsigned char c;
+ if (!fftoread(f) && f->read(f, &c, 1)==1) return c;
+ return EOF;
+}
+
+static void ffshlim(FFFILE *f, off_t lim)
+{
+ f->shlim = lim;
+ f->shcnt = f->buf - f->rpos;
+ /* If lim is nonzero, rend must be a valid pointer. */
+ if (lim && f->rend - f->rpos > lim)
+ f->shend = f->rpos + lim;
+ else
+ f->shend = f->rend;
+}
+
+static int ffshgetc(FFFILE *f)
+{
+ int c;
+ off_t cnt = shcnt(f);
+ if (f->shlim && cnt >= f->shlim || (c=ffuflow(f)) < 0) {
+ f->shcnt = f->buf - f->rpos + cnt;
+ f->shend = 0;
+ return EOF;
+ }
+ cnt++;
+ if (f->shlim && f->rend - f->rpos > f->shlim - cnt)
+ f->shend = f->rpos + (f->shlim - cnt);
+ else
+ f->shend = f->rend;
+ f->shcnt = f->buf - f->rpos + cnt;
+ if (f->rpos[-1] != c) f->rpos[-1] = c;
+ return c;
+}
+
+#define shlim(f, lim) ffshlim((f), (lim))
+#define shgetc(f) (((f)->rpos != (f)->shend) ? *(f)->rpos++ : ffshgetc(f))
+#define shunget(f) ((f)->shend ? (void)(f)->rpos-- : (void)0)
+
+static const unsigned char table[] = { -1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1,
+ -1,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
+ 25,26,27,28,29,30,31,32,33,34,35,-1,-1,-1,-1,-1,
+ -1,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
+ 25,26,27,28,29,30,31,32,33,34,35,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+};
+
+static unsigned long long ffintscan(FFFILE *f, unsigned base, int pok, unsigned long long lim)
+{
+ const unsigned char *val = table+1;
+ int c, neg=0;
+ unsigned x;
+ unsigned long long y;
+ if (base > 36 || base == 1) {
+ errno = EINVAL;
+ return 0;
+ }
+ while (av_isspace((c=shgetc(f))));
+ if (c=='+' || c=='-') {
+ neg = -(c=='-');
+ c = shgetc(f);
+ }
+ if ((base == 0 || base == 16) && c=='0') {
+ c = shgetc(f);
+ if ((c|32)=='x') {
+ c = shgetc(f);
+ if (val[c]>=16) {
+ shunget(f);
+ if (pok) shunget(f);
+ else shlim(f, 0);
+ return 0;
+ }
+ base = 16;
+ } else if (base == 0) {
+ base = 8;
+ }
+ } else {
+ if (base == 0) base = 10;
+ if (val[c] >= base) {
+ shunget(f);
+ shlim(f, 0);
+ errno = EINVAL;
+ return 0;
+ }
+ }
+ if (base == 10) {
+ for (x=0; c-'0'<10U && x<=UINT_MAX/10-1; c=shgetc(f))
+ x = x*10 + (c-'0');
+ for (y=x; c-'0'<10U && y<=ULLONG_MAX/10 && 10*y<=ULLONG_MAX-(c-'0'); c=shgetc(f))
+ y = y*10 + (c-'0');
+ if (c-'0'>=10U) goto done;
+ } else if (!(base & base-1)) {
+ int bs = "\0\1\2\4\7\3\6\5"[(0x17*base)>>5&7];
+ for (x=0; val[c]<base && x<=UINT_MAX/32; c=shgetc(f))
+ x = x<<bs | val[c];
+ for (y=x; val[c]<base && y<=ULLONG_MAX>>bs; c=shgetc(f))
+ y = y<<bs | val[c];
+ } else {
+ for (x=0; val[c]<base && x<=UINT_MAX/36-1; c=shgetc(f))
+ x = x*base + val[c];
+ for (y=x; val[c]<base && y<=ULLONG_MAX/base && base*y<=ULLONG_MAX-val[c]; c=shgetc(f))
+ y = y*base + val[c];
+ }
+ if (val[c]<base) {
+ for (; val[c]<base; c=shgetc(f));
+ errno = ERANGE;
+ y = lim;
+ if (lim&1) neg = 0;
+ }
+done:
+ shunget(f);
+ if (y>=lim) {
+ if (!(lim&1) && !neg) {
+ errno = ERANGE;
+ return lim-1;
+ } else if (y>lim) {
+ errno = ERANGE;
+ return lim;
+ }
+ }
+ return (y^neg)-neg;
+}
+
+static long long scanexp(FFFILE *f, int pok)
+{
+ int c;
+ int x;
+ long long y;
+ int neg = 0;
+
+ c = shgetc(f);
+ if (c=='+' || c=='-') {
+ neg = (c=='-');
+ c = shgetc(f);
+ if (c-'0'>=10U && pok) shunget(f);
+ }
+ if (c-'0'>=10U) {
+ shunget(f);
+ return LLONG_MIN;
+ }
+ for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
+ x = 10*x + c-'0';
+ for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
+ y = 10*y + c-'0';
+ for (; c-'0'<10U; c = shgetc(f));
+ shunget(f);
+ return neg ? -y : y;
+}
+
+#define LD_B1B_DIG 2
+#define LD_B1B_MAX 9007199, 254740991
+#define KMAX 128
+#define MASK (KMAX-1)
+#define CONCAT2(x,y) x ## y
+#define CONCAT(x,y) CONCAT2(x,y)
+
+static double decfloat(FFFILE *f, int c, int bits, int emin, int sign, int pok)
+{
+ uint32_t x[KMAX];
+ static const uint32_t th[] = { LD_B1B_MAX };
+ int i, j, k, a, z;
+ long long lrp=0, dc=0;
+ long long e10=0;
+ int lnz = 0;
+ int gotdig = 0, gotrad = 0;
+ int rp;
+ int e2;
+ int emax = -emin-bits+3;
+ int denormal = 0;
+ double y;
+ double frac=0;
+ double bias=0;
+ static const int p10s[] = { 10, 100, 1000, 10000,
+ 100000, 1000000, 10000000, 100000000 };
+
+ j=0;
+ k=0;
+
+ /* Don't let leading zeros consume buffer space */
+ for (; c=='0'; c = shgetc(f)) gotdig=1;
+ if (c=='.') {
+ gotrad = 1;
+ for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
+ }
+
+ x[0] = 0;
+ for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
+ if (c == '.') {
+ if (gotrad) break;
+ gotrad = 1;
+ lrp = dc;
+ } else if (k < KMAX-3) {
+ dc++;
+ if (c!='0') lnz = dc;
+ if (j) x[k] = x[k]*10 + c-'0';
+ else x[k] = c-'0';
+ if (++j==9) {
+ k++;
+ j=0;
+ }
+ gotdig=1;
+ } else {
+ dc++;
+ if (c!='0') {
+ lnz = (KMAX-4)*9;
+ x[KMAX-4] |= 1;
+ }
+ }
+ }
+ if (!gotrad) lrp=dc;
+
+ if (gotdig && (c|32)=='e') {
+ e10 = scanexp(f, pok);
+ if (e10 == LLONG_MIN) {
+ if (pok) {
+ shunget(f);
+ } else {
+ shlim(f, 0);
+ return 0;
+ }
+ e10 = 0;
+ }
+ lrp += e10;
+ } else if (c>=0) {
+ shunget(f);
+ }
+ if (!gotdig) {
+ errno = EINVAL;
+ shlim(f, 0);
+ return 0;
+ }
+
+ /* Handle zero specially to avoid nasty special cases later */
+ if (!x[0]) return sign * 0.0;
+
+ /* Optimize small integers (w/no exponent) and over/under-flow */
+ if (lrp==dc && dc<10 && (bits>30 || x[0]>>bits==0))
+ return sign * (double)x[0];
+ if (lrp > -emin/2) {
+ errno = ERANGE;
+ return sign * DBL_MAX * DBL_MAX;
+ }
+ if (lrp < emin-2*DBL_MANT_DIG) {
+ errno = ERANGE;
+ return sign * DBL_MIN * DBL_MIN;
+ }
+
+ /* Align incomplete final B1B digit */
+ if (j) {
+ for (; j<9; j++) x[k]*=10;
+ k++;
+ j=0;
+ }
+
+ a = 0;
+ z = k;
+ e2 = 0;
+ rp = lrp;
+
+ /* Optimize small to mid-size integers (even in exp. notation) */
+ if (lnz<9 && lnz<=rp && rp < 18) {
+ if (rp == 9) return sign * (double)x[0];
+ if (rp < 9) return sign * (double)x[0] / p10s[8-rp];
+ int bitlim = bits-3*(int)(rp-9);
+ if (bitlim>30 || x[0]>>bitlim==0)
+ return sign * (double)x[0] * p10s[rp-10];
+ }
+
+ /* Drop trailing zeros */
+ for (; !x[z-1]; z--);
+
+ /* Align radix point to B1B digit boundary */
+ if (rp % 9) {
+ int rpm9 = rp>=0 ? rp%9 : rp%9+9;
+ int p10 = p10s[8-rpm9];
+ uint32_t carry = 0;
+ for (k=a; k!=z; k++) {
+ uint32_t tmp = x[k] % p10;
+ x[k] = x[k]/p10 + carry;
+ carry = 1000000000/p10 * tmp;
+ if (k==a && !x[k]) {
+ a = (a+1 & MASK);
+ rp -= 9;
+ }
+ }
+ if (carry) x[z++] = carry;
+ rp += 9-rpm9;
+ }
+
+ /* Upscale until desired number of bits are left of radix point */
+ while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[a]<th[0])) {
+ uint32_t carry = 0;
+ e2 -= 29;
+ for (k=(z-1 & MASK); ; k=(k-1 & MASK)) {
+ uint64_t tmp = ((uint64_t)x[k] << 29) + carry;
+ if (tmp > 1000000000) {
+ carry = tmp / 1000000000;
+ x[k] = tmp % 1000000000;
+ } else {
+ carry = 0;
+ x[k] = tmp;
+ }
+ if (k==(z-1 & MASK) && k!=a && !x[k]) z = k;
+ if (k==a) break;
+ }
+ if (carry) {
+ rp += 9;
+ a = (a-1 & MASK);
+ if (a == z) {
+ z = (z-1 & MASK);
+ x[z-1 & MASK] |= x[z];
+ }
+ x[a] = carry;
+ }
+ }
+
+ /* Downscale until exactly number of bits are left of radix point */
+ for (;;) {
+ uint32_t carry = 0;
+ int sh = 1;
+ for (i=0; i<LD_B1B_DIG; i++) {
+ k = (a+i & MASK);
+ if (k == z || x[k] < th[i]) {
+ i=LD_B1B_DIG;
+ break;
+ }
+ if (x[a+i & MASK] > th[i]) break;
+ }
+ if (i==LD_B1B_DIG && rp==9*LD_B1B_DIG) break;
+ /* FIXME: find a way to compute optimal sh */
+ if (rp > 9+9*LD_B1B_DIG) sh = 9;
+ e2 += sh;
+ for (k=a; k!=z; k=(k+1 & MASK)) {
+ uint32_t tmp = x[k] & (1<<sh)-1;
+ x[k] = (x[k]>>sh) + carry;
+ carry = (1000000000>>sh) * tmp;
+ if (k==a && !x[k]) {
+ a = (a+1 & MASK);
+ i--;
+ rp -= 9;
+ }
+ }
+ if (carry) {
+ if ((z+1 & MASK) != a) {
+ x[z] = carry;
+ z = (z+1 & MASK);
+ } else x[z-1 & MASK] |= 1;
+ }
+ }
+
+ /* Assemble desired bits into floating point variable */
+ for (y=i=0; i<LD_B1B_DIG; i++) {
+ if ((a+i & MASK)==z) x[(z=(z+1 & MASK))-1] = 0;
+ y = 1000000000.0L * y + x[a+i & MASK];
+ }
+
+ y *= sign;
+
+ /* Limit precision for denormal results */
+ if (bits > DBL_MANT_DIG+e2-emin) {
+ bits = DBL_MANT_DIG+e2-emin;
+ if (bits<0) bits=0;
+ denormal = 1;
+ }
+
+ /* Calculate bias term to force rounding, move out lower bits */
+ if (bits < DBL_MANT_DIG) {
+ bias = copysignl(scalbn(1, 2*DBL_MANT_DIG-bits-1), y);
+ frac = fmodl(y, scalbn(1, DBL_MANT_DIG-bits));
+ y -= frac;
+ y += bias;
+ }
+
+ /* Process tail of decimal input so it can affect rounding */
+ if ((a+i & MASK) != z) {
+ uint32_t t = x[a+i & MASK];
+ if (t < 500000000 && (t || (a+i+1 & MASK) != z))
+ frac += 0.25*sign;
+ else if (t > 500000000)
+ frac += 0.75*sign;
+ else if (t == 500000000) {
+ if ((a+i+1 & MASK) == z)
+ frac += 0.5*sign;
+ else
+ frac += 0.75*sign;
+ }
+ if (DBL_MANT_DIG-bits >= 2 && !fmodl(frac, 1))
+ frac++;
+ }
+
+ y += frac;
+ y -= bias;
+
+ if ((e2+DBL_MANT_DIG & INT_MAX) > emax-5) {
+ if (fabs(y) >= CONCAT(0x1p, DBL_MANT_DIG)) {
+ if (denormal && bits==DBL_MANT_DIG+e2-emin)
+ denormal = 0;
+ y *= 0.5;
+ e2++;
+ }
+ if (e2+DBL_MANT_DIG>emax || (denormal && frac))
+ errno = ERANGE;
+ }
+
+ return scalbnl(y, e2);
+}
+
+static double hexfloat(FFFILE *f, int bits, int emin, int sign, int pok)
+{
+ uint32_t x = 0;
+ double y = 0;
+ double scale = 1;
+ double bias = 0;
+ int gottail = 0, gotrad = 0, gotdig = 0;
+ long long rp = 0;
+ long long dc = 0;
+ long long e2 = 0;
+ int d;
+ int c;
+
+ c = shgetc(f);
+
+ /* Skip leading zeros */
+ for (; c=='0'; c = shgetc(f))
+ gotdig = 1;
+
+ if (c=='.') {
+ gotrad = 1;
+ c = shgetc(f);
+ /* Count zeros after the radix point before significand */
+ for (rp=0; c=='0'; c = shgetc(f), rp--) gotdig = 1;
+ }
+
+ for (; c-'0'<10U || (c|32)-'a'<6U || c=='.'; c = shgetc(f)) {
+ if (c=='.') {
+ if (gotrad) break;
+ rp = dc;
+ gotrad = 1;
+ } else {
+ gotdig = 1;
+ if (c > '9') d = (c|32)+10-'a';
+ else d = c-'0';
+ if (dc<8) {
+ x = x*16 + d;
+ } else if (dc < DBL_MANT_DIG/4+1) {
+ y += d*(scale/=16);
+ } else if (d && !gottail) {
+ y += 0.5*scale;
+ gottail = 1;
+ }
+ dc++;
+ }
+ }
+ if (!gotdig) {
+ shunget(f);
+ if (pok) {
+ shunget(f);
+ if (gotrad) shunget(f);
+ } else {
+ shlim(f, 0);
+ }
+ return sign * 0.0;
+ }
+ if (!gotrad) rp = dc;
+ while (dc<8) x *= 16, dc++;
+ if ((c|32)=='p') {
+ e2 = scanexp(f, pok);
+ if (e2 == LLONG_MIN) {
+ if (pok) {
+ shunget(f);
+ } else {
+ shlim(f, 0);
+ return 0;
+ }
+ e2 = 0;
+ }
+ } else {
+ shunget(f);
+ }
+ e2 += 4*rp - 32;
+
+ if (!x) return sign * 0.0;
+ if (e2 > -emin) {
+ errno = ERANGE;
+ return sign * DBL_MAX * DBL_MAX;
+ }
+ if (e2 < emin-2*DBL_MANT_DIG) {
+ errno = ERANGE;
+ return sign * DBL_MIN * DBL_MIN;
+ }
+
+ while (x < 0x80000000) {
+ if (y>=0.5) {
+ x += x + 1;
+ y += y - 1;
+ } else {
+ x += x;
+ y += y;
+ }
+ e2--;
+ }
+
+ if (bits > 32+e2-emin) {
+ bits = 32+e2-emin;
+ if (bits<0) bits=0;
+ }
+
+ if (bits < DBL_MANT_DIG)
+ bias = copysignl(scalbn(1, 32+DBL_MANT_DIG-bits-1), sign);
+
+ if (bits<32 && y && !(x&1)) x++, y=0;
+
+ y = bias + sign*(double)x + sign*y;
+ y -= bias;
+
+ if (!y) errno = ERANGE;
+
+ return scalbnl(y, e2);
+}
+
+static double fffloatscan(FFFILE *f, int prec, int pok)
+{
+ int sign = 1;
+ size_t i;
+ int bits;
+ int emin;
+ int c;
+
+ switch (prec) {
+ case 0:
+ bits = FLT_MANT_DIG;
+ emin = FLT_MIN_EXP-bits;
+ break;
+ case 1:
+ bits = DBL_MANT_DIG;
+ emin = DBL_MIN_EXP-bits;
+ break;
+ case 2:
+ bits = DBL_MANT_DIG;
+ emin = DBL_MIN_EXP-bits;
+ break;
+ default:
+ return 0;
+ }
+
+ while (av_isspace((c = shgetc(f))));
+
+ if (c=='+' || c=='-') {
+ sign -= 2*(c=='-');
+ c = shgetc(f);
+ }
+
+ for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
+ if (i<7) c = shgetc(f);
+ if (i==3 || i==8 || (i>3 && pok)) {
+ if (i!=8) {
+ shunget(f);
+ if (pok) for (; i>3; i--) shunget(f);
+ }
+ return sign * INFINITY;
+ }
+ if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
+ if (i<2) c = shgetc(f);
+ if (i==3) {
+ if (shgetc(f) != '(') {
+ shunget(f);
+ return NAN;
+ }
+ for (i=1; ; i++) {
+ c = shgetc(f);
+ if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
+ continue;
+ if (c==')') return NAN;
+ shunget(f);
+ if (!pok) {
+ errno = EINVAL;
+ shlim(f, 0);
+ return 0;
+ }
+ while (i--) shunget(f);
+ return NAN;
+ }
+ return NAN;
+ }
+
+ if (i) {
+ shunget(f);
+ errno = EINVAL;
+ shlim(f, 0);
+ return 0;
+ }
+
+ if (c=='0') {
+ c = shgetc(f);
+ if ((c|32) == 'x')
+ return hexfloat(f, bits, emin, sign, pok);
+ shunget(f);
+ c = '0';
+ }
+
+ return decfloat(f, c, bits, emin, sign, pok);
+}
+
+static void *arg_n(va_list ap, unsigned int n)
+{
+ void *p;
+ unsigned int i;
+ va_list ap2;
+ va_copy(ap2, ap);
+ for (i=n; i>1; i--) va_arg(ap2, void *);
+ p = va_arg(ap2, void *);
+ va_end(ap2);
+ return p;
+}
+
+static void store_int(void *dest, int size, unsigned long long i)
+{
+ if (!dest) return;
+ switch (size) {
+ case SIZE_hh:
+ *(char *)dest = i;
+ break;
+ case SIZE_h:
+ *(short *)dest = i;
+ break;
+ case SIZE_def:
+ *(int *)dest = i;
+ break;
+ case SIZE_l:
+ *(long *)dest = i;
+ break;
+ case SIZE_ll:
+ *(long long *)dest = i;
+ break;
+ }
+}
+
+static int ff_vfscanf(FFFILE *f, const char *fmt, va_list ap)
+{
+ int width;
+ int size;
+ int base;
+ const unsigned char *p;
+ int c, t;
+ char *s;
+ void *dest=NULL;
+ int invert;
+ int matches=0;
+ unsigned long long x;
+ double y;
+ off_t pos = 0;
+ unsigned char scanset[257];
+ size_t i;
+
+ for (p=(const unsigned char *)fmt; *p; p++) {
+
+ if (av_isspace(*p)) {
+ while (av_isspace(p[1])) p++;
+ shlim(f, 0);
+ while (av_isspace(shgetc(f)));
+ shunget(f);
+ pos += shcnt(f);
+ continue;
+ }
+ if (*p != '%' || p[1] == '%') {
+ shlim(f, 0);
+ if (*p == '%') {
+ p++;
+ while (av_isspace((c=shgetc(f))));
+ } else {
+ c = shgetc(f);
+ }
+ if (c!=*p) {
+ shunget(f);
+ if (c<0) goto input_fail;
+ goto match_fail;
+ }
+ pos += shcnt(f);
+ continue;
+ }
+
+ p++;
+ if (*p=='*') {
+ dest = 0; p++;
+ } else if (av_isdigit(*p) && p[1]=='$') {
+ dest = arg_n(ap, *p-'0'); p+=2;
+ } else {
+ dest = va_arg(ap, void *);
+ }
+
+ for (width=0; av_isdigit(*p); p++) {
+ width = 10*width + *p - '0';
+ }
+
+ if (*p=='m') {
+ s = 0;
+ p++;
+ }
+
+ size = SIZE_def;
+ switch (*p++) {
+ case 'h':
+ if (*p == 'h') p++, size = SIZE_hh;
+ else size = SIZE_h;
+ break;
+ case 'l':
+ if (*p == 'l') p++, size = SIZE_ll;
+ else size = SIZE_l;
+ break;
+ case 'j':
+ size = SIZE_ll;
+ break;
+ case 'z':
+ case 't':
+ size = SIZE_l;
+ break;
+ case 'L':
+ size = SIZE_L;
+ break;
+ case 'd': case 'i': case 'o': case 'u': case 'x':
+ case 'a': case 'e': case 'f': case 'g':
+ case 'A': case 'E': case 'F': case 'G': case 'X':
+ case 's': case 'c': case '[':
+ case 'S': case 'C':
+ case 'p': case 'n':
+ p--;
+ break;
+ default:
+ goto fmt_fail;
+ }
+
+ t = *p;
+
+ /* C or S */
+ if ((t&0x2f) == 3) {
+ t |= 32;
+ size = SIZE_l;
+ }
+
+ switch (t) {
+ case 'c':
+ if (width < 1) width = 1;
+ case '[':
+ break;
+ case 'n':
+ store_int(dest, size, pos);
+ /* do not increment match count, etc! */
+ continue;
+ default:
+ shlim(f, 0);
+ while (av_isspace(shgetc(f)));
+ shunget(f);
+ pos += shcnt(f);
+ }
+
+ shlim(f, width);
+ if (shgetc(f) < 0) goto input_fail;
+ shunget(f);
+
+ switch (t) {
+ case 's':
+ case 'c':
+ case '[':
+ if (t == 'c' || t == 's') {
+ memset(scanset, -1, sizeof scanset);
+ scanset[0] = 0;
+ if (t == 's') {
+ scanset[1 + '\t'] = 0;
+ scanset[1 + '\n'] = 0;
+ scanset[1 + '\v'] = 0;
+ scanset[1 + '\f'] = 0;
+ scanset[1 + '\r'] = 0;
+ scanset[1 + ' ' ] = 0;
+ }
+ } else {
+ if (*++p == '^') p++, invert = 1;
+ else invert = 0;
+ memset(scanset, invert, sizeof scanset);
+ scanset[0] = 0;
+ if (*p == '-') p++, scanset[1+'-'] = 1-invert;
+ else if (*p == ']') p++, scanset[1+']'] = 1-invert;
+ for (; *p != ']'; p++) {
+ if (!*p) goto fmt_fail;
+ if (*p=='-' && p[1] && p[1] != ']')
+ for (c=p++[-1]; c<*p; c++)
+ scanset[1+c] = 1-invert;
+ scanset[1+*p] = 1-invert;
+ }
+ }
+ s = 0;
+ i = 0;
+ if ((s = dest)) {
+ while (scanset[(c=shgetc(f))+1])
+ s[i++] = c;
+ } else {
+ while (scanset[(c=shgetc(f))+1]);
+ }
+ shunget(f);
+ if (!shcnt(f)) goto match_fail;
+ if (t == 'c' && shcnt(f) != width) goto match_fail;
+ if (t != 'c') {
+ if (s) s[i] = 0;
+ }
+ break;
+ case 'p':
+ case 'X':
+ case 'x':
+ base = 16;
+ goto int_common;
+ case 'o':
+ base = 8;
+ goto int_common;
+ case 'd':
+ case 'u':
+ base = 10;
+ goto int_common;
+ case 'i':
+ base = 0;
+int_common:
+ x = ffintscan(f, base, 0, ULLONG_MAX);
+ if (!shcnt(f))
+ goto match_fail;
+ if (t=='p' && dest)
+ *(void **)dest = (void *)(uintptr_t)x;
+ else
+ store_int(dest, size, x);
+ break;
+ case 'a': case 'A':
+ case 'e': case 'E':
+ case 'f': case 'F':
+ case 'g': case 'G':
+ y = fffloatscan(f, size, 0);
+ if (!shcnt(f))
+ goto match_fail;
+ if (dest) {
+ switch (size) {
+ case SIZE_def:
+ *(float *)dest = y;
+ break;
+ case SIZE_l:
+ *(double *)dest = y;
+ break;
+ case SIZE_L:
+ *(double *)dest = y;
+ break;
+ }
+ }
+ break;
+ }
+
+ pos += shcnt(f);
+ if (dest) matches++;
+ }
+ if (0) {
+fmt_fail:
+input_fail:
+ if (!matches) matches--;
+ }
+match_fail:
+ return matches;
+}
+
+static int ff_vsscanf(const char *s, const char *fmt, va_list ap)
+{
+ FFFILE f = {
+ .buf = (void *)s, .cookie = (void *)s,
+ .read = ffstring_read,
+ };
+
+ return ff_vfscanf(&f, fmt, ap);
+}
+
+int av_sscanf(const char *string, const char *format, ...)
+{
+ int ret;
+ va_list ap;
+ va_start(ap, format);
+ ret = ff_vsscanf(string, format, ap);
+ va_end(ap);
+ return ret;
+}
diff --git a/libavutil/avstring.c b/libavutil/avstring.c
index f03dd25141..c3f2ce4604 100644
--- a/libavutil/avstring.c
+++ b/libavutil/avstring.c
@@ -30,6 +30,7 @@
#include "avassert.h"
#include "avstring.h"
#include "bprint.h"
+#include "float.h"
int av_strstart(const char *str, const char *pfx, const char **ptr)
{
diff --git a/libavutil/avstring.h b/libavutil/avstring.h
index 04d2695640..37dd4e2da0 100644
--- a/libavutil/avstring.h
+++ b/libavutil/avstring.h
@@ -400,6 +400,12 @@ int av_utf8_decode(int32_t *codep, const uint8_t **bufp, const uint8_t *buf_end,
*/
int av_match_list(const char *name, const char *list, char separator);
+/**
+ * See libc sscanf manual for more information.
+ * Locale-independent sscanf implementation.
+ */
+int av_sscanf(const char *string, const char *format, ...);
+
/**
* @}
*/
--
2.17.1
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