VC使用mingw32编译ffmpeg静态库所需文件(一),ffmpegshim.c

哈哈，这是我从一些项目里面看到的，这些函数是ffmpeg.a缺少的函数。估计大家会用得上.

当然我移植的的项目都不需要这些，因为我是用VC编译，所以不存在缺少mingw32里面的函数.

// ffmpegshim.c
// this file is part of Context Free
// ---------------------
// Copyright (C) 2012 John Horigan - john@glyphic.com
// Copyright (C) 2000 Free Software Foundation, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// John Horigan can be contacted at john@glyphic.com or at
// John Horigan, 1209 Villa St., Mountain View, CA 94041-1123, USA
//
//

#define WIN32_LEAN_AND_MEAN
#define _CRT_SECURE_NO_WARNINGS

#include <windows.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>
#include <math.h>

int __cdecl __mingw_vsnprintf(
     char *buffer,
     size_t count,
     const char *format,
     va_list argptr
)
{
    return vsnprintf_s(buffer, count, _TRUNCATE, format, argptr);
}

int __cdecl __ms_vsnprintf(
     char *buffer,
     size_t count,
     const char *format,
     va_list argptr
)
{
    return vsnprintf_s(buffer, count, _TRUNCATE, format, argptr);
}

int __cdecl __mingw_vfprintf(
     FILE *stream,
     const char *format,
     va_list argptr
)
{
    return vfprintf_s(stream, format, argptr);
}

int __cdecl __mingw_vsprintf (char * s, const char * format, va_list arg )
{
	return vsprintf (s, format, arg );
}

#if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
#else
  #define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
#endif
 
struct timezone
{
    int  tz_minuteswest; /* minutes W of Greenwich */
    int  tz_dsttime;     /* type of dst correction */
};
struct timeval {
    long tv_sec;
    long tv_usec;
};

int __cdecl gettimeofday(
     struct timeval  *tv,
     struct timezone *tz
)
{
    FILETIME ft;
    unsigned __int64 tmpres = 0;
    static int tzflag;

    if (NULL != tv) {
        GetSystemTimeAsFileTime(&ft);

        tmpres |= ft.dwHighDateTime;
        tmpres <<= 32;
        tmpres |= ft.dwLowDateTime;

        /*converting file time to unix epoch*/
        tmpres -= DELTA_EPOCH_IN_MICROSECS;
        tmpres /= 10;  /*convert into microseconds*/
        tv->tv_sec = (long)(tmpres / 1000000UL);
        tv->tv_usec = (long)(tmpres % 1000000UL);
    }

    if (NULL != tz) {
        int i;
        long l = 0;
        if (!tzflag) {
            _tzset();
            tzflag++;
        }
        _get_timezone(&l);
        tz->tz_minuteswest = l / 60;
        _get_daylight(&i);
        tz->tz_dsttime = i;
    }

    return 0;
}

int __cdecl usleep(
     unsigned int useconds
)
{
    if(useconds == 0)
        return 0;

    if(useconds >= 1000000)
        return EINVAL;

    Sleep((useconds + 999) / 1000);

    return 0;
}

double __cdecl __strtod(
     const char *nptr,
     char **endptr
)
{
    return strtod(nptr, endptr);
}

double __cdecl trunc(
     double n
)
{
    return n > 0.0 ? floor(n) : ceil(n);
}

int __cdecl __mingw_vsscanf(
     const char *s,
     const char *fmt,
     va_list ap
)
{
    void *a[5];
    int i;
    for (i=0; i < sizeof(a)/sizeof(a[0]); i++)
        a[i] = va_arg(ap, void *);
    return sscanf(s, fmt, a[0], a[1], a[2], a[3], a[4]);
}

unsigned __int64 __cdecl udivmodsi4(
     unsigned __int64 num,
     unsigned __int64 den,
     int modwanted
)
{
    unsigned __int64 bit = 1;
    unsigned __int64 res = 0;

    while (den < num && bit && !(den & (1L<<31))) {
        den <<=1;
        bit <<=1;
    }
    while (bit) {
        if (num >= den) {
            num -= den;
            res |= bit;
        }
        bit >>=1;
        den >>=1;
    }
    return modwanted ? num : res;
}

__int64 __cdecl __divdi3(
     __int64 a,
     __int64 b
)
{
    int neg = 0;
    __int64 res;

    if (a < 0) {
        a = -a;
        neg = !neg;
    }

    if (b < 0) {
        b = -b;
        neg = !neg;
    }

    res = udivmodsi4(a, b, 0);

    if (neg)
        res = -res;

    return res;
}

__int64 __cdecl __moddi3(
     __int64 a,
     __int64 b
)
{
    int neg = 0;
    __int64 res;

    if (a < 0) {
        a = -a;
        neg = 1;
    }

    if (b < 0)
        b = -b;

    res = udivmodsi4(a, b, 1);

    if (neg)
        res = -res;

    return res;
}

unsigned __int64 __cdecl __udivdi3(
     unsigned __int64 a,
     unsigned __int64 b
)
{
    return udivmodsi4 (a, b, 0);
}

unsigned __int64 __cdecl __umoddi3(
     unsigned __int64 a,
     unsigned __int64 b
)
{
    return udivmodsi4 (a, b, 1);
}

ios:http://blog.csdn.net/weinyzhou/article/details/8091688

android:http://blog.csdn.net/weinyzhou/article/details/7723673

ffmpeg vc移植项目,支持ffmpeg 代码VC调试:http://blog.csdn.net/weinyzhou/article/details/7559205

以上项目，都是付费，需要的用户可以联系.

发布自:http://blog.csdn.net/weinyzhou/article/details/8120005