ffmpeg linux-atomic-64bit.c:59: error: undefined reference to '__write'

今天编译ffmpeg出现如下错误：
linux-atomic-64bit.c:59: error: undefined reference to '__write'查看了网上http://code.google.com/p/android/issues/detail?id=41297  在ndk4.6上有这个bug，不过现在修复了，没有看到这篇文章之前我是将4.6该为4.4.3编译通过的，通过也可以

r8d has the fix:
/d/android-ndk-r8d/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi-gcc
 atomic64.c --sysroot=/d/android-ndk-r8d/platforms/android-9/arch-arm/ -march=armv7-a
Note that 64-bit atomic needs either new dmb instruction or calling into kernel helper.
In armv7 the 64-bit atomic is ininlined with dmb, while in armv5 it call into kernel helper.
 The helper check kernel version and call __write if kernel version is low.  ie,
you need to supply your __write funciton for it to link.