command=strprintf("ffmpeg -ss 00:00:00.%d -i \"%s\" -an -f image2pipe -vcodec ppm -\n",frame,filename.c_str());
command=strprintf("ffmpeg -ss 00:00:00.%d -i \"%s\" -an -f image2pipe -vcodec ppm -\n",frame,filename.c_str());
file=popen(command.c_str(),POPEN_BINARY_READ_TYPE);
#elif defined(UNIX_PIPE_TO_PROCESSES)
int p[2];
file=popen(command.c_str(),POPEN_BINARY_READ_TYPE);
#elif defined(UNIX_PIPE_TO_PROCESSES)
int p[2];