title: iOS open source build for armv7 , armv7s ,arm64
body: <p>I am developing an application for iOS device,
  and one of the requirement is to make use of libvpx <a href="http://www.webmproject.org" rel="nofollow">webM</a>, i could able to build it for armv7 architecture, but since has to be universal application, so this should also get it build for armv7s , arm64 architecture too, </p>
  
  <p>now need few clarification, </p>
  
  <ul>
  <li>Since libvpx doesn't have strong build support for arm64 and armv7s and it seems  arm64 has backward support, so is it sufficient to
  use armv7 library for arm64 and if this is the case, then what should
  be modify in the Xcode project settings,</li>
  <li>or I should keep Xcode project settings as it is, but should modify library configuration using lipo or any other build tool.</li>
  </ul>
  
  <p>In short, i want to know, if any open source which has standard ./configure , make etc... build support for arm7 being there, then how can it be used to support armv7s and arm64 bit architecture.  </p>