title: Error while building PJSIP with FFMPEG storage size of 'dstFormat' isn't known
body: <p><strong>Building PJSIP for armeabi with FFMPEG gives me following output:</strong></p>
  
  <pre><code>../src/pjmedia/converter_libswscale.c: In function 'factory_create_converter':
  ../src/pjmedia/converter_libswscale.c:70:24: error: storage size of 'srcFormat' isn't known
   enum AVPixelFormat srcFormat, dstFormat;
                      ^
  </code></pre>
  
  <p>I've read many articles about problems with PixelFormat -> AVPixelFormat in newer versions of FFMPEG(Such as one i've built for PJSIP) - I got all of my pj sources updated according with AVPixelFormat.</p>
  
  <p><strong>Building environment:</strong></p>
  
  <p>Ubuntu 16.04 LTS 64bit running in VirtualBox</p>
  
  <p>PJSIP 2.6</p>
  
  <p>FFMPEG 3.0.9</p>
  
  <p><strong>Compiling PJSIP with flags:</strong></p>
  
  <p>#define PJMEDIA_HAS_VIDEO 1</p>
  
  <p>#define PJMEDIA_HAS_FFMPEG 1</p>
  
  <p><strong>NDK-flag:</strong></p>
  
  <p>--with-ffmpeg="${BASE_DIR}/ffmpeg-output"</p>
  
  <p><strong>ffmpeg-output folder contains these files:</strong></p>
  
  <ul>
  <li>libavcodec.so</li>
  <li>libavcodec.so.57</li>
  <li>libavcodec.so.57.24.102</li>
  <li>libavdevice.so</li>
  <li>libavdevice.so.57</li>
  <li>libavdevice.so.57.0.101</li>
  <li>libavfilter.so</li>
  <li>libavfilter.so.6</li>
  <li>libavfilter.so.6.31.100</li>
  <li>libavformat.so</li>
  <li>libavformat.so.57</li>
  <li>libavformat.so.57.25.100</li>
  <li>libavutil.so</li>
  <li>libavutil.so.55</li>
  <li>libavutil.so.55.17.103</li>
  <li>libpostproc.so</li>
  <li>libpostproc.so.54</li>
  <li>libpostproc.so.54.0.100</li>
  <li>libswresample.so</li>
  <li>libswresample.so.2</li>
  <li>libswresample.so.2.0.101</li>
  <li>libswscale.so</li>
  <li>libswscale.so.4</li>
  <li>libswscale.so.4.0.100</li>
  </ul>
  
  <p>Trying to build different versions of FFMPEG didn't work at all(Got the same error at the end)</p>
  
  <p>Any help will be appreciated.</p>
  
  <p><strong>UPD</strong>:
  Is there any strange stuff aboud AVPixelFormat in this part of compiler output related to ffmpeg:</p>
  
  <pre><code>checking ffmpeg packages...  libavdevice libavformat libavcodec libswscale libavutil
  checking for enum AVPixelFormat... no
  checking for v4l2_open in -lv4l2... no
  Checking if OpenH264 is disabled... yes
  Skipping Intel IPP settings (not wanted)
  </code></pre>
  
  <p>I mean the line says "checking for enum AVPixelFormat... no" - is there any flag I need to write to say to PJSIP "you have to work with AVPixelFormat"?</p>