title: Converting protocol buffers to/from JSON in C, without generating C code
body: <p>I need to use <code>.desc</code> files to enable the reading of serialized protocol-buffer messages and their conversion to JSON (using jansson).  </p>
  
  <p>This is because the protocol-buffer message formats will change much more frequently than the C code.  The <code>.desc</code> files will be a runtime input to the executable.</p>
  
  <p>I've found <a href="https://github.com/Sannis/protobuf2json-c" rel="nofollow">https://github.com/Sannis/protobuf2json-c</a> but my reading of this is that it needs C code to be generated.  In particular the <code>ProtobufCMessage</code> needs to exist for the message being decoded, and I cannot see a way of making a ProtobufCMessage (from <code>/usr/include/google/protobuf-c/protobuf-c.h</code>) without generating C code.</p>
  
  <p>Have I missed something here, or will I need to write new code?</p>