Re #1134 (misc fixes): fixed various doxygen warnings, as well as added overview section in pjmedia documentation

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@3327 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjmedia/include/pjmedia-codec/amr_helper.h b/pjmedia/include/pjmedia-codec/amr_helper.h
index 8cc232e..e8df0a0 100644
--- a/pjmedia/include/pjmedia-codec/amr_helper.h
+++ b/pjmedia/include/pjmedia-codec/amr_helper.h
@@ -597,7 +597,7 @@
 
 
 /**
- * This structure describes AMR frame info, to be fitted into @pjmedia_frame 
+ * This structure describes AMR frame info, to be fitted into #pjmedia_frame
  * bit info.
  */
 #pragma pack(1)
@@ -712,9 +712,8 @@
  *   'setting' by setting/resetting field 'reorder'.
  * - align left the start bit (make the start_bit to be 0).
  *
- * @param amr_nb    Set PJ_TRUE for AMR-NB and PJ_FALSE for AMR-WB.
  * @param in	    Input frame.
- * @param setting   Settings, see @pjmedia_codec_amr_pack_setting.
+ * @param setting   Settings, see #pjmedia_codec_amr_pack_setting.
  * @param out	    Output frame.
  *
  * @return	    PJ_SUCCESS on success.
@@ -852,7 +851,7 @@
  *
  * @param frames    AMR frames to be packed.
  * @param nframes   Number of frames to be packed.
- * @param setting   Settings, see @pjmedia_codec_amr_pack_setting.
+ * @param setting   Settings, see #pjmedia_codec_amr_pack_setting.
  * @param pkt	    Payload.
  * @param pkt_size  Payload size, as input this specifies payload maximum size,
  *		    as output this specifies payload packed size.
@@ -1069,7 +1068,7 @@
  * @param pkt	    Payload.
  * @param pkt_size  Payload size.
  * @param ts	    Base timestamp.
- * @param setting   Settings, see @pjmedia_codec_amr_pack_setting.
+ * @param setting   Settings, see #pjmedia_codec_amr_pack_setting.
  * @param frames    Frames parsed.
  * @param nframes   Number of frames parsed.
  * @param cmr	    Change Mode Request message for local encoder.