Add Low Delay MPEG Surround to the enum of MPEG-4 Audio Object Types.

Originally committed as revision 20510 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mpeg4audio.h

@@ -92,6 +92,7 @@ enum AudioObjectType {
     AOT_SMR_MAIN,              ///< N                       Symbolic Music Representation Main
     AOT_USAC_NOSBR,            ///< N                       Unified Speech and Audio Coding (no SBR)
     AOT_SAOC,                  ///< N                       Spatial Audio Object Coding
+    AOT_LD_SURROUND,           ///< N                       Low Delay MPEG Surround
     AOT_USAC             = 45, ///< N                       Unified Speech and Audio Coding
 };