Documentation update for AMV audio decoder

Originally committed as revision 10609 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -95,6 +95,7 @@ version <next>
 - Matroska muxer
 - Slice-based parallel H.264 decoding
 - Monkey's Audio demuxer and decoder
+- AMV audio decoder
 
 version 0.4.9-pre1:
 

doc/general.texi

@@ -249,6 +249,8 @@ following image formats are supported:
 @item AAC                    @tab X    @tab X
 @tab Supported through the external library libfaac/libfaad.
 @item Microsoft ADPCM        @tab X    @tab X
+@item AMV IMA ADPCM          @tab      @tab X
+@tab Used in AMV files
 @item MS IMA ADPCM           @tab X    @tab X
 @item QT IMA ADPCM           @tab      @tab X
 @item 4X IMA ADPCM           @tab      @tab X