Add support for S8 PCM (codec 2)

Fix samples/au/vrooom.au

Originally committed as revision 11522 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/au.c

@@ -37,6 +37,7 @@
 /* The ffmpeg codecs we support, and the IDs they have in the file */
 static const AVCodecTag codec_au_tags[] = {
     { CODEC_ID_PCM_MULAW, 1 },
+    { CODEC_ID_PCM_S8, 2 },
     { CODEC_ID_PCM_S16BE, 3 },
     { CODEC_ID_PCM_ALAW, 27 },
     { 0, 0 },