rtpmap is case-insensitive, see comment from Luca in "[PATCH] rtsp.c:

keep-alive" thread.

Originally committed as revision 17862 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/rtsp.c

@@ -124,7 +124,7 @@ static int sdp_parse_rtpmap(AVCodecContext *codec, RTSPStream *rtsp_st, int payl
     if (payload_type >= RTP_PT_PRIVATE) {
         RTPDynamicProtocolHandler *handler= RTPFirstDynamicPayloadHandler;
         while(handler) {
-            if (!strcmp(buf, handler->enc_name) && (codec->codec_type == handler->codec_type)) {
+            if (!strcasecmp(buf, handler->enc_name) && (codec->codec_type == handler->codec_type)) {
                 codec->codec_id = handler->codec_id;
                 rtsp_st->dynamic_handler= handler;
                 if(handler->open) {