fix bug of amf0 decode

 # the listen ports, split by space.
-listen              1935;
+listen              1937;
 # the default chunk size is 128, max is 65536,
 # some client does not support chunk size change,
 # however, most clients supports it and it can improve 

@@ -734,10 +734,12 @@ int srs_amf0_read_any(SrsStream* stream, SrsAmf0Any*& value)
 			return ret;
 		}
 		case RTMP_AMF0_Null: {
+			stream->skip(1);
 			value = new SrsAmf0Null();
 			return ret;
 		}
 		case RTMP_AMF0_Undefined: {
+			stream->skip(1);
 			value = new SrsAmf0Undefined();
 			return ret;
 		}

@@ -538,7 +538,7 @@ int SrsProtocol::on_recv_message(SrsCommonMessage* msg)
 	srs_assert(msg != NULL);
 		
 	// acknowledgement
-	if (skt->get_recv_bytes() - in_ack_size.acked_size > in_ack_size.ack_window_size) {
+	if (in_ack_size.ack_window_size > 0 && skt->get_recv_bytes() - in_ack_size.acked_size > in_ack_size.ack_window_size) {
 		if ((ret = response_acknowledgement_message()) != ERROR_SUCCESS) {
 			return ret;
 		}

@@ -359,7 +359,7 @@ int SrsSource::on_audio(SrsCommonMessage* audio)
 	if (codec->audio_is_sequence_header(msg->payload, msg->size)) {
 		srs_freep(cache_sh_audio);
 		cache_sh_audio = msg->copy();
-		srs_trace("update audio sequence header success.");
+		srs_trace("update audio sequence header success. size=%d", msg->header.payload_length);
 		return ret;
 	}
 	
@@ -404,7 +404,7 @@ int SrsSource::on_video(SrsCommonMessage* video)
 	if (codec->video_is_sequence_header(msg->payload, msg->size)) {
 		srs_freep(cache_sh_video);
 		cache_sh_video = msg->copy();
-		srs_trace("update video sequence header success.");
+		srs_trace("update video sequence header success. size=%d", msg->header.payload_length);
 		return ret;
 	}