diff --git a/trunk/src/app/srs_app_http_api.cpp b/trunk/src/app/srs_app_http_api.cpp
index 424e3e4c7..52e25afb6 100644
--- a/trunk/src/app/srs_app_http_api.cpp
+++ b/trunk/src/app/srs_app_http_api.cpp
@@ -884,7 +884,7 @@ srs_error_t SrsGoApiRtcPlay::do_serve_http(ISrsHttpResponseWriter* w, ISrsHttpMe
     // TODO: FIXME: It seems remote_sdp doesn't represents the full SDP information.
     SrsSdp remote_sdp;
     if ((err = remote_sdp.parse(remote_sdp_str)) != srs_success) {
-        return srs_error_wrap(err, "parse sdp failed");
+        return srs_error_wrap(err, "parse sdp failed: %s", remote_sdp_str.c_str());
     }
 
     if ((err = check_remote_sdp(remote_sdp)) != srs_success) {
@@ -921,7 +921,7 @@ srs_error_t SrsGoApiRtcPlay::do_serve_http(ISrsHttpResponseWriter* w, ISrsHttpMe
     res->set("sdp", SrsJsonAny::str(local_sdp_str.c_str()));
     res->set("sessionid", SrsJsonAny::str(rtc_session->id().c_str()));
 
-    srs_trace("RTC sid=%s, answer=%dB", rtc_session->id().c_str(), local_sdp_str.length());
+    srs_trace("RTC sid=%s, offer=%dB, answer=%dB", rtc_session->id().c_str(), remote_sdp_str.length(), local_sdp_str.length());
 
     return err;
 }
@@ -1006,8 +1006,8 @@ srs_error_t SrsGoApiRtcPlay::exchange_sdp(const std::string& app, const std::str
             std::vector<SrsMediaPayloadType> payloads = remote_media_desc.find_media_with_encoding_name("H264");
             for (std::vector<SrsMediaPayloadType>::iterator iter = payloads.begin(); iter != payloads.end(); ++iter) {
                 H264SpecificParam h264_param;
-                if (parse_h264_fmtp(iter->format_specific_param_, h264_param) != 0) {
-                    continue;
+                if ((err = parse_h264_fmtp(iter->format_specific_param_, h264_param)) != srs_success) {
+                    srs_error_reset(err); continue;
                 }
 
                 if (h264_param.packetization_mode == 1 && h264_param.level_asymmerty_allow == 1) {
diff --git a/trunk/src/app/srs_app_rtc_conn.cpp b/trunk/src/app/srs_app_rtc_conn.cpp
index b09f7c4eb..07a927394 100644
--- a/trunk/src/app/srs_app_rtc_conn.cpp
+++ b/trunk/src/app/srs_app_rtc_conn.cpp
@@ -1124,7 +1124,7 @@ SrsRtcSession* SrsRtcServer::create_rtc_session(const SrsRequest& req, const Srs
     local_sdp.set_ice_pwd(local_pwd);
     local_sdp.set_fingerprint_algo("sha-256");
     local_sdp.set_fingerprint(SrsDtls::instance()->get_fingerprint());
-	std::vector<string> candidate_ips = get_candidate_ips();
+    std::vector<string> candidate_ips = get_candidate_ips();
     for (int i = 0; i < (int)candidate_ips.size(); ++i) {
         local_sdp.add_candidate(candidate_ips[i], _srs_config->get_rtc_server_listen(), "host");
     }
diff --git a/trunk/src/app/srs_app_sdp.cpp b/trunk/src/app/srs_app_sdp.cpp
index 047d417fa..6c128c180 100644
--- a/trunk/src/app/srs_app_sdp.cpp
+++ b/trunk/src/app/srs_app_sdp.cpp
@@ -416,7 +416,7 @@ srs_error_t SrsMediaDesc::parse_attr_rtpmap(const std::string& value)
 
     std::vector<std::string> vec = split_str(word, "/");
     if (vec.size() < 2) {
-        return srs_error_new(ERROR_RTC_SDP_DECODE, "invalid rtpmap line=%s", value);
+        return srs_error_new(ERROR_RTC_SDP_DECODE, "invalid rtpmap line=%s", value.c_str());
     }
 
     payload->encoding_name_ = vec[0];
@@ -525,7 +525,7 @@ srs_error_t SrsMediaDesc::parse_attr_ssrc(const std::string& value)
     } else if (ssrc_attr == "msid") {
         std::vector<std::string> vec = split_str(ssrc_value, " ");
         if (vec.empty()) {
-            return srs_error_new(ERROR_RTC_SDP_DECODE, "invalid ssrc line=%s", value);
+            return srs_error_new(ERROR_RTC_SDP_DECODE, "invalid ssrc line=%s", value.c_str());
         }
 
         ssrc_info.msid_ = vec[0];
@@ -611,7 +611,7 @@ srs_error_t SrsSdp::parse(const std::string& sdp_str)
     while (getline(is, line)) {
         srs_trace("%s", line.c_str());
         if (line.size() < 2 || line[1] != '=') {
-            return srs_error_new(ERROR_RTC_SDP_DECODE, "invalid sdp line=%s", line);
+            return srs_error_new(ERROR_RTC_SDP_DECODE, "invalid sdp line=%s", line.c_str());
         }
         if (! line.empty() && line[line.size()-1] == '\r') {
             line.erase(line.size()-1, 1);
diff --git a/trunk/src/app/srs_app_sdp.hpp b/trunk/src/app/srs_app_sdp.hpp
index 3aeaea32c..963eb3599 100644
--- a/trunk/src/app/srs_app_sdp.hpp
+++ b/trunk/src/app/srs_app_sdp.hpp
@@ -36,7 +36,7 @@ class SrsSessionInfo
 {
 public:
     SrsSessionInfo();
-    ~SrsSessionInfo();
+    virtual ~SrsSessionInfo();
 
     srs_error_t parse_attribute(const std::string& attribute, const std::string& value);
     srs_error_t encode(std::ostringstream& os);
@@ -84,7 +84,7 @@ class SrsMediaPayloadType
 {
 public:
     SrsMediaPayloadType(int payload_type);
-    ~SrsMediaPayloadType();
+    virtual ~SrsMediaPayloadType();
 
     srs_error_t encode(std::ostringstream& os);
 public:
@@ -109,7 +109,7 @@ class SrsMediaDesc
 {
 public:
     SrsMediaDesc(const std::string& type);
-    ~SrsMediaDesc();
+    virtual ~SrsMediaDesc();
 public:
     srs_error_t parse_line(const std::string& line);
     srs_error_t encode(std::ostringstream& os);
@@ -157,7 +157,7 @@ class SrsSdp
 {
 public:
     SrsSdp();
-    ~SrsSdp();
+    virtual ~SrsSdp();
 public:
     srs_error_t parse(const std::string& sdp_str);
     srs_error_t encode(std::ostringstream& os);