diff --git a/libavformat/mmst.c b/libavformat/mmst.c
index a97c2e04a2..533cbe7698 100644
--- a/libavformat/mmst.c
+++ b/libavformat/mmst.c
@@ -141,7 +141,7 @@ static int send_command_packet(MMSTContext *mmst)
     // write it out.
     write_result= ffurl_write(mms->mms_hd, mms->out_buffer, exact_length);
     if(write_result != exact_length) {
-        av_log(NULL, AV_LOG_ERROR,
+        av_log(mms->mms_hd, AV_LOG_ERROR,
                "Failed to write data of length %d: %d (%s)\n",
                exact_length, write_result,
                write_result < 0 ? strerror(AVUNERROR(write_result)) :
@@ -215,11 +215,11 @@ static int send_media_file_request(MMSTContext *mmst)
 static void handle_packet_stream_changing_type(MMSTContext *mmst)
 {
     MMSContext *mms = &mmst->mms;
-    av_log(NULL, AV_LOG_TRACE, "Stream changing!\n");
+    av_log(mms->mms_hd, AV_LOG_TRACE, "Stream changing!\n");
 
     // 40 is the packet header size, 7 is the prefix size.
     mmst->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7);
-    av_log(NULL, AV_LOG_TRACE, "Changed header prefix to 0x%x", mmst->header_packet_id);
+    av_log(mms->mms_hd, AV_LOG_TRACE, "Changed header prefix to 0x%x", mmst->header_packet_id);
 }
 
 static int send_keepalive_packet(MMSTContext *mmst)
@@ -251,12 +251,12 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
         read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer, 8);
         if (read_result != 8) {
             if(read_result < 0) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Error reading packet header: %d (%s)\n",
                        read_result, strerror(AVUNERROR(read_result)));
                 packet_type = SC_PKT_CANCEL;
             } else {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "The server closed the connection\n");
                 packet_type = SC_PKT_NO_DATA;
             }
@@ -270,7 +270,7 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
             mmst->incoming_flags= mms->in_buffer[3];
             read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer+8, 4);
             if(read_result != 4) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Reading command packet length failed: %d (%s)\n",
                        read_result,
                        read_result < 0 ? strerror(AVUNERROR(read_result)) :
@@ -279,11 +279,11 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
             }
 
             length_remaining= AV_RL32(mms->in_buffer+8) + 4;
-            av_log(NULL, AV_LOG_TRACE, "Length remaining is %d\n", length_remaining);
+            av_log(mms->mms_hd, AV_LOG_TRACE, "Length remaining is %d\n", length_remaining);
             // read the rest of the packet.
             if (length_remaining < 0
                 || length_remaining > sizeof(mms->in_buffer) - 12) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Incoming packet length %d exceeds bufsize %"SIZE_SPECIFIER"\n",
                        length_remaining, sizeof(mms->in_buffer) - 12);
                 return AVERROR_INVALIDDATA;
@@ -291,7 +291,7 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
             read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer + 12,
                                             length_remaining) ;
             if (read_result != length_remaining) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Reading pkt data (length=%d) failed: %d (%s)\n",
                        length_remaining, read_result,
                        read_result < 0 ? strerror(AVUNERROR(read_result)) :
@@ -300,7 +300,7 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
             }
             packet_type= AV_RL16(mms->in_buffer+36);
             if (read_result >= 44 && (hr = AV_RL32(mms->in_buffer + 40))) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Server sent a message with packet type 0x%x and error status code 0x%08x\n", packet_type, hr);
                 return AVERROR(EINVAL);
             }
@@ -319,7 +319,7 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
 
             if (length_remaining < 0
                 || length_remaining > sizeof(mms->in_buffer) - 8) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Data length %d is invalid or too large (max=%"SIZE_SPECIFIER")\n",
                        length_remaining, sizeof(mms->in_buffer));
                 return AVERROR_INVALIDDATA;
@@ -328,7 +328,7 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
             mms->read_in_ptr         = mms->in_buffer;
             read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer, length_remaining);
             if(read_result != length_remaining) {
-                av_log(NULL, AV_LOG_ERROR,
+                av_log(mms->mms_hd, AV_LOG_ERROR,
                        "Failed to read packet data of size %d: %d (%s)\n",
                        length_remaining, read_result,
                        read_result < 0 ? strerror(AVUNERROR(read_result)) :
@@ -358,7 +358,7 @@ static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
             } else if(packet_id_type == mmst->packet_id) {
                 packet_type = SC_PKT_ASF_MEDIA;
             } else {
-                av_log(NULL, AV_LOG_TRACE, "packet id type %d is old.", packet_id_type);
+                av_log(mms->mms_hd, AV_LOG_TRACE, "packet id type %d is old.", packet_id_type);
                 continue;
             }
         }
@@ -555,14 +555,14 @@ static int mms_open(URLContext *h, const char *uri, int flags)
     if (err)
         goto fail;
     if((mmst->incoming_flags != 0X08) && (mmst->incoming_flags != 0X0C)) {
-        av_log(NULL, AV_LOG_ERROR,
+        av_log(h, AV_LOG_ERROR,
                "The server does not support MMST (try MMSH or RTSP)\n");
         err = AVERROR(EINVAL);
         goto fail;
     }
     err = ff_mms_asf_header_parser(mms);
     if (err) {
-        av_log(NULL, AV_LOG_TRACE, "asf header parsed failed!\n");
+        av_log(h, AV_LOG_TRACE, "asf header parsed failed!\n");
         goto fail;
     }
     mms->header_parsed = 1;
@@ -579,11 +579,11 @@ static int mms_open(URLContext *h, const char *uri, int flags)
     if (err) {
         goto fail;
     }
-    av_log(NULL, AV_LOG_TRACE, "Leaving open (success)\n");
+    av_log(h, AV_LOG_TRACE, "Leaving open (success)\n");
     return 0;
 fail:
     mms_close(h);
-    av_log(NULL, AV_LOG_TRACE, "Leaving open (failure: %d)\n", err);
+    av_log(mms->mms_hd, AV_LOG_TRACE, "Leaving open (failure: %d)\n", err);
     return err;
 }
 
@@ -608,7 +608,7 @@ static int mms_read(URLContext *h, uint8_t *buf, int size)
             int err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_MEDIA);
             if (err == 0) {
                 if(mms->remaining_in_len>mms->asf_packet_len) {
-                    av_log(NULL, AV_LOG_ERROR,
+                    av_log(h, AV_LOG_ERROR,
                            "Incoming pktlen %d is larger than ASF pktsize %d\n",
                            mms->remaining_in_len, mms->asf_packet_len);
                     result= AVERROR(EIO);
@@ -616,12 +616,12 @@ static int mms_read(URLContext *h, uint8_t *buf, int size)
                     // copy the data to the packet buffer.
                     result = ff_mms_read_data(mms, buf, size);
                     if (result == 0) {
-                        av_log(NULL, AV_LOG_TRACE, "Read ASF media packet size is zero!\n");
+                        av_log(h, AV_LOG_TRACE, "Read ASF media packet size is zero!\n");
                         break;
                     }
                 }
             } else {
-                av_log(NULL, AV_LOG_TRACE, "read packet error!\n");
+                av_log(h, AV_LOG_TRACE, "read packet error!\n");
                 break;
             }
         }