fix the aggregate bug, adjust to starttime of msg. 2.0.91

@@ -1481,6 +1481,9 @@ int SrsSource::on_aggregate(SrsCommonMessage* msg)
         return ret;
     }
     
+    // the aggregate message always use abs time.
+    int delta = -1;
+    
     while (!stream->empty()) {
         if (!stream->require(1)) {
             ret = ERROR_RTMP_AGGREGATE;
@@ -1519,6 +1522,12 @@ int SrsSource::on_aggregate(SrsCommonMessage* msg)
         timestamp |= time_h<<24;
         timestamp &= 0x7FFFFFFF;
         
+        // adjust abs timestamp in aggregate msg.
+        if (delta < 0) {
+            delta = (int)msg->header.timestamp - (int)timestamp;
+        }
+        timestamp += delta;
+        
         if (!stream->require(3)) {
             ret = ERROR_RTMP_AGGREGATE;
             srs_error("invalid aggregate message stream_id. ret=%d", ret);

@@ -31,7 +31,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // current release version
 #define VERSION_MAJOR       2
 #define VERSION_MINOR       0
-#define VERSION_REVISION    90
+#define VERSION_REVISION    91
 // server info.
 #define RTMP_SIG_SRS_KEY "SRS"
 #define RTMP_SIG_SRS_ROLE "origin/edge server"

@@ -823,7 +823,9 @@ int __srs_rtmp_on_aggregate(Context* context, SrsCommonMessage* msg)
         return ret;
     }
     
+    // the aggregate message always use abs time.
     int delta = -1;
+    
     while (!stream->empty()) {
         if (!stream->require(1)) {
             ret = ERROR_RTMP_AGGREGATE;
@@ -862,7 +864,7 @@ int __srs_rtmp_on_aggregate(Context* context, SrsCommonMessage* msg)
         timestamp |= time_h<<24;
         timestamp &= 0x7FFFFFFF;
         
-        // adjust timestamp.
+        // adjust abs timestamp in aggregate msg.
         if (delta < 0) {
             delta = (int)msg->header.timestamp - (int)timestamp;
         }