merge from srs2.

@@ -928,12 +928,12 @@ vhost with-hls.srs.com {
         # default: 60
         hls_window      60;
         # the error strategy. canbe:
-        #       ignore, when error ignore and disable hls.
-        #       disconnect, when error disconnect the publish connection.
-        #       continue, when error ignore and continue output hls.
+        #       ignore, disable the hls.
+        #       disconnect, require encoder republish.
+        #       continue, ignore failed try to continue output hls.
         # @see https://github.com/ossrs/srs/issues/264
-        # default: ignore
-        hls_on_error    ignore;
+        # default: continue
+        hls_on_error    continue;
         # the hls storage: disk, ram or both.
         #       disk, to write hls m3u8/ts to disk.
         #       ram, serve m3u8/ts in memory, which use embeded http server to delivery.

@@ -6002,7 +6002,8 @@ double SrsConfig::get_hls_window(string vhost)
 
 string SrsConfig::get_hls_on_error(string vhost)
 {
-    static string DEFAULT = "ignore";
+    // try to ignore the error.
+    static string DEFAULT = "continue";
     
     SrsConfDirective* conf = get_hls(vhost);
     if (!conf) {

@@ -1770,6 +1770,23 @@ int SrsSource::on_video(SrsCommonMessage* shared_video)
     return ret;
 }
 
+bool srs_hls_can_continue(int ret, SrsSharedPtrMessage* sh, SrsSharedPtrMessage* video)
+{
+    // only continue for decode error.
+    if (ret != ERROR_HLS_DECODE_ERROR) {
+        return false;
+    }
+    
+    // when video size equals to sequence header,
+    // the video actually maybe a sequence header,
+    // continue to make ffmpeg happy.
+    if (sh && sh->size == video->size) {
+        return true;
+    }
+    
+    return false;
+}
+
 int SrsSource::on_video_imp(SrsSharedPtrMessage* msg)
 {
     int ret = ERROR_SUCCESS;
@@ -1834,7 +1851,7 @@ int SrsSource::on_video_imp(SrsSharedPtrMessage* msg)
             ret = ERROR_SUCCESS;
         } else if (srs_config_hls_is_on_error_continue(hls_error_strategy)) {
             // compare the sequence header with video, continue when it's actually an sequence header.
-            if (ret == ERROR_HLS_DECODE_ERROR && cache_sh_video && cache_sh_video->size == msg->size) {
+            if (srs_hls_can_continue(ret, cache_sh_video, msg)) {
                 srs_warn("the video is actually a sequence header, ignore this packet.");
                 ret = ERROR_SUCCESS;
             } else {