Added basic stream fallback feature, allowing to redirect to a different stream name on stream source load errors

lib/stream.cpp

@@ -363,6 +363,7 @@ bool Util::startInput(std::string streamname, std::string filename, bool forkFir
   // check required parameters
   if (input.isMember("required")){
     jsonForEachConst(input["required"], prm){
+      if (!prm->isMember("option")){continue;}
       const std::string opt = (*prm)["option"].asStringRef();
       // check for overrides
       if (overrides.count(opt)){
@@ -379,6 +380,7 @@ bool Util::startInput(std::string streamname, std::string filename, bool forkFir
   // check optional parameters
   if (input.isMember("optional")){
     jsonForEachConst(input["optional"], prm){
+      if (!prm->isMember("option")){continue;}
       const std::string opt = (*prm)["option"].asStringRef();
       // check for overrides
       if (overrides.count(opt)){

src/input/input_buffer.cpp

@@ -82,6 +82,11 @@ namespace Mist {
     capa["optional"]["segmentsize"]["option"] = "--segment-size";
     capa["optional"]["segmentsize"]["type"] = "uint";
     capa["optional"]["segmentsize"]["default"] = 1900;
+
+    capa["optional"]["fallback_stream"]["name"] = "Fallback stream";
+    capa["optional"]["fallback_stream"]["help"] = "Alternative stream to load for playback when there is no active broadcast";
+    capa["optional"]["fallback_stream"]["type"] = "str";
+    capa["optional"]["fallback_stream"]["default"] = "";
     option.null();
     /*LTS-end*/
 

src/output/output.cpp

@@ -372,6 +372,19 @@ namespace Mist{
       }
     }else{
       if (!Util::startInput(streamName, "", true, isPushing())){
+        //If stream is configured, use fallback stream setting, if set.
+        JSON::Value strCnf = Util::getStreamConfig(streamName);
+        if (strCnf && strCnf["fallback_stream"].asStringRef().size()){
+          streamName = strCnf["fallback_stream"].asStringRef();
+          Util::Config::streamName = streamName;
+          INFO_MSG("Switching to configured fallback stream '%s'", streamName.c_str());
+          reconnect();
+          return;
+        }
+
+        //Not configured or no fallback stream? Use the default stream handler instead
+        //Note: Since fallback stream is handled recursively, the defaultStream handler
+        //may still be triggered for the fallback stream! This is intentional.
         JSON::Value defStrmJson = Util::getGlobalConfig("defaultStream");
         std::string defStrm = defStrmJson.asString();
         if(Triggers::shouldTrigger("DEFAULT_STREAM", streamName)){

src/output/output_hls.cpp

@@ -433,7 +433,8 @@ namespace Mist {
       H.Clean(); //clean for any possible next requests
       return;
     }else if (HTTP::URL(H.url).getExt().substr(0, 3) != "m3u") {
-      std::string tmpStr = H.getUrl().substr(5 + streamName.size());
+      size_t slashPos = H.getUrl().find('/', 5);
+      std::string tmpStr = H.getUrl().substr(slashPos);
       long long unsigned int from;
       if (sscanf(tmpStr.c_str(), "/%u_%u/%llu_%llu.ts", &vidTrack, &audTrack, &from, &until) != 4) {
         if (sscanf(tmpStr.c_str(), "/%u/%llu_%llu.ts", &vidTrack, &from, &until) != 3) {