ROUTE support using GPAC

[rbouqueau]

Work in progress. See #16. I put it here to get early feedback if any.

TODO:

• Isolate libflute use.
• Add ROUTE class.
• Provide demo material
• Rename variables containing the name 'flute' / cleanup.

[kuehnhammer]

Hi - just noticed your pull request, great to see that you already started with the integration!

I've just commited the code for seamless switching (see #19).
It includes the new abstraction for basic and seamless use cases, as well as the new cache management.

The location for the libflute calls has moved into ContentStream. I quite like your idea of using a lib-agnostic interface to handle file reception, I guess we could and should adapt the new classes accordingly as well.

[rbouqueau]

Hi Klaus, thanks for the feedback. I've just pushed a MVP.

To test the implementation:

1. Build GPAC as stated in the README.
2. Modify the code to create a ReceiverRoute instead of a ReceiverFlute, and adjust the listening address accordingly (e.g. 225.1.1.0:6000). Cf patch below.
3. Launch a fake ROUTE server: gpac -threads=-1 -i avgen:sr=48000:ch=2 @ ffenc:c=aac @1 ffenc:c=avc:fintra=2 @ @1 dasher:profile=live:dmode=dynamic @ -o route://225.1.1.0:6000/live.mpd (not low latency)

I have the following local patch:

diff --git a/src/Middleware.cpp b/src/Middleware.cpp
index 28bde09..6570cfb 100644
--- a/src/Middleware.cpp
+++ b/src/Middleware.cpp
@@ -45,7 +45,9 @@ void MBMS_RT::Middleware::tick_handler()
       if (!dest.empty() && is_service_announcement && _services.find(tmgi) == _services.end()) {
         // automatically start receiving the service announcement
         // 26.346 5.2.3.1.1 : the pre-defined TSI value shall be "0". 
+        dest = "225.1.1.0:6000"; //Harcoded
         _services[tmgi] = std::make_unique<MBMS_RT::Service>(_cfg, tmgi, dest, 0 /*TSI*/, _interface, _io_service);
       }
     }
diff --git a/src/Service.cpp b/src/Service.cpp
index 477363b..799e90b 100644
--- a/src/Service.cpp
+++ b/src/Service.cpp
@@ -18,6 +18,7 @@
 #include <regex>
 #include "Service.h"
 #include "ServiceFlute.h"
+#include "ServiceRoute.h"
 
 #include <boost/bind.hpp>
 #include "spdlog/spdlog.h"
@@ -40,7 +41,8 @@ MBMS_RT::Service::Service(const libconfig::Config& cfg, std::string tmgi, const
   _mcast_port = mcast.substr(delim + 1);
   spdlog::info("Starting FLUTE receiver on {}:{} for TSI {}", _mcast_addr, _mcast_port, _tsi); 
   _flute_thread = std::thread{[&](){
-    _flute_receiver = std::make_unique<ReceiverFlute>(_iface, _mcast_addr, atoi(_mcast_port.c_str()), _tsi, io_service);
+    _flute_receiver = std::make_unique<ReceiverRoute>(_iface, _mcast_addr, atoi(_mcast_port.c_str()), _tsi, io_service);
   }};
 }
 

Note that GPAC could have exposed the content directly using its HTTP embedded server. It allows to have low latency DASH(/HLS) ; otherwise if the HTTP server encounters the end of a served file it has no way to know if it is still being populated. But as per the discussion we had with the group I plugged on a lower level GPAC API.

[kuehnhammer]

As just discussed with Romain, I will test this and rebase it into the seamless-switching branch

[rbouqueau]

I've just had a look at the GPAC files we need to add at link time for a minimal link (see here):

• gpac/src/media_tools/route_dmx.o
• gpac/src/utils/list.o
• gpac/src/utils/alloc.o
• gpac/src/utils/error.o
• gpac/src/utils/os_divers.o
• gpac/src/utils/os_file.o
• gpac/src/utils/os_net.o
• gpac/src/utils/configfile.o
• gpac/src/utils/bitstream.o
• gpac/src/utils/xml_parser.o
• gpac/src/utils/os_thread.o
• gpac/src/utils/Remotery.o
• gpac/src/utils/gzio.o
• -ldl -lz -lGL
• gpac/src/utils/os_config_init.o
• gpac/src/utils/base_encoding.o
• gpac/src/utils/utf.o
• gpac/src/utils/module.o
• gpac/src/utils/url.o
• gpac/src/utils/os_module.o

gpac/src/media_tools/route_dmx.o gpac/src/utils/list.o gpac/src/utils/alloc.o gpac/src/utils/error.o gpac/src/utils/os_divers.o gpac/src/utils/os_file.o gpac/src/utils/os_net.o gpac/src/utils/configfile.o gpac/src/utils/bitstream.o gpac/src/utils/xml_parser.o gpac/src/utils/os_thread.o gpac/src/utils/Remotery.o gpac/src/utils/gzio.o -ldl -lz gpac/src/utils/os_config_init.o gpac/src/utils/base_encoding.o gpac/src/utils/utf.o gpac/src/utils/module.o -lGL gpac/src/utils/url.o gpac/src/utils/os_module.o