Added basics for maintaining metadata by stream on server and pushing to clients.

Modified Spotify stream handler to get the track name from Libreelec's stderr.
Note, to support artist/album (or album art) we need to modify Libreelec
to print these.

client/controller.cpp

@@ -133,6 +133,15 @@ void Controller::onMessageReceived(ClientConnection* connection, const msg::Base
 		player_->setMute(serverSettings_->isMuted());
 		player_->start();
 	}
+	else if (baseMessage.type == message_type::kStreamTags)
+        {
+		streamTags_.reset(new msg::StreamTags());
+		streamTags_->deserialize(baseMessage, buffer);
+
+		LOG(INFO) << "Tag received: artist = " << streamTags_->getArtist() << "\n";
+		LOG(INFO) << "Tag received: album = " << streamTags_->getAlbum() << "\n";
+		LOG(INFO) << "Tag received: track = " << streamTags_->getTrack() << "\n";
+        }
 
 	if (baseMessage.type != message_type::kTime)
 		if (sendTimeSyncMessage(1000))

client/controller.h

@@ -24,6 +24,7 @@
 #include "decoder/decoder.h"
 #include "message/message.h"
 #include "message/serverSettings.h"
+#include "message/streamTags.h"
 #include "player/pcmDevice.h"
 #ifdef HAS_ALSA
 #include "player/alsaPlayer.h"
@@ -73,6 +74,7 @@ private:
 	std::unique_ptr<Decoder> decoder_;
 	std::unique_ptr<Player> player_;
 	std::shared_ptr<msg::ServerSettings> serverSettings_;
+	std::shared_ptr<msg::StreamTags> streamTags_;
 	std::shared_ptr<msg::CodecHeader> headerChunk_;
 	std::mutex receiveMutex_;
 

common/metatags.h

@@ -0,0 +1,35 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2017  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifndef METATAGS_DATA_H
+#define METATAGS_DATA_H
+
+#include "message/streamTags.h"
+
+class MetaTags 
+{
+public:
+	MetaTags();
+	virtual ~MetaTags();
+
+private:
+};
+
+
+
+#endif

message/message.h

@@ -57,9 +57,10 @@ enum message_type
 	kServerSettings = 3,
 	kTime = 4,
 	kHello = 5,
+	kStreamTags = 6,
 
 	kFirst = kBase,
-	kLast = kHello
+	kLast = kStreamTags
 };
 
 

message/streamTags.h

@@ -0,0 +1,78 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2017  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifndef STREAMTAGS_H
+#define STREAMTAGS_H
+
+#include "jsonMessage.h"
+
+
+namespace msg
+{
+
+class StreamTags : public JsonMessage
+{
+public:
+	StreamTags() : JsonMessage(message_type::kStreamTags)
+	{
+		msg["meta_artist"] = "";
+		msg["meta_album"]  = "";
+		msg["meta_track"]  = "";
+	}
+
+	virtual ~StreamTags()
+	{
+	}
+
+	std::string getArtist() const
+	{
+		return msg["meta_artist"];
+	}
+
+	std::string getAlbum() const
+	{
+		return msg["meta_album"];
+	}
+
+	std::string getTrack() const
+	{
+		return msg["meta_track"];
+	}
+
+	void setArtist(std::string artist)
+	{
+		msg["meta_artist"] = artist;
+	}
+
+	void setAlbum(std::string album)
+	{
+		msg["meta_album"] = album;
+	}
+
+	void setTrack(std::string track)
+	{
+		msg["meta_track"] = track;
+	}
+};
+
+}
+
+
+#endif
+
+

server/Makefile

@@ -33,7 +33,7 @@ endif
 
 CXXFLAGS += $(ADD_CFLAGS) -std=c++0x -Wall -Wno-unused-function -O3 -DASIO_STANDALONE -DVERSION=\"$(VERSION)\" -I. -I.. -isystem ../externals/asio/asio/include -I../externals/popl/include -I../externals/aixlog/include -I../externals/jsonrpcpp/lib -I../externals
 LDFLAGS   = -lvorbis -lvorbisenc -logg -lFLAC
-OBJ       = snapServer.o config.o controlServer.o controlSession.o streamServer.o streamSession.o streamreader/streamUri.o streamreader/streamManager.o streamreader/pcmStream.o streamreader/pipeStream.o streamreader/fileStream.o streamreader/processStream.o streamreader/airplayStream.o streamreader/spotifyStream.o streamreader/watchdog.o encoder/encoderFactory.o encoder/flacEncoder.o encoder/pcmEncoder.o encoder/oggEncoder.o ../common/sampleFormat.o ../message/pcmChunk.o ../externals/jsonrpcpp/lib/jsonrp.o
+OBJ       = snapServer.o config.o controlServer.o controlSession.o streamServer.o streamSession.o streamreader/streamUri.o streamreader/streamManager.o streamreader/pcmStream.o streamreader/pipeStream.o streamreader/fileStream.o streamreader/processStream.o streamreader/airplayStream.o streamreader/spotifyStream.o streamreader/watchdog.o encoder/encoderFactory.o encoder/flacEncoder.o encoder/pcmEncoder.o encoder/oggEncoder.o ../common/metatags.o ../common/sampleFormat.o ../message/pcmChunk.o ../externals/jsonrpcpp/lib/jsonrp.o
 
 
 ifneq (,$(TARGET))

server/streamServer.cpp

@@ -19,6 +19,7 @@
 #include "streamServer.h"
 #include "message/time.h"
 #include "message/hello.h"
+#include "message/streamTags.h"
 #include "aixlog.hpp"
 #include "config.h"
 #include <iostream>
@@ -516,6 +517,14 @@ void StreamServer::onMessageReceived(StreamSession* connection, const msg::BaseM
 
 		Config::instance().save();
 
+		// Send the group stream tags
+                LOG(INFO) << "request kStreamTags\n";
+		//auto metaTags = make_shared<msg::StreamTags>();
+		//metaTags->setArtist(stream->getMeta()->getArtist());
+		//connection->sendAsync(metaTags);
+		connection->sendAsync(stream->getMeta());
+                LOG(INFO) << "kStreamTags sent\n";
+
 		connection->setPcmStream(stream);
 		auto headerChunk = stream->getHeader();
 		connection->sendAsync(headerChunk);

server/streamreader/pcmStream.cpp

@@ -55,6 +55,9 @@ PcmStream::PcmStream(PcmListener* pcmListener, const StreamUri& uri) :
 		dryoutMs_ = cpt::stoul(uri_.query["dryout_ms"]);
 	else
 		dryoutMs_ = 2000;
+
+	// meta_.reset(new msg::StreamTags);
+	meta_ = make_shared<msg::StreamTags>();
 }
 
 

server/streamreader/pcmStream.h

@@ -30,6 +30,7 @@
 #include "externals/json.hpp"
 #include "common/sampleFormat.h"
 #include "message/codecHeader.h"
+#include "message/streamTags.h"
 
 
 class PcmStream;
@@ -84,6 +85,12 @@ public:
 	virtual ReaderState getState() const;
 	virtual json toJson() const;
 
+	//const msg::StreamTags *getMeta()
+        std::shared_ptr<msg::StreamTags> getMeta()
+	{
+		return meta_;
+	}
+
 
 protected:
 	std::condition_variable cv_;
@@ -104,6 +111,9 @@ protected:
 	std::unique_ptr<Encoder> encoder_;
 	std::string name_;
 	ReaderState state_;
+
+	// Stream metadata
+        std::shared_ptr<msg::StreamTags> meta_;
 };
 
 

server/streamreader/spotifyStream.cpp

@@ -16,6 +16,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <regex>
 #include "spotifyStream.h"
 #include "common/snapException.h"
 #include "common/utils/string_utils.h"
@@ -92,6 +93,9 @@ void SpotifyStream::initExeAndPath(const std::string& filename)
 
 void SpotifyStream::onStderrMsg(const char* buffer, size_t n)
 {
+	// Watch stderr for 'Loading track' messages and set the stream metadata
+	// For more than track name check: https://github.com/plietar/librespot/issues/154
+
 	/// Watch will kill librespot if there was no message received for 130min
 	// 2016-11-02 22-05-15 [out] TRACE:librespot::stream: allocated stream 3580
 	// 2016-11-02 22-05-15 [Debug] DEBUG:librespot::audio_file2: Got channel 3580
@@ -118,6 +122,19 @@ void SpotifyStream::onStderrMsg(const char* buffer, size_t n)
 	{
 		LOG(INFO) << "(" << getName() << ") " << logmsg << "\n";
 	}
+
+	// Check for metadata
+	if (logmsg.find("Loading track") != string::npos)
+	{
+		regex re("Loading track \"(.*)\"");
+		smatch m;
+
+		if (regex_search(logmsg, m, re))
+		{
+			LOG(INFO) << "Loading track (" << m[1] << ")\n";
+			getMeta()->setTrack(m[1]);
+		}
+	}
 }