Basic metadata working librespot/server/client. Still missing client hooks.

The librespot metadata api kinda messy, no clear API. For now I addded
printing of artist in Librespot, should publish patch

client/Makefile

@@ -31,7 +31,8 @@ else
 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
+# Include the process.hpp for usage in meta tags callback
+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../server/streamreader
 LDFLAGS   = -logg -lFLAC
 OBJ       = snapClient.o stream.o clientConnection.o timeProvider.o player/player.o decoder/pcmDecoder.o decoder/oggDecoder.o decoder/flacDecoder.o controller.o ../message/pcmChunk.o ../common/sampleFormat.o
 

client/controller.cpp

@@ -138,9 +138,21 @@ void Controller::onMessageReceived(ClientConnection* connection, const msg::Base
 		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";
+		LOG(INFO) << "Stream tags: artist = <" << streamTags_->getArtist() << ">, album = <" << streamTags_->getAlbum() << ">, track = <" << streamTags_->getTrack() << ">\n";
+
+		// And we should trigger the meta tags script if given
+	        struct stat buffer;
+        	if(stat(meta_callback_.c_str(), &buffer) == 0)
+		{
+			LOG(INFO) << "About to execute meta tag callback script!\n";
+
+			// Check if its there, set environment and execute it
+			// Probably can use the process thing from streamreader
+		}
+		else
+		{
+			LOG(INFO) << "Meta tag callback script not found!\n";
+		}
         }
 
 	if (baseMessage.type != message_type::kTime)
@@ -163,10 +175,11 @@ bool Controller::sendTimeSyncMessage(long after)
 }
 
 
-void Controller::start(const PcmDevice& pcmDevice, const std::string& host, size_t port, int latency)
+void Controller::start(const PcmDevice& pcmDevice, const std::string& host, size_t port, int latency, const std::string& meta_callback)
 {
 	pcmDevice_ = pcmDevice;
 	latency_ = latency;
+	meta_callback_ = meta_callback;
 	clientConnection_.reset(new ClientConnection(this, host, port));
 	controllerThread_ = thread(&Controller::worker, this);
 }

client/controller.h

@@ -48,7 +48,7 @@ class Controller : public MessageReceiver
 {
 public:
 	Controller(const std::string& clientId, size_t instance);
-	void start(const PcmDevice& pcmDevice, const std::string& host, size_t port, int latency);
+	void start(const PcmDevice& pcmDevice, const std::string& host, size_t port, int latency, const std::string& meta_callback);
 	void stop();
 
 	/// Implementation of MessageReceiver.
@@ -63,6 +63,7 @@ private:
 	void worker();
 	bool sendTimeSyncMessage(long after = 1000);
 	std::string hostId_;
+	std::string meta_callback_;
 	size_t instance_;
 	std::atomic<bool> active_;
 	std::thread controllerThread_;

client/snapClient.cpp

@@ -73,6 +73,7 @@ int main (int argc, char **argv)
 	int exitcode = EXIT_SUCCESS;
 	try
 	{
+		string meta_callback("");
 		string soundcard("default");
 		string host("");
 		size_t port(1704);
@@ -87,6 +88,7 @@ int main (int argc, char **argv)
 		auto listSwitch =     op.add<Switch>("l", "list", "list pcm devices");
 		/*auto soundcardValue =*/ op.add<Value<string>>("s", "soundcard", "index or name of the soundcard", "default", &soundcard);
 #endif
+		/*auto metaValue =*/  op.add<Value<string>>("m", "meta", "script to call on meta tags", "", &meta_callback);
 		/*auto hostValue =*/  op.add<Value<string>>("h", "host", "server hostname or ip address", "", &host);
 		/*auto portValue =*/  op.add<Value<size_t>>("p", "port", "server port", 1704, &port);
 #ifdef HAS_DAEMON
@@ -230,7 +232,7 @@ int main (int argc, char **argv)
 		if (!g_terminated)
 		{
 			LOG(INFO) << "Latency: " << latency << "\n";
-			controller->start(pcmDevice, host, port, latency);
+			controller->start(pcmDevice, host, port, latency, meta_callback);
 			while(!g_terminated)
 				chronos::sleep(100);
 			controller->stop();

common/metatags.h

@@ -1,35 +0,0 @@
-/***
-    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/streamTags.h

@@ -21,6 +21,19 @@
 
 #include "jsonMessage.h"
 
+/*
+ * Due to the PCM pipe implementation of snapcast input we cannot know track start/end
+ * it's all a long stream (although we detect idle situations)
+ * 
+ * So, we cannot push metadata on start of track as we don't know when that is.
+ * 
+ * I.E. we push metadata as we get an update, as we don't know when an update
+ * is complete (different meta supported in different stream interfaces)
+ * it is the streamreaders responsibility to update metadata and 
+ * trigger a client notification.
+ *
+ * I.E. we need to suppply the client notification mechanism.
+ */
 
 namespace msg
 {
@@ -33,12 +46,23 @@ public:
 		msg["meta_artist"]    = "";
 		msg["meta_album"]     = "";
 		msg["meta_track"]     = "";
+		msg["meta_albumart"]  = "";
 	}
 
 	virtual ~StreamTags()
 	{
 	}
 
+	json toJson() const
+	{
+		json j = {
+			{"artist", getArtist()},
+			{"album", getAlbum()},
+			{"track", getTrack()},
+		};
+		return j;
+	}
+
 	std::string getArtist() const
 	{
 		return msg["meta_artist"];
@@ -54,6 +78,11 @@ public:
 		return msg["meta_track"];
 	}
 
+	std::string getAlbumArt() const
+	{
+		return msg["meta_albumart"];
+	}
+
 	void setArtist(std::string artist)
 	{
 		msg["meta_artist"] = artist;
@@ -68,6 +97,12 @@ public:
 	{
 		msg["meta_track"] = track;
 	}
+
+	// Ascii encoded image XXX: more details
+	void setAlbumArt(std::string art)
+	{
+		msg["meta_albumart"] = art;
+	}
 };
 
 }

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/metatags.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/sampleFormat.o ../message/pcmChunk.o ../externals/jsonrpcpp/lib/jsonrp.o
 
 
 ifneq (,$(TARGET))

server/streamServer.cpp

@@ -39,6 +39,23 @@ StreamServer::~StreamServer()
 }
 
 
+void StreamServer::onMetaChanged(const PcmStream* pcmStream) 
+{
+	/// Notification: {"jsonrpc":"2.0","method":"Stream.OnMetadata","params":{"id":"stream 1", "meta": {"album": "some album", "artist": "some artist", "track": "some track"...}}
+
+	const auto meta = pcmStream->getMeta();
+	for (auto s : sessions_)
+	{
+		if (s->pcmStream().get() == pcmStream)
+			s->sendAsync(meta);
+	}
+
+	LOG(INFO) << "onMetaChanged (" << pcmStream->getName() << ")\n";
+	json notification = jsonrpcpp::Notification("Stream.OnMetadata", jsonrpcpp::Parameter("id", pcmStream->getId(), "meta", meta->toJson())).to_json();
+	controlServer_->send(notification.dump(), NULL);
+	cout << "Notification: " << notification.dump() << "\n";
+}
+
 void StreamServer::onStateChanged(const PcmStream* pcmStream, const ReaderState& state)
 {
 	/// Notification: {"jsonrpc":"2.0","method":"Stream.OnUpdate","params":{"id":"stream 1","stream":{"id":"stream 1","status":"idle","uri":{"fragment":"","host":"","path":"/tmp/snapfifo","query":{"buffer_ms":"20","codec":"flac","name":"stream 1","sampleformat":"48000:16:2"},"raw":"pipe:///tmp/snapfifo?name=stream 1","scheme":"pipe"}}}}
@@ -251,6 +268,7 @@ void StreamServer::ProcessRequest(const jsonrpcpp::request_ptr request, jsonrpcp
 					session_ptr session = getStreamSession(client->id);
 					if (session && (session->pcmStream() != stream))
 					{
+						session->sendAsync(stream->getMeta());
 						session->sendAsync(stream->getHeader());
 						session->setPcmStream(stream);
 					}
@@ -303,6 +321,7 @@ void StreamServer::ProcessRequest(const jsonrpcpp::request_ptr request, jsonrpcp
 					session_ptr session = getStreamSession(client->id);
 					if (session && stream && (session->pcmStream() != stream))
 					{
+						session->sendAsync(stream->getMeta());
 						session->sendAsync(stream->getHeader());
 						session->setPcmStream(stream);
 					}
@@ -517,14 +536,7 @@ 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/streamServer.h

@@ -92,6 +92,7 @@ public:
 	virtual void onMessageReceived(ControlSession* connection, const std::string& message);
 
 	/// Implementation of PcmListener
+	virtual void onMetaChanged(const PcmStream* pcmStream);
 	virtual void onStateChanged(const PcmStream* pcmStream, const ReaderState& state);
 	virtual void onChunkRead(const PcmStream* pcmStream, msg::PcmChunk* chunk, double duration);
 	virtual void onResync(const PcmStream* pcmStream, double ms);

server/streamreader/pcmStream.cpp

@@ -171,7 +171,8 @@ json PcmStream::toJson() const
 	json j = {
 		{"uri", uri_.toJson()},
 		{"id", getId()},
-		{"status", state}
+		{"status", state},
+                {"meta", meta_->toJson()}
 	};
 	return j;
 }

server/streamreader/pcmStream.h

@@ -51,6 +51,7 @@ enum ReaderState
 class PcmListener
 {
 public:
+	virtual void onMetaChanged(const PcmStream* pcmStream) = 0;
 	virtual void onStateChanged(const PcmStream* pcmStream, const ReaderState& state) = 0;
 	virtual void onChunkRead(const PcmStream* pcmStream, msg::PcmChunk* chunk, double duration) = 0;
 	virtual void onResync(const PcmStream* pcmStream, double ms) = 0;
@@ -86,7 +87,7 @@ public:
 	virtual json toJson() const;
 
 	//const msg::StreamTags *getMeta()
-        std::shared_ptr<msg::StreamTags> getMeta()
+        std::shared_ptr<msg::StreamTags> getMeta() const
 	{
 		return meta_;
 	}

server/streamreader/spotifyStream.cpp

@@ -115,6 +115,7 @@ void SpotifyStream::onStderrMsg(const char* buffer, size_t n)
 	// 2016-11-03 09-00-18 [out] INFO:librespot::session: Authenticated !
 	watchdog_->trigger();
 	string logmsg = utils::string::trim_copy(string(buffer, n));
+
 	if ((logmsg.find("allocated stream") == string::npos) &&
 		(logmsg.find("Got channel") == string::npos) &&
 		(logmsg.find('\0') == string::npos) &&
@@ -123,16 +124,24 @@ void SpotifyStream::onStderrMsg(const char* buffer, size_t n)
 		LOG(INFO) << "(" << getName() << ") " << logmsg << "\n";
 	}
 
-	// Check for metadata
-	if (logmsg.find("Loading track") != string::npos)
+	// Track tags "Julia Michaels" "Issues - Acoustic"
+	if (logmsg.find("Track tags") != string::npos)
 	{
-		regex re("Loading track \"(.*)\"");
+		// Traditional Libreelec meta interface, only track name
+		regex re("Track tags \"(.*)\" \"(.*)\"");
 		smatch m;
 
 		if (regex_search(logmsg, m, re))
 		{
-			LOG(INFO) << "Loading track (" << m[1] << ")\n";
-			getMeta()->setTrack(m[1]);
+			// Create a new meta struct?
+			LOG(INFO) << "Loading track <" << m[1] << "> <" << m[2] << ">\n";
+			getMeta()->setArtist(m[1]);
+			getMeta()->setAlbum("");
+			getMeta()->setTrack(m[2]);
+
+			// Trigger a stream update
+			if (pcmListener_)
+				pcmListener_->onMetaChanged(this);
 		}
 	}
 }