Add meta stream source

server/streamreader/meta_stream.hpp

@@ -0,0 +1,64 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2020  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 META_STREAM_HPP
+#define META_STREAM_HPP
+
+#include "posix_stream.hpp"
+#include "resampler.hpp"
+#include <memory>
+
+namespace streamreader
+{
+
+
+/// Reads and decodes PCM data
+/**
+ * Reads PCM and passes the data to an encoder.
+ * Implements EncoderListener to get the encoded data.
+ * Data is passed to the PcmListener
+ */
+class MetaStream : public PcmStream, public PcmListener
+{
+public:
+    /// ctor. Encoded PCM data is passed to the PcmListener
+    MetaStream(PcmListener* pcmListener, std::vector<std::shared_ptr<PcmStream>> streams, boost::asio::io_context& ioc, const StreamUri& uri);
+    virtual ~MetaStream();
+
+    virtual void start();
+    virtual void stop();
+
+protected:
+    /// Implementation of PcmListener
+    void onMetaChanged(const PcmStream* pcmStream) override;
+    void onStateChanged(const PcmStream* pcmStream, ReaderState state) override;
+    void onChunkRead(const PcmStream* pcmStream, const msg::PcmChunk& chunk) override;
+    void onChunkEncoded(const PcmStream* pcmStream, std::shared_ptr<msg::PcmChunk> chunk, double duration) override;
+    void onResync(const PcmStream* pcmStream, double ms) override;
+
+protected:
+    std::vector<std::shared_ptr<PcmStream>> streams_;
+    std::shared_ptr<PcmStream> active_stream_;
+    std::mutex mutex_;
+    std::unique_ptr<Resampler> resampler_;
+    bool first_read_;
+};
+
+} // namespace streamreader
+
+#endif