diff --git a/src/stream.h b/src/stream.h
new file mode 100644
--- /dev/null
+++ b/src/stream.h
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+/*
+  Copyright © 2018 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot 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.
+
+  serialplot 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 serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef STREAM_H
+#define STREAM_H
+
+#include <QObject>
+#include <QModelIndex>
+#include <QVector>
+#include <QSettings>
+
+#include "sink.h"
+#include "source.h"
+#include "channelinfomodel.h"
+#include "streamchannel.h"
+#include "framebuffer.h"
+
+/**
+ * Main waveform storage class. It consists of channels. Channels are
+ * synchronized with each other.
+ *
+ * Implements `Sink` class for data entry. It's expected to be
+ * connected to a `Device` source.
+ */
+class Stream : public QObject, public Sink
+{
+    Q_OBJECT
+
+public:
+    /**
+     * @param nc number of channels
+     * @param x has X data input
+     * @param ns number of samples
+     */
+    Stream(unsigned nc = 0, bool x = false, unsigned ns = 0);
+    ~Stream();
+
+    // implementations for `Source`
+    virtual bool hasX() const;
+    virtual unsigned numChannels() const;
+
+    unsigned numSamples() const;
+    const StreamChannel* channel(unsigned index) const;
+    StreamChannel* channel(unsigned index);
+    const ChannelInfoModel* infoModel() const;
+    ChannelInfoModel* infoModel();
+
+    /// Saves channel information
+    void saveSettings(QSettings* settings) const;
+    /// Load channel information
+    void loadSettings(QSettings* settings);
+
+protected:
+    // implementations for `Sink`
+    virtual void setNumChannels(unsigned nc, bool x);
+    virtual void feedIn(const SamplePack& pack);
+
+signals:
+    void numChannelsChanged(unsigned value);
+    void numSamplesChanged(unsigned value);
+    void channelAdded(const StreamChannel* chan);
+    void channelNameChanged(unsigned channel, QString name); // TODO: does it stay?
+    void dataAdded(); ///< emitted when data added to channel man.
+
+public slots:
+    // TODO: these won't be public
+    // void setNumChannels(unsigned number);
+    void setNumSamples(unsigned value);
+
+    /// When paused data feed is ignored
+    void pause(bool paused);
+
+    /// Clears buffer data (fills with 0)
+    void clear();
+
+private:
+    unsigned _numSamples;
+    bool _paused;
+
+    bool _hasx;
+    ResizableBuffer* xData;
+    QList<StreamChannel*> channels;
+
+    ChannelInfoModel _infoModel;
+
+    /**
+     * Applies gain and offset to given pack.
+     *
+     * Caller is responsible for deleting returned `SamplePack`.
+     *
+     * @note Should be called only when gain or offset is enabled. Guard with
+     * `ChannelInfoModel::gainOrOffsetEn()`.
+     *
+     * @param pack input data
+     * @return modified data
+     */
+    const SamplePack* applyGainOffset(const SamplePack& pack) const;
+};
+
+
+#endif // STREAM_H