Sample Track Recording with Jack backend (#7567)

Enable the `AudioJack` to take recorded input and push it to the `AudioEngine`. This adds functionality for `AudioJack` which already exists for `AudioSdl` and `AudioPortAudio`. Note that sample track recording in the LMMS core is not completed before #7786 .

This PR also removes the reading and saving of the channel number configuration in several places as it will default to `DEFAULT_CHANNELS` all the time anyway.

Co-authored-by: Johannes Lorenz <j.git@lorenz-ho.me>
Co-authored-by: Michael Gregorius <michael.gregorius.git@arcor.de>

include/AudioJack.h

@@ -53,11 +53,6 @@ namespace lmms
 
 class MidiJack;
 
-namespace gui
-{
-class LcdSpinBox;
-}
-
 
 class AudioJack : public QObject, public AudioDevice
 {
@@ -82,13 +77,10 @@ public:
 	{
 	public:
 		setupWidget(QWidget* parent);
-		~setupWidget() override;
-
 		void saveSettings() override;
 
 	private:
 		QLineEdit* m_clientName;
-		gui::LcdSpinBox* m_channels;
 	};
 
 private slots:
@@ -96,6 +88,7 @@ private slots:
 
 private:
 	bool initJackClient();
+	void resizeInputBuffer(jack_nframes_t nframes);
 
 	void startProcessing() override;
 	void stopProcessing() override;
@@ -116,8 +109,11 @@ private:
 
 	std::atomic<MidiJack*> m_midiClient;
 	std::vector<jack_port_t*> m_outputPorts;
+	std::vector<jack_port_t*> m_inputPorts;
 	jack_default_audio_sample_t** m_tempOutBufs;
+	std::vector<SampleFrame> m_inputFrameBuffer;
 	SampleFrame* m_outBuf;
+	SampleFrame* m_inBuf;
 
 	f_cnt_t m_framesDoneInCurBuf;
 	f_cnt_t m_framesToDoInCurBuf;