pulseaudio_backend.h

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/*
 * Copyright (C) 2019 Robin Gareus <robin@gareus.org>
 *
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef __libbackend_pulse_audiobackend_h__
#define __libbackend_pulse_audiobackend_h__
 
#include <cstdint>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <vector>
 
#include <pthread.h>
 
#include <pulse/pulseaudio.h>
 
#include "pbd/natsort.h"
 
#include "ardour/audio_backend.h"
#include "ardour/dsp_load_calculator.h"
#include "ardour/port_engine_shared.h"
 
#define MaxPulseMidiEventSize (256)
 
namespace ARDOUR {
 
class PulseAudioBackend;
 
class PulseMidiEvent : public BackendMIDIEvent
{
public:
        PulseMidiEvent (const pframes_t timestamp, const uint8_t* data, size_t size);
        PulseMidiEvent (const PulseMidiEvent& other);
 
        size_t size () const { return _size; };
        pframes_t timestamp () const { return _timestamp; };
        const uint8_t* data () const { return _data; };
        const uint8_t* const_data () const { return _data; };
 
private:
        size_t    _size;
        pframes_t _timestamp;
        uint8_t   _data[MaxPulseMidiEventSize];
};
 
typedef std::vector<std::shared_ptr<PulseMidiEvent> > PulseMidiBuffer;
 
 
class PulseAudioPort : public BackendPort
{
public:
        PulseAudioPort (PulseAudioBackend& b, const std::string&, PortFlags);
        ~PulseAudioPort ();
 
        DataType type () const { return DataType::AUDIO; };
 
        Sample* buffer () { return _buffer; }
        const Sample* const_buffer () const { return _buffer; }
        void* get_buffer (pframes_t nframes);
 
private:
        Sample _buffer[8192];
}; // class PulseAudioPort
 
class PulseMidiPort : public BackendPort
{
public:
        PulseMidiPort (PulseAudioBackend& b, const std::string&, PortFlags);
        ~PulseMidiPort ();
 
        DataType type () const { return DataType::MIDI; };
 
        void* get_buffer (pframes_t nframes);
        const PulseMidiBuffer* const_buffer () const { return &_buffer; }
 
private:
        PulseMidiBuffer _buffer;
}; // class PulseMidiPort
 
class PulseAudioBackend : public AudioBackend, public PortEngineSharedImpl
{
public:
        PulseAudioBackend (AudioEngine& e, AudioBackendInfo& info);
        ~PulseAudioBackend ();
 
        /* AUDIOBACKEND API */
 
        std::string name () const;
        bool is_realtime () const;
 
        std::vector<DeviceStatus> enumerate_devices () const;
        std::vector<float> available_sample_rates (const std::string& device) const;
        std::vector<uint32_t> available_buffer_sizes (const std::string& device) const;
 
        bool can_change_sample_rate_when_running () const;
        bool can_change_buffer_size_when_running () const;
        bool can_measure_systemic_latency () const { return false; }
 
        int set_device_name (const std::string&);
        int set_sample_rate (float);
        int set_buffer_size (uint32_t);
        int set_interleaved (bool yn);
        int set_systemic_input_latency (uint32_t);
        int set_systemic_output_latency (uint32_t);
 
        int set_systemic_midi_input_latency (std::string const, uint32_t) { return 0; }
        int set_systemic_midi_output_latency (std::string const, uint32_t) { return 0; }
 
        int reset_device () { return 0; };
 
        /* Retrieving parameters */
        std::string device_name () const;
        float       sample_rate () const;
        uint32_t    buffer_size () const;
        bool        interleaved () const;
        uint32_t    systemic_input_latency () const;
        uint32_t    systemic_output_latency () const;
        uint32_t    systemic_midi_input_latency (std::string const) const { return 0; }
        uint32_t    systemic_midi_output_latency (std::string const) const { return 0; }
 
        /* External control app */
        std::string control_app_name () const;
        void launch_control_app ();
 
        /* MIDI */
        std::vector<std::string>  enumerate_midi_options () const;
        std::vector<DeviceStatus> enumerate_midi_devices () const;
        int                       set_midi_option (const std::string&);
        std::string               midi_option () const;
 
        int set_midi_device_enabled (std::string const, bool) { return 0; }
        bool midi_device_enabled (std::string const) const { return true; }
        bool can_set_systemic_midi_latencies () const { return false; }
 
        /* State Control */
protected:
        int _start (bool for_latency_measurement);
 
public:
        int    stop ();
        int    freewheel (bool);
        float  dsp_load () const;
        size_t raw_buffer_size (DataType t);
 
        /* Process time */
        samplepos_t sample_time ();
        samplepos_t sample_time_at_cycle_start ();
        pframes_t   samples_since_cycle_start ();
 
        int create_process_thread (std::function<void()> func);
        int      join_process_threads ();
        bool     in_process_thread ();
        uint32_t process_thread_count ();
 
        void update_latencies ();
 
        /* PORTENGINE API */
 
        void* private_handle () const;
        const std::string& my_name () const;
 
        /* PortEngine API - forwarded to PortEngineSharedImpl */
 
        bool        port_is_physical (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::port_is_physical (ph); }
        void        get_physical_outputs (DataType type, std::vector<std::string>& results) { PortEngineSharedImpl::get_physical_outputs (type, results); }
        void        get_physical_inputs (DataType type, std::vector<std::string>& results) { PortEngineSharedImpl::get_physical_inputs (type, results); }
        ChanCount   n_physical_outputs () const { return PortEngineSharedImpl::n_physical_outputs (); }
        ChanCount   n_physical_inputs () const { return PortEngineSharedImpl::n_physical_inputs (); }
        uint32_t    port_name_size () const { return PortEngineSharedImpl::port_name_size(); }
        int         set_port_name (PortEngine::PortHandle ph, const std::string& name) { return PortEngineSharedImpl::set_port_name (ph, name); }
        std::string get_port_name (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::get_port_name (ph); }
        PortFlags   get_port_flags (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::get_port_flags (ph); }
        PortEngine::PortPtr  get_port_by_name (std::string const & name) const { return PortEngineSharedImpl::get_port_by_name (name); }
        int         get_port_property (PortEngine::PortHandle ph, const std::string& key, std::string& value, std::string& type) const { return PortEngineSharedImpl::get_port_property (ph, key, value, type); }
        int         set_port_property (PortEngine::PortHandle ph, const std::string& key, const std::string& value, const std::string& type) { return PortEngineSharedImpl::set_port_property (ph, key, value, type); }
        int         get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>& results) const { return PortEngineSharedImpl::get_ports (port_name_pattern, type, flags, results); }
        DataType    port_data_type (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::port_data_type (ph); }
        PortEngine::PortPtr register_port (const std::string& shortname, ARDOUR::DataType type, ARDOUR::PortFlags flags) { return PortEngineSharedImpl::register_port (shortname, type, flags); }
        void        unregister_port (PortHandle ph) { if (!_run) return; PortEngineSharedImpl::unregister_port (ph); }
        int         connect (const std::string& src, const std::string& dst) { return PortEngineSharedImpl::connect (src, dst); }
        int         disconnect (const std::string& src, const std::string& dst) { return PortEngineSharedImpl::disconnect (src, dst); }
        int         connect (PortEngine::PortHandle ph, const std::string& other) { return PortEngineSharedImpl::connect (ph, other); }
        int         disconnect (PortEngine::PortHandle ph, const std::string& other) { return PortEngineSharedImpl::disconnect (ph, other); }
        int         disconnect_all (PortEngine::PortHandle ph) { return PortEngineSharedImpl::disconnect_all (ph); }
        bool        connected (PortEngine::PortHandle ph, bool process_callback_safe) { return PortEngineSharedImpl::connected (ph, process_callback_safe); }
        bool        connected_to (PortEngine::PortHandle ph, const std::string& other, bool process_callback_safe) { return PortEngineSharedImpl::connected_to (ph, other, process_callback_safe); }
        bool        physically_connected (PortEngine::PortHandle ph, bool process_callback_safe) { return PortEngineSharedImpl::physically_connected (ph, process_callback_safe); }
        int         get_connections (PortEngine::PortHandle ph, std::vector<std::string>& results, bool process_callback_safe) { return PortEngineSharedImpl::get_connections (ph, results, process_callback_safe); }
 
        /* MIDI */
        int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t const** buf, void* port_buffer, uint32_t event_index);
        int midi_event_put (void* port_buffer, pframes_t timestamp, const uint8_t* buffer, size_t size);
        uint32_t get_midi_event_count (void* port_buffer);
        void midi_clear (void* port_buffer);
 
        /* Monitoring */
 
        bool can_monitor_input () const;
        int  request_input_monitoring (PortHandle, bool);
        int  ensure_input_monitoring (PortHandle, bool);
        bool monitoring_input (PortHandle);
 
        /* Latency management */
 
        void set_latency_range (PortHandle, bool for_playback, LatencyRange);
        LatencyRange get_latency_range (PortHandle, bool for_playback);
 
        /* Getting access to the data buffer for a port */
 
        void* get_buffer (PortHandle, pframes_t);
 
        void* main_process_thread ();
 
private:
        std::string _instance_name;
 
        /* pulse */
        struct pa_stream*            p_stream;
        struct pa_context*           p_context;
        struct pa_threaded_mainloop* p_mainloop;
 
        int  init_pulse ();
        void close_pulse (bool unlock = false);
        int  sync_pulse (pa_operation*);
        bool cork_pulse (bool);
 
        static void context_state_cb (pa_context*, void*);
        static void stream_state_cb (pa_stream*, void*);
        static void stream_request_cb (pa_stream*, size_t, void*);
        static void stream_latency_update_cb (pa_stream*, void*);
        static void stream_xrun_cb (pa_stream*, void*);
        static void stream_operation_cb (pa_stream*, int, void*);
 
        bool _operation_succeeded;
 
        bool _run;    /* keep going or stop, ardour thread */
        bool _active; /* is running, process thread */
        bool _freewheel;
        bool _freewheeling;
 
        uint64_t _last_process_start;
 
        /* audio settings */
        float    _samplerate;
        size_t   _samples_per_period;
        uint32_t _systemic_audio_output_latency;
 
        static const size_t _max_buffer_size;
 
        /* processing */
        float                     _dsp_load;
        ARDOUR::DSPLoadCalculator _dsp_load_calc;
        samplecnt_t               _processed_samples;
        pthread_t                 _main_thread;
 
        /* process threads */
        static void*           pulse_process_thread (void*);
        std::vector<pthread_t> _threads;
 
        struct ThreadData {
                PulseAudioBackend*      engine;
                std::function<void()> f;
                size_t                  stacksize;
 
                ThreadData (PulseAudioBackend* e, std::function<void()> fp, size_t stacksz)
                        : engine (e), f (fp), stacksize (stacksz) {}
        };
 
        /* port engine */
        BackendPort* port_factory (std::string const & name, ARDOUR::DataType dt, ARDOUR::PortFlags flags);
        int  register_system_ports ();
 
}; // class PulseAudioBackend
 
} // namespace
 
#endif /* __libbackend_pulse_audiobackend_h__ */