alsa_audiobackend.h

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/*
 * Copyright (C) 2014-2019 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2015-2018 Paul Davis <paul@linuxaudiosystems.com>
 *
 * 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_alsa_audiobackend_h__
#define __libbackend_alsa_audiobackend_h__
 
#include <cstdint>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <vector>
 
#include <pthread.h>
 
 
#include "pbd/natsort.h"
#include "pbd/rcu.h"
 
#include "ardour/audio_backend.h"
#include "ardour/dsp_load_calculator.h"
#include "ardour/port_engine_shared.h"
#include "ardour/system_exec.h"
#include "ardour/types.h"
 
#include "ardouralsautil/deviceinfo.h"
 
#include "alsa_rawmidi.h"
#include "alsa_sequencer.h"
#include "alsa_slave.h"
#include "zita-alsa-pcmi.h"
 
namespace ARDOUR {
 
class AlsaAudioBackend;
 
class AlsaMidiEvent : public BackendMIDIEvent {
        public:
                AlsaMidiEvent (const pframes_t timestamp, const uint8_t* data, size_t size);
                AlsaMidiEvent (const AlsaMidiEvent& other);
                size_t size () const { return _size; };
                pframes_t timestamp () const { return _timestamp; };
                const uint8_t* data () const { return _data; };
        private:
                size_t _size;
                pframes_t _timestamp;
                uint8_t _data[MaxAlsaMidiEventSize];
};
 
typedef std::vector<AlsaMidiEvent> AlsaMidiBuffer;
 
class AlsaAudioPort : public BackendPort {
        public:
                AlsaAudioPort (AlsaAudioBackend &b, const std::string&, PortFlags);
                ~AlsaAudioPort ();
 
                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 AlsaAudioPort
 
class AlsaMidiPort : public BackendPort {
        public:
                AlsaMidiPort (AlsaAudioBackend &b, const std::string&, PortFlags);
                ~AlsaMidiPort ();
 
                DataType type () const { return DataType::MIDI; };
 
                void* get_buffer (pframes_t nframes);
                const AlsaMidiBuffer * const_buffer () const { return & _buffer[_bufperiod]; }
 
                void next_period() { if (_n_periods > 1) { get_buffer(0); _bufperiod = (_bufperiod + 1) % _n_periods; } }
                void set_n_periods(int n) { if (n > 0 && n < 4) { _n_periods = n; } }
 
        private:
                AlsaMidiBuffer _buffer[3];
                int _n_periods;
                int _bufperiod;
}; // class AlsaMidiPort
 
class AlsaDeviceReservation
{
        public:
                AlsaDeviceReservation ();
                AlsaDeviceReservation (const char* device_name);
                ~AlsaDeviceReservation ();
 
                bool acquire_device (const char* device_name, bool silent = false);
                void release_device ();
 
        private:
                ARDOUR::SystemExec* _device_reservation;
                PBD::ScopedConnectionList _reservation_connection;
                void reservation_stdout (std::string, size_t);
                bool _reservation_succeeded;
};
 
class AlsaAudioBackend : public AudioBackend, public PortEngineSharedImpl
{
        public:
                AlsaAudioBackend (AudioEngine& e, AudioBackendInfo& info);
                ~AlsaAudioBackend ();
 
                /* AUDIOBACKEND API */
 
                std::string name () const;
                bool is_realtime () const;
 
                bool use_separate_input_and_output_devices () const { return true; }
                bool match_input_output_devices_or_none () const { return false; }
                bool can_set_period_size () const { return true; }
 
                std::vector<DeviceStatus> enumerate_devices () const;
                std::vector<DeviceStatus> enumerate_input_devices () const;
                std::vector<DeviceStatus> enumerate_output_devices () const;
                std::vector<float> available_sample_rates (const std::string& device) const;
                std::vector<float> available_sample_rates2 (const std::string&, const std::string&) const;
                std::vector<uint32_t> available_buffer_sizes (const std::string& device) const;
                std::vector<uint32_t> available_buffer_sizes2 (const std::string&, const std::string&) const;
                std::vector<uint32_t> available_period_sizes (const std::string& driver, 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;
                bool can_change_systemic_latency_when_running () const { return true; }
 
                bool can_request_update_devices () { return true; }
                bool update_devices () { return true; }
 
                int set_device_name (const std::string&);
                int set_input_device_name (const std::string&);
                int set_output_device_name (const std::string&);
                int set_sample_rate (float);
                int set_buffer_size (uint32_t);
                int set_peridod_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);
                int set_systemic_midi_output_latency (std::string const, uint32_t);
 
                int reset_device () { return 0; };
 
                /* Retrieving parameters */
                std::string  device_name () const;
                std::string  input_device_name () const;
                std::string  output_device_name () const;
                float        sample_rate () const;
                uint32_t     buffer_size () const;
                uint32_t     period_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;
                uint32_t     systemic_midi_output_latency (std::string const) const;
 
                bool can_set_systemic_midi_latencies () const { return true; }
 
                /* External control app */
                std::string control_app_name () const { return std::string (); }
                void launch_control_app () {}
 
                /* MIDI */
                std::vector<std::string> enumerate_midi_options () const;
                int set_midi_option (const std::string&);
                std::string midi_option () const;
 
                std::vector<DeviceStatus> enumerate_midi_devices () const;
                int set_midi_device_enabled (std::string const, bool);
                bool midi_device_enabled (std::string const) const;
 
                /* 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;
                Alsa_pcmi *_pcmi;
 
                bool  _run; /* keep going or stop, ardour thread */
                bool  _active; /* is running, process thread */
                bool  _freewheel;
                bool  _freewheeling;
                bool  _measure_latency;
 
                uint64_t _last_process_start;
 
                static std::vector<std::string> _midi_options;
                static std::vector<AudioBackend::DeviceStatus> _input_audio_device_status;
                static std::vector<AudioBackend::DeviceStatus> _output_audio_device_status;
                static std::vector<AudioBackend::DeviceStatus> _duplex_audio_device_status;
                static std::vector<AudioBackend::DeviceStatus> _midi_device_status;
                static ARDOUR::ALSADeviceInfo _input_audio_device_info;
                static ARDOUR::ALSADeviceInfo _output_audio_device_info;
 
                mutable std::string _input_audio_device;
                mutable std::string _output_audio_device;
                std::string _midi_driver_option;
 
                /* audio device reservation */
                AlsaDeviceReservation _device_reservation;
 
                /* audio settings */
                float  _samplerate;
                size_t _samples_per_period;
                size_t _periods_per_cycle;
                static size_t _max_buffer_size;
 
                uint32_t _systemic_audio_input_latency;
                uint32_t _systemic_audio_output_latency;
 
                /* midi settings */
                struct AlsaMidiDeviceInfo {
                        bool     enabled;
                        uint32_t systemic_input_latency;
                        uint32_t systemic_output_latency;
                        AlsaMidiDeviceInfo (bool en = true)
                                : enabled (en)
                                , systemic_input_latency (0)
                                , systemic_output_latency (0)
                        {}
                };
 
                mutable std::map<std::string, struct AlsaMidiDeviceInfo *> _midi_devices;
                struct AlsaMidiDeviceInfo * midi_device_info(std::string const) const;
 
                /* midi device changes */
                void auto_update_midi_devices();
                bool listen_for_midi_device_changes ();
                void stop_listen_for_midi_device_changes ();
                void midi_device_thread ();
                static void* _midi_device_thread (void *arg);
                pthread_t _midi_device_thread_id;
                bool _midi_device_thread_active;
 
                pthread_mutex_t _device_port_mutex;
 
                /* processing */
                float  _dsp_load;
                ARDOUR::DSPLoadCalculator  _dsp_load_calc;
                samplecnt_t _processed_samples;
                pthread_t _main_thread;
 
                /* DLL, track main process callback timing */
                double _t0, _t1;
 
                /* process threads */
                static void* alsa_process_thread (void *);
                std::vector<pthread_t> _threads;
 
                struct ThreadData {
                        AlsaAudioBackend* engine;
                        std::function<void ()> f;
                        size_t stacksize;
 
                        ThreadData (AlsaAudioBackend* 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_audio_ports ();
                int register_system_midi_ports (const std::string device = "");
                void update_system_port_latencies ();
 
                std::vector<AlsaMidiOut *> _rmidi_out;
                std::vector<AlsaMidiIn  *> _rmidi_in;
 
                void update_systemic_audio_latencies ();
                void update_systemic_midi_latencies ();
 
                class AudioSlave : public AlsaDeviceReservation, public AlsaAudioSlave {
                        public:
                                enum DuplexMode {
                                        HalfDuplexIn  = 1,
                                        HalfDuplexOut = 2,
                                        FullDuplex    = 3
                                };
 
                                AudioSlave (
                                                const char*  device,
                                                DuplexMode   duplex,
                                                unsigned int master_rate,
                                                unsigned int master_samples_per_period,
                                                unsigned int slave_rate,
                                                unsigned int slave_samples_per_period,
                                                unsigned int periods_per_cycle);
 
                                ~AudioSlave ();
 
                                bool active; // set in sync with process-cb
                                bool halt;
                                bool dead;
 
                                std::vector<BackendPortPtr> inputs;
                                std::vector<BackendPortPtr> outputs;
 
                                PBD::Signal<void()> UpdateLatency;
                                PBD::ScopedConnection latency_connection;
 
                        protected:
                                void update_latencies (uint32_t, uint32_t);
 
                        private:
                                PBD::ScopedConnection _halted_connection;
                                void halted ();
                };
 
                /* additional re-sampled I/O */
                bool add_slave (const char*  slave_device,
                                unsigned int slave_rate,
                                unsigned int slave_spp,
                                unsigned int slave_ppc,
                                                                                AudioSlave::DuplexMode);
 
                typedef std::vector<AudioSlave*> AudioSlaves;
                AudioSlaves _slaves;
 
}; // class AlsaAudioBackend
 
} // namespace
 
#endif /* __libbackend_alsa_audiobackend_h__ */