/* Copyright (C) 2013 Paul Davis 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef __libardour_port_engine_h__ #define __libardour_port_engine_h__ #include #include #include #include "ardour/data_type.h" #include "ardour/libardour_visibility.h" #include "ardour/types.h" namespace ARDOUR { class PortManager; /** PortEngine is an abstract base class that defines the functionality * required by Ardour. * * A Port is basically an endpoint for a datastream (which can either be * continuous, like audio, or event-based, like MIDI). Ports have buffers * associated with them into which data can be written (if they are output * ports) and from which data can be read (if they input ports). Ports can be * connected together so that data written to an output port can be read from * an input port. These connections can be 1:1, 1:N OR N:1. * * Ports may be associated with software only, or with hardware. Hardware * related ports are often referred to as physical, and correspond to some * relevant physical entity on a hardware device, such as an audio jack or a * MIDI connector. Physical ports may be potentially asked to monitor their * inputs, though some implementations may not support this. * * Most physical ports will also be considered "terminal", which means that * data delivered there or read from there will go to or comes from a system * outside of the PortEngine implementation's control (e.g. the analog domain * for audio, or external MIDI devices for MIDI). Non-physical ports can also * be considered "terminal". For example, the output port of a software * synthesizer is a terminal port, because the data contained in its buffer * does not and cannot be considered to come from any other port - it is * synthesized by its owner. * * Ports also have latency associated with them. Each port has a playback * latency and a capture latency: * * capture latency: how long since the data read from the buffer of a * port arrived at at a terminal port. The data will have * come from the "outside world" if the terminal port is also * physical, or will have been synthesized by the entity that * owns the terminal port. * * playback latency: how long until the data written to the buffer of * port will reach a terminal port. * * * For more detailed questions about the PortEngine API, consult the JACK API * documentation, on which this entire object is based. */ class LIBARDOUR_API PortEngine { public: PortEngine (PortManager& pm) : manager (pm) {} virtual ~PortEngine() {} /** Return a private, type-free pointer to any data * that might be useful to a concrete implementation */ virtual void* private_handle() const = 0; /* We use void* here so that the API can be defined for any implementation. * * We could theoretically use a template (PortEngine) and define * PortHandle as T, but this complicates the desired inheritance * pattern in which FooPortEngine handles things for the Foo API, * rather than being a derivative of PortEngine. */ typedef void* PortHandle; /** Return the name of this process as used by the port manager * when naming ports. */ virtual const std::string& my_name() const = 0; /** Return true if the underlying mechanism/API is still available * for us to utilize. return false if some or all of the AudioBackend * API can no longer be effectively used. */ virtual bool available() const = 0; /** Return the maximum size of a port name */ virtual uint32_t port_name_size() const = 0; /** Returns zero if the port referred to by @param port was set to @param * name. Return non-zero otherwise. */ virtual int set_port_name (PortHandle port, const std::string& name) = 0; /** Return the name of the port referred to by @param port. If the port * does not exist, return an empty string. */ virtual std::string get_port_name (PortHandle) const = 0; /** Return the port-property value and type for a given key. * (eg query a human readable port name) * * The API follows jack_get_property(): * * @param key The key of the property to retrieve * @param value Set to the value of the property if found * @param type The type of the property if set ( * Type of data, either a MIME type or URI. * If type is empty, the data is assumed to be a UTF-8 encoded string. * * @return 0 on success, -1 if the @p subject has no @p key property. * * for available keys, see * https://github.com/jackaudio/headers/blob/master/metadata.h * https://github.com/drobilla/jackey/blob/master/jackey.h */ virtual int get_port_property (PortHandle, const std::string& key, std::string& value, std::string& type) const { return -1; } /** Set the port-property value and type for a given key * * The API follows jack_set_property(): * @param key The key of the property. * @param value The value of the property. * @param type The type of the property. * * @return 0 on success, -1 on error */ virtual int set_port_property (PortHandle, const std::string& key, const std::string& value, const std::string& type) { return -1; } /** Return a reference to a port with the fullname @param name. Return * an "empty" PortHandle (analogous to a null pointer) if no such port exists. */ virtual PortHandle get_port_by_name (const std::string&) const = 0; /** Find the set of ports whose names, types and flags match * specified values, place the names of each port into @param ports, * and return the count of the number found. * * To avoid selecting by name, pass an empty string for @param * port_name_pattern. * * To avoid selecting by type, pass DataType::NIL as @param type. * * To avoid selecting by flags, pass PortFlags (0) as @param flags. */ virtual int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector& ports) const = 0; /** Return the Ardour data type handled by the port referred to by @param * port. Returns DataType::NIL if the port does not exist. */ virtual DataType port_data_type (PortHandle port) const = 0; /** Create a new port whose fullname will be the conjuction of my_name(), * ":" and @param shortname. The port will handle data specified by @param * type and will have the flags given by @param flags. If successfull, * return a reference to the port, otherwise return a null pointer. */ virtual PortHandle register_port (const std::string& shortname, ARDOUR::DataType type, ARDOUR::PortFlags flags) = 0; /* Destroy the port referred to by @param port, including all resources * associated with it. This will also disconnect @param port from any ports it * is connected to. */ virtual void unregister_port (PortHandle) = 0; /* Connection management */ /** Ensure that data written to the port named by @param src will be * readable from the port named by @param dst. Return zero on success, * non-zero otherwise. */ virtual int connect (const std::string& src, const std::string& dst) = 0; /** Remove any existing connection between the ports named by @param src and * @param dst. Return zero on success, non-zero otherwise. */ virtual int disconnect (const std::string& src, const std::string& dst) = 0; /** Ensure that data written to the port referenced by @param portwill be * readable from the port named by @param dst. Return zero on success, * non-zero otherwise. */ virtual int connect (PortHandle src, const std::string& dst) = 0; /** Remove any existing connection between the port referenced by @param src and * the port named @param dst. Return zero on success, non-zero otherwise. */ virtual int disconnect (PortHandle src, const std::string& dst) = 0; /** Remove all connections between the port referred to by @param port and * any other ports. Return zero on success, non-zero otherwise. */ virtual int disconnect_all (PortHandle port) = 0; /** Return true if the port referred to by @param port has any connections * to other ports. Return false otherwise. */ virtual bool connected (PortHandle port, bool process_callback_safe = true) = 0; /** Return true if the port referred to by @param port is connected to * the port named by @param name. Return false otherwise. */ virtual bool connected_to (PortHandle, const std::string& name, bool process_callback_safe = true) = 0; /** Return true if the port referred to by @param port has any connections * to ports marked with the PortFlag IsPhysical. Return false otherwise. */ virtual bool physically_connected (PortHandle port, bool process_callback_safe = true) = 0; /** Place the names of all ports connected to the port named by @param * ports into @param names, and return the number of connections. */ virtual int get_connections (PortHandle port, std::vector& names, bool process_callback_safe = true) = 0; /* MIDI */ /** Retrieve a MIDI event from the data at @param port_buffer. The event number to be retrieved is given by @param event_index (a value of zero indicates that the first event in the port_buffer should be retrieved). * * The data associated with the event will be copied into the buffer at * @param buf and the number of bytes written will be stored in @param * size. The timestamp of the event (which is always relative to the start * of the current process cycle, in samples) will be stored in @param * timestamp */ virtual int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t** buf, void* port_buffer, uint32_t event_index) = 0; /** Place a MIDI event consisting of @param size bytes copied from the data * at @param buf into the port buffer referred to by @param * port_buffer. The MIDI event will be marked with a time given by @param * timestamp. Return zero on success, non-zero otherwise. * * Events must be added monotonically to a port buffer. An attempt to * add a non-monotonic event (e.g. out-of-order) will cause this method * to return a failure status. */ virtual int midi_event_put (void* port_buffer, pframes_t timestamp, const uint8_t* buffer, size_t size) = 0; /** Return the number of MIDI events in the data at @param port_buffer */ virtual uint32_t get_midi_event_count (void* port_buffer) = 0; /** Clear the buffer at @param port_buffer of all MIDI events. * * After a call to this method, an immediate, subsequent call to * get_midi_event_count() with the same @param port_buffer argument must * return zero. */ virtual void midi_clear (void* port_buffer) = 0; /* Monitoring */ /** Return true if the implementation can offer input monitoring. * * Input monitoring involves the (selective) routing of incoming data * to an outgoing data stream, without the data being passed to the CPU. * * Only certain audio hardware can provide this, and only certain audio * APIs can offer it. */ virtual bool can_monitor_input() const = 0; /** Increment or decrement the number of requests to monitor the input * of the hardware channel represented by the port referred to by @param * port. * * If the number of requests rises above zero, input monitoring will * be enabled (if can_monitor_input() returns true for the implementation). * * If the number of requests falls to zero, input monitoring will be * disabled (if can_monitor_input() returns true for the implementation) */ virtual int request_input_monitoring (PortHandle port, bool yn) = 0; /* Force input monitoring of the hardware channel represented by the port * referred to by @param port to be on or off, depending on the true/false * status of @param yn. The request count is ignored when using this * method, so if this is called with yn set to false, input monitoring will * be disabled regardless of the number of requests to enable it. */ virtual int ensure_input_monitoring (PortHandle port, bool yn) = 0; /** Return true if input monitoring is enabled for the hardware channel * represented by the port referred to by @param port. Return false * otherwise. */ virtual bool monitoring_input (PortHandle port) = 0; /* Latency management */ /** Set the latency range for the port referred to by @param port to @param * r. The playback range will be set if @param for_playback is true, * otherwise the capture range will be set. */ virtual void set_latency_range (PortHandle port, bool for_playback, LatencyRange r) = 0; /** Return the latency range for the port referred to by @param port. * The playback range will be returned if @param for_playback is true, * otherwise the capture range will be returned. */ virtual LatencyRange get_latency_range (PortHandle port, bool for_playback) = 0; /* Discovering physical ports */ /** Return true if the port referred to by @param port has the IsPhysical * flag set. Return false otherwise. */ virtual bool port_is_physical (PortHandle port) const = 0; /** Store into @param names the names of all ports with the IsOutput and * IsPhysical flag set, that handle data of type @param type. * * This can be used to discover outputs associated with hardware devices. */ virtual void get_physical_outputs (DataType type, std::vector& names) = 0; /** Store into @param names the names of all ports with the IsInput and * IsPhysical flags set, that handle data of type @param type. * * This can be used to discover inputs associated with hardware devices. */ virtual void get_physical_inputs (DataType type, std::vector& names) = 0; /** Return the total count (possibly mixed between different data types) of the number of ports with the IsPhysical and IsOutput flags set. */ virtual ChanCount n_physical_outputs () const = 0; /** Return the total count (possibly mixed between different data types) of the number of ports with the IsPhysical and IsInput flags set. */ virtual ChanCount n_physical_inputs () const = 0; /** Return the address of the memory area where data for the port can be * written (if the port has the PortFlag IsOutput set) or read (if the port * has the PortFlag IsInput set). * * The return value is untyped because buffers containing different data * depending on the port type. */ virtual void* get_buffer (PortHandle, pframes_t) = 0; /* MIDI ports (the ones in libmidi++) need this to be able to correctly * schedule MIDI events within their buffers. It is a bit odd that we * expose this here, because it is also exposed by AudioBackend, but they * only have access to a PortEngine object, not an AudioBackend. * * Return the time according to the sample clock in use when the current * buffer process cycle began. * * XXX to be removed after some more design cleanup. */ virtual framepos_t sample_time_at_cycle_start () = 0; protected: PortManager& manager; }; } #endif /* __libardour_port_engine_h__ */