export_channel.h

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/*
 * Copyright (C) 2008-2012 Sakari Bergen <sakari.bergen@beatwaves.net>
 * Copyright (C) 2009-2011 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2009-2011 David Robillard <d@drobilla.net>
 * Copyright (C) 2009-2017 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2017-2022 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 __ardour_export_channel_h__
#define __ardour_export_channel_h__
 
#include <list>
#include <memory>
#include <set>
 
#include <boost/scoped_array.hpp>
 
#include "pbd/ringbuffer.h"
#include "pbd/signals.h"
 
#include "ardour/audio_buffer.h"
#include "ardour/buffer_set.h"
#include "ardour/export_pointers.h"
#include "ardour/fixed_delay.h"
#include "ardour/midi_buffer.h"
 
namespace ARDOUR {
 
class Session;
class AudioTrack;
class AudioPort;
class AudioRegion;
class CapturingProcessor;
class MidiPort;
 
class LIBARDOUR_API ExportChannel : public boost::less_than_comparable<ExportChannel>
{
public:
        virtual ~ExportChannel () {}
 
        virtual samplecnt_t common_port_playback_latency () const { return 0; }
        virtual void prepare_export (samplecnt_t max_samples, sampleoffset_t common_latency) {}
 
        virtual void read (Buffer const*&, samplecnt_t samples) const = 0;
 
        virtual bool empty () const = 0;
 
        virtual bool audio () const { return true; }
        virtual bool midi () const { return false; }
 
        virtual std::string state_node_name () const = 0;
 
        virtual void get_state (XMLNode* node) const = 0;
 
        virtual void set_state (XMLNode* node, Session& session) = 0;
 
        // Operator< must be defined for usage in e.g. std::map or std::set to disallow duplicates when necessary
        virtual bool operator< (ExportChannel const& other) const = 0;
};
 
class LIBARDOUR_API PortExportChannel : public ExportChannel
{
public:
        typedef std::set<std::weak_ptr<AudioPort>, std::owner_less<std::weak_ptr<AudioPort>>> PortSet;
 
        PortExportChannel ();
        ~PortExportChannel ();
 
        samplecnt_t common_port_playback_latency () const;
        void        prepare_export (samplecnt_t max_samples, sampleoffset_t common_latency);
 
        void read (Buffer const*&, samplecnt_t samples) const;
 
        bool empty () const { return ports.empty (); }
 
        std::string state_node_name () const { return "PortExportChannel"; }
 
        void get_state (XMLNode* node) const;
        void set_state (XMLNode* node, Session& session);
 
        bool operator< (ExportChannel const& other) const;
 
        void add_port (std::weak_ptr<AudioPort> port) { ports.insert (port); }
        PortSet const& get_ports () const { return ports; }
 
private:
        PortSet                                             ports;
        samplecnt_t                                         _buffer_size;
        boost::scoped_array<Sample>                         _buffer;
        mutable AudioBuffer                                 _buf;
        std::list<std::shared_ptr<PBD::RingBuffer<Sample>>> _delaylines;
};
 
class LIBARDOUR_API PortExportMIDI : public ExportChannel
{
public:
        PortExportMIDI ();
        ~PortExportMIDI ();
 
        /* ExportChannel interface */
        samplecnt_t common_port_playback_latency () const;
        void        prepare_export (samplecnt_t max_samples, sampleoffset_t common_latency);
 
        void read (Buffer const*&, samplecnt_t samples) const;
 
        bool empty () const { return _port.expired (); }
 
        bool audio () const { return false; }
        bool midi () const { return true; }
 
        std::string state_node_name () const { return "PortExportMIDI"; }
 
        void get_state (XMLNode* node) const;
        void set_state (XMLNode* node, Session& session);
 
        bool operator< (ExportChannel const& other) const;
 
        std::shared_ptr<MidiPort> port () const { return _port.lock (); }
 
        void set_port (std::weak_ptr<MidiPort> port)
        {
                _port = port;
        }
 
private:
        std::weak_ptr<MidiPort> _port;
        mutable FixedDelay      _delayline;
        mutable MidiBuffer      _buf;
};
 
class LIBARDOUR_API RegionExportChannelFactory
{
public:
        enum Type {
                None,
                Raw,
                Fades,
        };
 
        RegionExportChannelFactory (Session* session, AudioRegion const& region, AudioTrack& track, Type type);
        ~RegionExportChannelFactory ();
 
        ExportChannelPtr create (uint32_t channel);
 
        void read (uint32_t channel, Buffer const*&, samplecnt_t samples_to_read);
 
private:
        int new_cycle_started (samplecnt_t)
        {
                buffers_up_to_date = false;
                return 0;
        }
 
        void update_buffers (samplecnt_t samples);
 
        AudioRegion const& region;
 
        Type        type;
        samplecnt_t samples_per_cycle;
        size_t      n_channels;
        BufferSet   buffers;
        bool        buffers_up_to_date;
        samplepos_t region_start;
        samplepos_t position;
 
        boost::scoped_array<Sample> mixdown_buffer;
        boost::scoped_array<Sample> gain_buffer;
 
        PBD::ScopedConnection export_connection;
};
 
class LIBARDOUR_API RegionExportChannel : public ExportChannel
{
        friend class RegionExportChannelFactory;
 
public:
        void read (Buffer const*& buf, samplecnt_t samples_to_read) const
        {
                factory.read (channel, buf, samples_to_read);
        }
 
        std::string state_node_name () const { return "RegionExportChannel"; }
 
        void get_state (XMLNode* /*node*/) const {};
        void set_state (XMLNode* /*node*/, Session& /*session*/){};
 
        bool empty () const { return false; }
 
        // Region export should never have duplicate channels, so there need not be any semantics here
        bool operator< (ExportChannel const& other) const
        {
                return this < &other;
        }
 
private:
        RegionExportChannel (RegionExportChannelFactory& factory, uint32_t channel)
                : factory (factory)
                , channel (channel)
        {
        }
 
        RegionExportChannelFactory& factory;
        uint32_t                    channel;
};
 
class LIBARDOUR_API RouteExportChannel : public ExportChannel
{
        class ProcessorRemover; // fwd declaration
 
public:
        RouteExportChannel (std::shared_ptr<CapturingProcessor> processor,
                            DataType                            type,
                            size_t                              channel,
                            std::shared_ptr<ProcessorRemover>   remover);
 
        ~RouteExportChannel ();
 
        static void create_from_route (std::list<ExportChannelPtr>& result, std::shared_ptr<Route> route);
        static void create_from_state (std::list<ExportChannelPtr>& result, Session&, XMLNode*);
 
public: // ExportChannel interface
        void prepare_export (samplecnt_t max_samples, sampleoffset_t common_latency);
 
        void read (Buffer const*&, samplecnt_t samples) const;
 
        bool empty () const { return false; }
 
        bool audio () const;
        bool midi () const;
 
        std::shared_ptr<Route> route () const { return _remover->route (); }
 
        std::string state_node_name () const { return "RouteExportChannel"; }
 
        void get_state (XMLNode* node) const;
        void set_state (XMLNode* node, Session& session);
 
        bool operator< (ExportChannel const& other) const;
 
private:
        // Removes the processor from the track when deleted
        class ProcessorRemover
        {
        public:
                ProcessorRemover (std::shared_ptr<Route> route, std::shared_ptr<CapturingProcessor> processor)
                        : _route (route)
                        , _processor (processor)
                {
                }
                ~ProcessorRemover ();
 
                std::shared_ptr<Route> route () const { return _route; }
 
        private:
                std::shared_ptr<Route>              _route;
                std::shared_ptr<CapturingProcessor> _processor;
        };
 
        std::shared_ptr<CapturingProcessor> _processor;
 
        DataType _type;
        size_t   _channel;
 
        // Each channel keeps a ref to the remover. Last one alive
        // will cause the processor to be removed on deletion.
        std::shared_ptr<ProcessorRemover> _remover;
};
 
} // namespace ARDOUR
 
#endif