libs/ardour/ardour/export_channel.h

   1 /*
   2     Copyright (C) 2008 Paul Davis
   3     Author: Sakari Bergen
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19 */
  20
  21 #ifndef __ardour_export_channel_h__
  22 #define __ardour_export_channel_h__
  23
  24 #include <set>
  25
  26 #include <boost/signals2.hpp>
  27 #include <boost/shared_ptr.hpp>
  28 #include <boost/operators.hpp>
  29
  30 #include "ardour/audioregion.h"
  31 #include "ardour/buffer_set.h"
  32
  33 namespace ARDOUR {
  34
  35 class Session;
  36 class AudioTrack;
  37 class AudioPort;
  38
  39 /// Export channel base class interface for different source types
  40 class ExportChannel : public boost::less_than_comparable<ExportChannel>
  41 {
  42   public:
  43
  44         virtual ~ExportChannel () {}
  45
  46         virtual void read (Sample * data, nframes_t frames) const = 0;
  47         virtual bool empty () const = 0;
  48
  49         /// Adds state to node passed
  50         virtual void get_state (XMLNode * node) const = 0;
  51
  52         /// Sets state from node passed
  53         virtual void set_state (XMLNode * node, Session & session) = 0;
  54
  55         // Operator< must be defined for usage in e.g. std::map or std::set to disallow duplicates when necessary
  56         virtual bool operator< (ExportChannel const & other) const = 0;
  57 };
  58
  59 /// Safe pointer for storing ExportChannels in ordered STL containers
  60 class ExportChannelPtr : public boost::shared_ptr<ExportChannel>
  61                        , public boost::less_than_comparable<ExportChannel>
  62 {
  63   public:
  64         ExportChannelPtr () {}
  65         template<typename Y> explicit ExportChannelPtr (Y * ptr) : boost::shared_ptr<ExportChannel> (ptr) {}
  66
  67         bool operator< (ExportChannelPtr const & other) const { return **this < *other; }
  68 };
  69
  70 /// Basic export channel that reads from AudioPorts
  71 class PortExportChannel : public ExportChannel
  72 {
  73   public:
  74         typedef std::set<AudioPort *> PortSet;
  75
  76         PortExportChannel () {}
  77
  78         void read (Sample * data, nframes_t frames) const;
  79         bool empty () const { return ports.empty(); }
  80
  81         void get_state (XMLNode * node) const;
  82         void set_state (XMLNode * node, Session & session);
  83
  84         bool operator< (ExportChannel const & other) const;
  85
  86         void add_port (AudioPort * port) { ports.insert (port); }
  87         PortSet const & get_ports () { return ports; }
  88
  89   private:
  90         PortSet ports;
  91 };
  92
  93 /// Handles RegionExportChannels and does actual reading from region
  94 class RegionExportChannelFactory
  95 {
  96   public:
  97         enum Type {
  98                 Raw,
  99                 Fades,
 100                 Processed
 101         };
 102
 103         RegionExportChannelFactory (Session * session, AudioRegion const & region, AudioTrack & track, Type type);
 104         ~RegionExportChannelFactory ();
 105
 106         ExportChannelPtr create (uint32_t channel);
 107         void read (uint32_t channel, Sample * data, nframes_t frames_to_read);
 108
 109   private:
 110
 111         int new_cycle_started (nframes_t) { buffers_up_to_date = false; return 0; }
 112         void update_buffers (nframes_t frames);
 113
 114         AudioRegion const & region;
 115         AudioTrack & track;
 116         Type type;
 117
 118         nframes_t frames_per_cycle;
 119         size_t n_channels;
 120         BufferSet buffers;
 121         bool buffers_up_to_date;
 122         nframes_t region_start;
 123         nframes_t position;
 124
 125         Sample * mixdown_buffer;
 126         Sample * gain_buffer;
 127
 128         PBD::ScopedConnection export_connection;
 129 };
 130
 131 /// Export channel that reads from region channel
 132 class RegionExportChannel : public ExportChannel
 133 {
 134         friend class RegionExportChannelFactory;
 135
 136   public:
 137         void read (Sample * data, nframes_t frames_to_read) const { factory.read (channel, data, frames_to_read); }
 138         void get_state (XMLNode * /*node*/) const {};
 139         void set_state (XMLNode * /*node*/, Session & /*session*/) {};
 140         bool empty () const { return false; }
 141         // Region export should never have duplicate channels, so there need not be any semantics here
 142         bool operator< (ExportChannel const & other) const { return this < &other; }
 143
 144   private:
 145
 146         RegionExportChannel (RegionExportChannelFactory & factory, uint32_t channel)
 147                 : factory (factory)
 148                 , channel (channel)
 149         {}
 150
 151         RegionExportChannelFactory & factory;
 152         uint32_t channel;
 153 };
 154
 155 } // namespace ARDOUR
 156
 157 #endif