libs/ardour/audio_port.cc

   1 /*
   2     Copyright (C) 2006 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 #include <cassert>
  20 #include "ardour/audio_port.h"
  21 #include "ardour/audioengine.h"
  22 #include "ardour/data_type.h"
  23 #include "ardour/audio_buffer.h"
  24
  25 using namespace ARDOUR;
  26 using namespace std;
  27
  28 AudioPort::AudioPort (const std::string& name, Flags flags)
  29         : Port (name, DataType::AUDIO, flags)
  30         , _buffer (new AudioBuffer (0))
  31 {
  32         assert (name.find_first_of (':') == string::npos);
  33 }
  34
  35 AudioPort::~AudioPort ()
  36 {
  37         delete _buffer;
  38 }
  39
  40 void
  41 AudioPort::cycle_start (nframes_t nframes)
  42 {
  43         /* caller must hold process lock */
  44
  45         /* get_buffer() must only be run on outputs here in cycle_start().
  46
  47            Inputs must be done in the correct processing order, which
  48            requires interleaving with route processing. that will
  49            happen when Port::get_buffer() is called.
  50         */
  51
  52         if (sends_output()) {
  53
  54                 /* Notice that cycle_start() is always run with the *entire* process cycle frame count,
  55                    so we do not bother to apply _port_offset here - we always want the address of the
  56                    entire JACK port buffer. We are not collecting data here - just noting the
  57                    address where we will write data later in the process cycle.
  58                 */
  59
  60                 _buffer->set_data ((Sample *) jack_port_get_buffer (_jack_port, nframes), nframes);
  61                 _buffer->prepare ();
  62         }
  63 }
  64
  65 void
  66 AudioPort::cycle_end (nframes_t nframes)
  67 {
  68         if (sends_output() && !_buffer->written()) {
  69                 _buffer->silence (nframes);
  70         }
  71 }
  72
  73 void
  74 AudioPort::cycle_split ()
  75 {
  76 }
  77
  78 AudioBuffer&
  79 AudioPort::get_audio_buffer (nframes_t nframes, nframes_t offset)
  80 {
  81         /* caller must hold process lock */
  82
  83         if (receives_input ()) {
  84
  85                 /* Get a pointer to the audio data @ offset + _port_offset within the JACK port buffer and store
  86                    it in our _buffer member.
  87
  88                    Note that offset is expected to be zero in almost all cases.
  89                 */
  90
  91                 _buffer->set_data ((Sample *) jack_port_get_buffer (_jack_port, nframes) + offset + _port_offset, nframes);
  92         }
  93
  94         /* output ports set their _buffer data information during ::cycle_start()
  95          */
  96
  97         return *_buffer;
  98 }
  99
 100 size_t
 101 AudioPort::raw_buffer_size (nframes_t nframes) const
 102 {
 103         return nframes * sizeof (Sample);
 104 }
 105