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crossfade.cc

/*
    Copyright (C) 2003-2006 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.

*/

#include <sigc++/bind.h>

#include <pbd/stacktrace.h>

#include <ardour/types.h>
#include <ardour/crossfade.h>
#include <ardour/crossfade_compare.h>
#include <ardour/audioregion.h>
#include <ardour/playlist.h>
#include <ardour/utils.h>
#include <ardour/session.h>

#include "i18n.h"
#include <locale.h>

using namespace std;
using namespace ARDOUR;
using namespace PBD;

nframes_t Crossfade::_short_xfade_length = 0;
Change Crossfade::ActiveChanged = new_change();
Change Crossfade::FollowOverlapChanged = new_change();

/* XXX if and when we ever implement parallel processing of the process()
   callback, these will need to be handled on a per-thread basis.
*/

Sample* Crossfade::crossfade_buffer_out = 0;
Sample* Crossfade::crossfade_buffer_in = 0;

void
Crossfade::set_buffer_size (nframes_t sz)
{
      if (crossfade_buffer_out) {
            delete [] crossfade_buffer_out;
            crossfade_buffer_out = 0;
      }

      if (crossfade_buffer_in) {
            delete [] crossfade_buffer_in;
            crossfade_buffer_in = 0;
      }

      if (sz) {
            crossfade_buffer_out = new Sample[sz];
            crossfade_buffer_in = new Sample[sz];
      }
}

bool
Crossfade::operator== (const Crossfade& other)
{
      return (_in == other._in) && (_out == other._out);
}

Crossfade::Crossfade (boost::shared_ptr<AudioRegion> in, boost::shared_ptr<AudioRegion> out, 
                  nframes_t length,
                  nframes_t position,
                  AnchorPoint ap)
      : _fade_in (0.0, 2.0, 1.0), // linear (gain coefficient) => -inf..+6dB
        _fade_out (0.0, 2.0, 1.0) // linear (gain coefficient) => -inf..+6dB
{
      _in = in;
      _out = out;

      _length = length;
      _position = position;
      _anchor_point = ap;

      _follow_overlap = false;

      _active = Config->get_xfades_active ();
      _fixed = true;
            
      initialize ();
}

Crossfade::Crossfade (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioRegion> b, CrossfadeModel model, bool act)
      : _fade_in (0.0, 2.0, 1.0), // linear (gain coefficient) => -inf..+6dB
        _fade_out (0.0, 2.0, 1.0) // linear (gain coefficient) => -inf..+6dB
{
      _in_update = false;
      _fixed = false;

      if (compute (a, b, model)) {
            throw failed_constructor();
      }

      _active = act;

      initialize ();
}

Crossfade::Crossfade (const Playlist& playlist, XMLNode& node)
      :  _fade_in (0.0, 2.0, 1.0), // linear (gain coefficient) => -inf..+6dB
         _fade_out (0.0, 2.0, 1.0) // linear (gain coefficient) => -inf..+6dB
{
      boost::shared_ptr<Region> r;
      XMLProperty* prop;
      LocaleGuard lg (X_("POSIX"));

      /* we have to find the in/out regions before we can do anything else */

      if ((prop = node.property ("in")) == 0) {
            error << _("Crossfade: no \"in\" region in state") << endmsg;
            throw failed_constructor();
      }
      
      PBD::ID id (prop->value());

      if ((r = playlist.find_region (id)) == 0) {
            error << string_compose (_("Crossfade: no \"in\" region %1 found in playlist %2"), id, playlist.name())
                  << endmsg;
            throw failed_constructor();
      }
      
      if ((_in = boost::dynamic_pointer_cast<AudioRegion> (r)) == 0) {
            throw failed_constructor();
      }

      if ((prop = node.property ("out")) == 0) {
            error << _("Crossfade: no \"out\" region in state") << endmsg;
            throw failed_constructor();
      }

      PBD::ID id2 (prop->value());

      if ((r = playlist.find_region (id2)) == 0) {
            error << string_compose (_("Crossfade: no \"out\" region %1 found in playlist %2"), id2, playlist.name())
                  << endmsg;
            throw failed_constructor();
      }
      
      if ((_out = boost::dynamic_pointer_cast<AudioRegion> (r)) == 0) {
            throw failed_constructor();
      }

      _length = 0;
      _active = Config->get_xfades_active();

      initialize();
      
      if (set_state (node)) {
            throw failed_constructor();
      }
}

Crossfade::Crossfade (const Crossfade &orig, boost::shared_ptr<AudioRegion> newin, boost::shared_ptr<AudioRegion> newout)
      : _fade_in(orig._fade_in),
        _fade_out(orig._fade_out)
{
      _active           = orig._active;
      _in_update        = orig._in_update;
      _length           = orig._length;
      _position         = orig._position;
      _anchor_point     = orig._anchor_point;
      _follow_overlap   = orig._follow_overlap;
      _fixed            = orig._fixed;
      
      _in = newin;
      _out = newout;

      // copied from Crossfade::initialize()
      _in_update = false;
      
      _out->suspend_fade_out ();
      _in->suspend_fade_in ();

      overlap_type = _in->coverage (_out->position(), _out->last_frame());
      layer_relation = (int32_t) (_in->layer() - _out->layer());

      // Let's make sure the fade isn't too long
      set_length(_length);
}


Crossfade::~Crossfade ()
{
      notify_callbacks ();
}

void
Crossfade::initialize ()
{
      _in_update = false;
      
      _out->suspend_fade_out ();
      _in->suspend_fade_in ();

      _fade_out.freeze ();
      _fade_out.clear ();

#define EQUAL_POWER_MINUS_3DB
#ifdef  EQUAL_POWER_MINUS_3DB

      _fade_out.add ((_length * 0.000000), 1.000000);
      _fade_out.add ((_length * 0.166667), 0.948859);
      _fade_out.add ((_length * 0.333333), 0.851507);
      _fade_out.add ((_length * 0.500000), 0.707946);
      _fade_out.add ((_length * 0.666667), 0.518174);
      _fade_out.add ((_length * 0.833333), 0.282192);
      _fade_out.add ((_length * 1.000000), 0.000000);

#else // EQUAL_POWER_MINUS_6DB

      _fade_out.add ((_length * 0.000000), 1.000000);
      _fade_out.add ((_length * 0.166667), 0.833033);
      _fade_out.add ((_length * 0.333333), 0.666186);
      _fade_out.add ((_length * 0.500000), 0.499459);
      _fade_out.add ((_length * 0.666667), 0.332853);
      _fade_out.add ((_length * 0.833333), 0.166366);
      _fade_out.add ((_length * 1.000000), 0.000000);
#endif

      _fade_out.thaw ();
      
      _fade_in.freeze ();
      _fade_in.clear ();

#define EQUAL_POWER_MINUS_3DB
#ifdef  EQUAL_POWER_MINUS_3DB

      _fade_in.add ((_length * 0.000000), 0.000000);
      _fade_in.add ((_length * 0.166667), 0.282192);
      _fade_in.add ((_length * 0.333333), 0.518174);
      _fade_in.add ((_length * 0.500000), 0.707946);
      _fade_in.add ((_length * 0.666667), 0.851507);
      _fade_in.add ((_length * 0.833333), 0.948859);
      _fade_in.add ((_length * 1.000000), 1.000000);

#else // EQUAL_POWER_MINUS_SIX_DB

      _fade_in.add ((_length * 0.000000), 0.000000);
      _fade_in.add ((_length * 0.166667), 0.166366);
      _fade_in.add ((_length * 0.333333), 0.332853);
      _fade_in.add ((_length * 0.500000), 0.499459);
      _fade_in.add ((_length * 0.666667), 0.666186);
      _fade_in.add ((_length * 0.833333), 0.833033);
      _fade_in.add ((_length * 1.000000), 1.000000);

#endif

      _fade_in.thaw ();

      overlap_type = _in->coverage (_out->position(), _out->last_frame());
      layer_relation = (int32_t) (_in->layer() - _out->layer());
}     

nframes_t 
Crossfade::read_at (Sample *buf, Sample *mixdown_buffer, 
                float *gain_buffer, nframes_t start, nframes_t cnt, uint32_t chan_n,
                nframes_t read_frames, nframes_t skip_frames)
{
      nframes_t offset;
      nframes_t to_write;

      if (!_active) {
            return 0;
      }

      if (start < _position) {

            /* handle an initial section of the read area that we do not
               cover.
            */

            offset = _position - start;

            if (offset < cnt) {
                  cnt -= offset;
            } else {
                  return 0;
            }
            
            start = _position;
            buf += offset;
            to_write = min (_length, cnt);

      } else {
            
            to_write = min (_length - (start - _position), cnt);
            
      }

      offset = start - _position;

      /* Prevent data from piling up inthe crossfade buffers when reading a transparent region */
      if (!(_out->opaque())) {
            memset (crossfade_buffer_out, 0, sizeof (Sample) * to_write);
      } else if (!(_in->opaque())) {
            memset (crossfade_buffer_in, 0, sizeof (Sample) * to_write);
      }

      _out->read_at (crossfade_buffer_out, mixdown_buffer, gain_buffer, start, to_write, chan_n, read_frames, skip_frames);
      _in->read_at (crossfade_buffer_in, mixdown_buffer, gain_buffer, start, to_write, chan_n, read_frames, skip_frames);

      float* fiv = new float[to_write];
      float* fov = new float[to_write];

      _fade_in.get_vector (offset, offset+to_write, fiv, to_write);
      _fade_out.get_vector (offset, offset+to_write, fov, to_write);

      /* note: although we have not explicitly taken into account the return values
         from _out->read_at() or _in->read_at(), the length() function does this
         implicitly. why? because it computes a value based on the in+out regions'
         position and length, and so we know precisely how much data they could return. 
      */

      for (nframes_t n = 0; n < to_write; ++n) {
            buf[n] = (crossfade_buffer_out[n] * fov[n]) + (crossfade_buffer_in[n] * fiv[n]);
      }

      delete [] fov;
      delete [] fiv;

      return to_write;
}     

OverlapType 
Crossfade::coverage (nframes_t start, nframes_t end) const
{
      nframes_t my_end = _position + _length;

      if ((start >= _position) && (end <= my_end)) {
            return OverlapInternal;
      }
      if ((end >= _position) && (end <= my_end)) {
            return OverlapStart;
      }
      if ((start >= _position) && (start <= my_end)) {
            return OverlapEnd;
      }
      if ((_position >= start) && (_position <= end) && (my_end <= end)) {
            return OverlapExternal;
      }
      return OverlapNone;
}

void
Crossfade::set_active (bool yn)
{
      if (_active != yn) {
            _active = yn;
            StateChanged (ActiveChanged);
      }
}

bool
Crossfade::refresh ()
{
      /* crossfades must be between non-muted regions */
      
      if (_out->muted() || _in->muted()) {
            Invalidated (shared_from_this());
            return false;
      }

      /* Top layer shouldn't be transparent */

      if (!((layer_relation > 0 ? _in : _out)->opaque())) {
            Invalidated (shared_from_this());
            return false;
      }

      /* layer ordering cannot change */

      int32_t new_layer_relation = (int32_t) (_in->layer() - _out->layer());

      if (new_layer_relation * layer_relation < 0) { // different sign, layers rotated 
            Invalidated (shared_from_this());
            return false;
      }

      OverlapType ot = _in->coverage (_out->first_frame(), _out->last_frame());

      if (ot == OverlapNone) {
            Invalidated (shared_from_this());
            return false;
      } 

      bool send_signal;

      if (ot != overlap_type) {

            if (_follow_overlap) {

                  try {
                        compute (_in, _out, Config->get_xfade_model());
                  } 

                  catch (NoCrossfadeHere& err) {
                        Invalidated (shared_from_this());
                        return false;
                  }

                  send_signal = true;

            } else {

                  Invalidated (shared_from_this());
                  return false;
            }

      } else {

            send_signal = update ();
      }

      if (send_signal) {
            StateChanged (BoundsChanged); /* EMIT SIGNAL */
      }

      _in_update = false;

      return true;
}

bool
Crossfade::update ()
{
      nframes_t newlen;
      
      if (_follow_overlap) {
            newlen = _out->first_frame() + _out->length() - _in->first_frame();
      } else {
            newlen = _length;
      }
      
      if (newlen == 0) {
            Invalidated (shared_from_this());
            return false;
      }
      
      _in_update = true;
      
      if ((_follow_overlap && newlen != _length) || (_length > newlen)) {
            
            double factor =  newlen / (double) _length;
            
            _fade_out.x_scale (factor);
            _fade_in.x_scale (factor);
            
            _length = newlen;
      } 
            
      switch (_anchor_point) {
      case StartOfIn:
            _position = _in->first_frame();
            break;
            
      case EndOfIn:
            _position = _in->last_frame() - _length;
            break;
            
      case EndOfOut:
            _position = _out->last_frame() - _length;
      }

      return true;
}

int
Crossfade::compute (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioRegion> b, CrossfadeModel model)
{
      boost::shared_ptr<AudioRegion> top;
      boost::shared_ptr<AudioRegion> bottom;
      nframes_t short_xfade_length;

      short_xfade_length = _short_xfade_length; 

      if (a->layer() < b->layer()) {
            top = b;
            bottom = a;
      } else {
            top = a;
            bottom = b;
      }
      
      /* first check for matching ends */
      
      if (top->first_frame() == bottom->first_frame()) {

            /* Both regions start at the same point */
            
            if (top->last_frame() < bottom->last_frame()) {
                  
                  /* top ends before bottom, so put an xfade
                     in at the end of top.
                  */
                  
                  /* [-------- top ---------- ]
                         * {====== bottom =====================}
                   */

                  _in = bottom;
                  _out = top;

                  if (top->last_frame() < short_xfade_length) {
                        _position = 0;
                  } else {
                        _position = top->last_frame() - short_xfade_length;
                  }

                  _length = min (short_xfade_length, top->length());
                  _follow_overlap = false;
                  _anchor_point = EndOfIn;
                  _active = true;
                  _fixed = true;

            } else {
                  /* top ends after (or same time) as bottom - no xfade
                   */
                  
                  /* [-------- top ------------------------ ]
                         * {====== bottom =====================}
                   */

                  throw NoCrossfadeHere();
            }
            
      } else if (top->last_frame() == bottom->last_frame()) {
            
            /* Both regions end at the same point */
            
            if (top->first_frame() > bottom->first_frame()) {
                  
                  /* top starts after bottom, put an xfade in at the
                     start of top
                  */
                  
                  /*            [-------- top ---------- ]
                         * {====== bottom =====================}
                   */

                  _in = top;
                  _out = bottom;
                  _position = top->first_frame();
                  _length = min (short_xfade_length, top->length());
                  _follow_overlap = false;
                  _anchor_point = StartOfIn;
                  _active = true;
                  _fixed = true;
                  
            } else {
                  /* top starts before bottom - no xfade
                   */

                  /* [-------- top ------------------------ ]
                         *    {====== bottom =====================}
                   */

                  throw NoCrossfadeHere();
            }

      } else {
      
            /* OK, time to do more regular overlapping */

            OverlapType ot = top->coverage (bottom->first_frame(), bottom->last_frame());

            switch (ot) {
            case OverlapNone:
                  /* should be NOTREACHED as a precondition of creating
                     a new crossfade, but we need to handle it here.
                  */
                  throw NoCrossfadeHere();
                  break;
                  
            case OverlapInternal:
            case OverlapExternal:
                  /* should be NOTREACHED because of tests above */
                  throw NoCrossfadeHere();
                  break;
                  
            case OverlapEnd: /* top covers start of bottom but ends within it */

                  /* [---- top ------------------------] 
                   *                { ==== bottom ============ } 
                   */ 

                  _in = bottom;
                  _out = top;
                  _anchor_point = EndOfOut;

                  if (model == FullCrossfade) {
                        _position = bottom->first_frame(); // "{"
                        _length = _out->first_frame() + _out->length() - _in->first_frame();
                        /* leave active alone */
                        _follow_overlap = true;
                  } else {
                        _length = min (short_xfade_length, top->length());
                        _position = top->last_frame() - _length;  // "]" - length 
                        _active = true;
                        _follow_overlap = false;
                        
                  }
                  break;
                  
            case OverlapStart:   /* top starts within bottom but covers bottom's end */

                  /*                   { ==== top ============ } 
                   *   [---- bottom -------------------] 
                   */

                  _in = top;
                  _out = bottom;
                  _position = top->first_frame();
                  _anchor_point = StartOfIn;

                  if (model == FullCrossfade) {
                        _length = _out->first_frame() + _out->length() - _in->first_frame();
                        /* leave active alone */
                        _follow_overlap = true;
                  } else {
                        _length = min (short_xfade_length, top->length());
                        _active = true;
                        _follow_overlap = false;
                        
                  }
                  
                  break;
            }
      }
      
      return 0;
}

XMLNode&
Crossfade::get_state () 
{
      XMLNode* node = new XMLNode (X_("Crossfade"));
      XMLNode* child;
      char buf[64];
      LocaleGuard lg (X_("POSIX"));

      _out->id().print (buf, sizeof (buf));
      node->add_property ("out", buf);
      _in->id().print (buf, sizeof (buf));
      node->add_property ("in", buf);
      node->add_property ("active", (_active ? "yes" : "no"));
      node->add_property ("follow-overlap", (_follow_overlap ? "yes" : "no"));
      node->add_property ("fixed", (_fixed ? "yes" : "no"));
      snprintf (buf, sizeof(buf), "%" PRIu32, _length);
      node->add_property ("length", buf);
      snprintf (buf, sizeof(buf), "%" PRIu32, (uint32_t) _anchor_point);
      node->add_property ("anchor-point", buf);
      snprintf (buf, sizeof(buf), "%" PRIu32, (uint32_t) _position);
      node->add_property ("position", buf);

      child = node->add_child ("FadeIn");

      for (AutomationList::iterator ii = _fade_in.begin(); ii != _fade_in.end(); ++ii) {
            XMLNode* pnode;

            pnode = new XMLNode ("point");

            snprintf (buf, sizeof (buf), "%" PRIu32, (nframes_t) floor ((*ii)->when));
            pnode->add_property ("x", buf);
            snprintf (buf, sizeof (buf), "%.12g", (*ii)->value);
            pnode->add_property ("y", buf);
            child->add_child_nocopy (*pnode);
      }

      child = node->add_child ("FadeOut");

      for (AutomationList::iterator ii = _fade_out.begin(); ii != _fade_out.end(); ++ii) {
            XMLNode* pnode;

            pnode = new XMLNode ("point");

            snprintf (buf, sizeof (buf), "%" PRIu32, (nframes_t) floor ((*ii)->when));
            pnode->add_property ("x", buf);
            snprintf (buf, sizeof (buf), "%.12g", (*ii)->value);
            pnode->add_property ("y", buf);
            child->add_child_nocopy (*pnode);
      }

      return *node;
}

int
Crossfade::set_state (const XMLNode& node)
{
      XMLNodeConstIterator i;
      XMLNodeList children;
      XMLNode* fi;
      XMLNode* fo;
      const XMLProperty* prop;
      LocaleGuard lg (X_("POSIX"));
      Change what_changed = Change (0);
      nframes_t val;

      if ((prop = node.property ("position")) != 0) {
            sscanf (prop->value().c_str(), "%" PRIu32, &val);
            if (val != _position) {
                  _position = val;
                  what_changed = Change (what_changed | PositionChanged);
            }
      } else {
            warning << _("old-style crossfade information - no position information") << endmsg;
            _position = _in->first_frame();
      }

      if ((prop = node.property ("active")) != 0) {
            bool x = (prop->value() == "yes");
            if (x != _active) {
                  _active = x;
                  what_changed = Change (what_changed | ActiveChanged);
            }
      } else {
            _active = true;
      }

      if ((prop = node.property ("follow-overlap")) != 0) {
            _follow_overlap = (prop->value() == "yes");
      } else {
            _follow_overlap = false;
      }

      if ((prop = node.property ("fixed")) != 0) {
            _fixed = (prop->value() == "yes");
      } else {
            _fixed = false;
      }

      if ((prop = node.property ("anchor-point")) != 0) {
            _anchor_point = AnchorPoint (atoi ((prop->value().c_str())));
      } else {
            _anchor_point = StartOfIn;
      }

      if ((prop = node.property ("length")) != 0) {

            sscanf (prop->value().c_str(), "%" PRIu32, &val);
            if (val != _length) {
                  _length = atol (prop->value().c_str());
                  what_changed = Change (what_changed | LengthChanged);
            }

      } else {
            
            /* XXX this branch is legacy code from before
               the point where we stored xfade lengths.
            */
            
            if ((_length = overlap_length()) == 0) {
                  throw failed_constructor();
            }
      }

      if ((fi = find_named_node (node, "FadeIn")) == 0) {
            return -1;
      }
      
      if ((fo = find_named_node (node, "FadeOut")) == 0) {
            return -1;
      }

      /* fade in */
      
      _fade_in.freeze ();
      _fade_in.clear ();
      
      children = fi->children();
      
      for (i = children.begin(); i != children.end(); ++i) {
            if ((*i)->name() == "point") {
                  nframes_t x;
                  float y;
                  
                  prop = (*i)->property ("x");
                  sscanf (prop->value().c_str(), "%" PRIu32, &x);
                  
                  prop = (*i)->property ("y");
                  sscanf (prop->value().c_str(), "%f", &y);

                  _fade_in.add (x, y);
            }
      }

      _fade_in.thaw ();
      
        /* fade out */
      
      _fade_out.freeze ();
      _fade_out.clear ();

      children = fo->children();
      
      for (i = children.begin(); i != children.end(); ++i) {
            if ((*i)->name() == "point") {
                  nframes_t x;
                  float y;
                  XMLProperty* prop;

                  prop = (*i)->property ("x");
                  sscanf (prop->value().c_str(), "%" PRIu32, &x);

                  prop = (*i)->property ("y");
                  sscanf (prop->value().c_str(), "%f", &y);
                  
                  _fade_out.add (x, y);
            }
      }

      _fade_out.thaw ();

      StateChanged (what_changed); /* EMIT SIGNAL */

      return 0;
}

bool
Crossfade::can_follow_overlap () const
{
      return !_fixed;
}

void
Crossfade::set_follow_overlap (bool yn)
{
      if (yn == _follow_overlap || _fixed) {
            return;
      }

      _follow_overlap = yn;

      if (!yn) {
            set_length (_short_xfade_length);
      } else {
            set_length (_out->first_frame() + _out->length() - _in->first_frame());
      }

      StateChanged (FollowOverlapChanged);
}

nframes_t
Crossfade::set_length (nframes_t len)
{
      nframes_t limit = 0;

      switch (_anchor_point) {
      case StartOfIn:
            limit = _in->length();
            break;

      case EndOfIn:
            limit = _in->length();
            break;

      case EndOfOut:
            limit = _out->length();
            break;
            
      }

      len = min (limit, len);

      double factor = len / (double) _length;

      _in_update = true;
      _fade_out.x_scale (factor);
      _fade_in.x_scale (factor);
      _in_update = false;
      
      _length = len;

      StateChanged (LengthChanged);

      return len;
}

nframes_t
Crossfade::overlap_length () const
{
      if (_fixed) {
            return _length;
      }
      return _out->first_frame() + _out->length() - _in->first_frame();
}

void
Crossfade::set_short_xfade_length (nframes_t n)
{
      _short_xfade_length = n;
}

void
Crossfade::invalidate ()
{
      Invalidated (shared_from_this()); /* EMIT SIGNAL */
}

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