interpolation.cc/.h: Spline-Bugfixes: Crash bug at tempos close to 0, wrong calculati...
[ardour.git] / libs / ardour / audio_playlist.cc
index 290907746b6116666929c721ac534c5b52f93ddc..93bdc333f134413a67faf1ab5e2b91ca3c4beb72 100644 (file)
@@ -15,7 +15,6 @@
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
-    $Id$
 */
 
 #include <algorithm>
 
 #include <sigc++/bind.h>
 
-#include <ardour/types.h>
-#include <ardour/configuration.h>
-#include <ardour/audioplaylist.h>
-#include <ardour/audioregion.h>
-#include <ardour/crossfade.h>
-#include <ardour/crossfade_compare.h>
-#include <ardour/session.h>
+#include "ardour/types.h"
+#include "ardour/configuration.h"
+#include "ardour/audioplaylist.h"
+#include "ardour/audioregion.h"
+#include "ardour/crossfade.h"
+#include "ardour/crossfade_compare.h"
+#include "ardour/session.h"
+#include "pbd/enumwriter.h"
 
 #include "i18n.h"
 
@@ -40,52 +40,47 @@ using namespace std;
 using namespace PBD;
 
 AudioPlaylist::AudioPlaylist (Session& session, const XMLNode& node, bool hidden)
-       : Playlist (session, node, hidden)
+       : Playlist (session, node, DataType::AUDIO, hidden)
 {
+       const XMLProperty* prop = node.property("type");
+       assert(!prop || DataType(prop->value()) == DataType::AUDIO);
+
        in_set_state++;
        set_state (node);
        in_set_state--;
-
-       if (!hidden) {
-               PlaylistCreated (this); /* EMIT SIGNAL */
-       }
 }
 
 AudioPlaylist::AudioPlaylist (Session& session, string name, bool hidden)
-       : Playlist (session, name, hidden)
+       : Playlist (session, name, DataType::AUDIO, hidden)
 {
-       if (!hidden) {
-               PlaylistCreated (this); /* EMIT SIGNAL */
-       }
-
 }
 
-AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, string name, bool hidden)
+AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, string name, bool hidden)
        : Playlist (other, name, hidden)
 {
-       RegionList::const_iterator in_o  = other.regions.begin();
+       RegionList::const_iterator in_o  = other->regions.begin();
        RegionList::iterator in_n = regions.begin();
 
-       while (in_o != other.regions.end()) {
+       while (in_o != other->regions.end()) {
                boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(*in_o);
 
                // We look only for crossfades which begin with the current region, so we don't get doubles
-               for (list<Crossfade *>::const_iterator xfades = other._crossfades.begin(); xfades != other._crossfades.end(); ++xfades) {
+               for (Crossfades::const_iterator xfades = other->_crossfades.begin(); xfades != other->_crossfades.end(); ++xfades) {
                        if ((*xfades)->in() == ar) {
                                // We found one! Now copy it!
 
-                               RegionList::const_iterator out_o = other.regions.begin();
+                               RegionList::const_iterator out_o = other->regions.begin();
                                RegionList::const_iterator out_n = regions.begin();
 
-                               while (out_o != other.regions.end()) {
+                               while (out_o != other->regions.end()) {
                                        
                                        boost::shared_ptr<AudioRegion>ar2 = boost::dynamic_pointer_cast<AudioRegion>(*out_o);
                                        
                                        if ((*xfades)->out() == ar2) {
                                                boost::shared_ptr<AudioRegion>in  = boost::dynamic_pointer_cast<AudioRegion>(*in_n);
                                                boost::shared_ptr<AudioRegion>out = boost::dynamic_pointer_cast<AudioRegion>(*out_n);
-                                               Crossfade *new_fade = new Crossfade (*(*xfades), in, out);
-                                               add_crossfade(*new_fade);
+                                               boost::shared_ptr<Crossfade> new_fade = boost::shared_ptr<Crossfade> (new Crossfade (*xfades, in, out));
+                                               add_crossfade(new_fade);
                                                break;
                                        }
                                        
@@ -99,13 +94,9 @@ AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, string name, bool hidd
                in_o++;
                in_n++;
        }
-
-       if (!hidden) {
-               PlaylistCreated (this); /* EMIT SIGNAL */
-       }
 }
 
-AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, nframes_t start, nframes_t cnt, string name, bool hidden)
+AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, nframes_t start, nframes_t cnt, string name, bool hidden)
        : Playlist (other, start, cnt, name, hidden)
 {
        /* this constructor does NOT notify others (session) */
@@ -113,33 +104,22 @@ AudioPlaylist::AudioPlaylist (const AudioPlaylist& other, nframes_t start, nfram
 
 AudioPlaylist::~AudioPlaylist ()
 {
-       set<Crossfade*> all_xfades;
-
        GoingAway (); /* EMIT SIGNAL */
 
        /* drop connections to signals */
 
        notify_callbacks ();
-
-       for (Crossfades::iterator x = _crossfades.begin(); x != _crossfades.end(); ) {
-               Crossfades::iterator tmp;
-
-               tmp = x;
-               ++tmp;
-
-               delete *x;
-
-               x = tmp;
-       }
+       
+       _crossfades.clear ();
 }
 
 struct RegionSortByLayer {
-    bool operator() (boost::shared_ptr<Region>a, boost::shared_ptr<Region>b) {
+    bool operator() (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
            return a->layer() < b->layer();
     }
 };
 
-nframes_t
+ARDOUR::nframes_t
 AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nframes_t start,
                     nframes_t cnt, unsigned chan_n)
 {
@@ -167,19 +147,27 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
           its OK to block (for short intervals).
        */
 
-       Glib::Mutex::Lock rm (region_lock);
+       Glib::RecMutex::Lock rm (region_lock);
 
        end =  start + cnt - 1;
-
        read_frames = 0;
        skip_frames = 0;
        _read_data_count = 0;
 
+       _read_data_count = 0;
+
+       RegionList* rlist = regions_to_read (start, start+cnt);
+
+       if (rlist->empty()) {
+               delete rlist;
+               return cnt;
+       }
+
        map<uint32_t,vector<boost::shared_ptr<Region> > > relevant_regions;
-       map<uint32_t,vector<Crossfade*> > relevant_xfades;
+       map<uint32_t,vector<boost::shared_ptr<Crossfade> > > relevant_xfades;
        vector<uint32_t> relevant_layers;
 
-       for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
+       for (RegionList::iterator i = rlist->begin(); i != rlist->end(); ++i) {
                if ((*i)->coverage (start, end) != OverlapNone) {
                        relevant_regions[(*i)->layer()].push_back (*i);
                        relevant_layers.push_back ((*i)->layer());
@@ -206,7 +194,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
        for (vector<uint32_t>::iterator l = relevant_layers.begin(); l != relevant_layers.end(); ++l) {
 
                vector<boost::shared_ptr<Region> > r (relevant_regions[*l]);
-               vector<Crossfade*>& x (relevant_xfades[*l]);
+               vector<boost::shared_ptr<Crossfade> >& x (relevant_xfades[*l]);
 
                for (vector<boost::shared_ptr<Region> >::iterator i = r.begin(); i != r.end(); ++i) {
                        boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(*i);
@@ -215,7 +203,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
                        _read_data_count += ar->read_data_count();
                }
                
-               for (vector<Crossfade*>::iterator i = x.begin(); i != x.end(); ++i) {
+               for (vector<boost::shared_ptr<Crossfade> >::iterator i = x.begin(); i != x.end(); ++i) {
                        (*i)->read_at (buf, mixdown_buffer, gain_buffer, start, cnt, chan_n);
 
                        /* don't JACK up _read_data_count, since its the same data as we just
@@ -224,6 +212,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
                }
        }
 
+       delete rlist;
        return ret;
 }
 
@@ -231,7 +220,6 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 void
 AudioPlaylist::remove_dependents (boost::shared_ptr<Region> region)
 {
-       Crossfades::iterator i, tmp;
        boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
 
        if (in_set_state) {
@@ -244,16 +232,13 @@ AudioPlaylist::remove_dependents (boost::shared_ptr<Region> region)
                return;
        }
 
-       for (i = _crossfades.begin(); i != _crossfades.end(); ) {
-               tmp = i;
-               tmp++;
-
+       for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ) {
                
                if ((*i)->involves (r)) {
-                       delete *i;
+                       i = _crossfades.erase (i);
+               } else {
+                       ++i;
                }
-               
-               i = tmp;
        }
 }
 
@@ -283,7 +268,7 @@ void
 AudioPlaylist::refresh_dependents (boost::shared_ptr<Region> r)
 {
        boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(r);
-       set<Crossfade*> updated;
+       set<boost::shared_ptr<Crossfade> > updated;
 
        if (ar == 0) {
                return;
@@ -300,10 +285,16 @@ AudioPlaylist::refresh_dependents (boost::shared_ptr<Region> r)
 
                if ((*x)->involves (ar)) {
 
-                       if (find (updated.begin(), updated.end(), *x) == updated.end()) {
-                               if ((*x)->refresh ()) {
-                                       /* not invalidated by the refresh */
-                                       updated.insert (*x);
+                       pair<set<boost::shared_ptr<Crossfade> >::iterator, bool> const u = updated.insert (*x);
+                       
+                       if (u.second) {
+                               /* x was successfully inserted into the set, so it has not already been updated */
+                               try {
+                                       (*x)->refresh ();
+                               }
+
+                               catch (Crossfade::NoCrossfadeHere& err) {
+                                       // relax, Invalidated during refresh
                                }
                        }
                }
@@ -324,29 +315,29 @@ AudioPlaylist::finalize_split_region (boost::shared_ptr<Region> o, boost::shared
                tmp = x;
                ++tmp;
 
-               Crossfade *fade = 0;
+               boost::shared_ptr<Crossfade> fade;
                
                if ((*x)->_in == orig) {
                        if (! (*x)->covers(right->position())) {
-                               fade = new Crossfade (**x, left, (*x)->_out);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, left, (*x)->_out));
                        } else {
                                // Overlap, the crossfade is copied on the left side of the right region instead
-                               fade = new Crossfade (**x, right, (*x)->_out);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, right, (*x)->_out));
                        }
                }
                
                if ((*x)->_out == orig) {
                        if (! (*x)->covers(right->position())) {
-                               fade = new Crossfade (**x, (*x)->_in, right);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, (*x)->_in, right));
                        } else {
                                // Overlap, the crossfade is copied on the right side of the left region instead
-                               fade = new Crossfade (**x, (*x)->_in, left);
+                               fade = boost::shared_ptr<Crossfade> (new Crossfade (*x, (*x)->_in, left));
                        }
                }
                
                if (fade) {
                        _crossfades.remove (*x);
-                       add_crossfade (*fade);
+                       add_crossfade (fade);
                }
                x = tmp;
        }
@@ -359,7 +350,8 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
        boost::shared_ptr<AudioRegion> region;
        boost::shared_ptr<AudioRegion> top;
        boost::shared_ptr<AudioRegion> bottom;
-       Crossfade*   xfade;
+       boost::shared_ptr<Crossfade>   xfade;
+       RegionList*  touched_regions;
 
        if (in_set_state || in_partition) {
                return;
@@ -375,12 +367,15 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
                refresh_dependents (r);
        }
 
-       if (!Config->get_auto_xfade()) {
+
+       if (!_session.config.get_auto_xfade()) {
                return;
        }
 
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 
+               nframes_t xfade_length;
+
                other = boost::dynamic_pointer_cast<AudioRegion> (*i);
 
                if (other == region) {
@@ -390,6 +385,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
                if (other->muted() || region->muted()) {
                        continue;
                }
+               
 
                if (other->layer() < region->layer()) {
                        top = region;
@@ -399,43 +395,111 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
                        bottom = region;
                }
 
+               if (!top->opaque()) {
+                       continue;
+               }
+
+               OverlapType c = top->coverage (bottom->position(), bottom->last_frame());
+
                try {
+                       switch (c) {
+                       case OverlapNone:
+                               break;
+
+                       case OverlapInternal:
+                                /* {=============== top  =============}
+                                 *     [ ----- bottom  ------- ]
+                                 */
+                               break;
+
+                       case OverlapExternal:
+                               /*     [ -------- top ------- ]
+                                * {=========== bottom =============}
+                                */
                                
-                       if (top->coverage (bottom->position(), bottom->last_frame()) != OverlapNone) {
+                               /* to avoid discontinuities at the region boundaries of an internal
+                                  overlap (this region is completely within another), we create
+                                  two hidden crossfades at each boundary. this is not dependent
+                                  on the auto-xfade option, because we require it as basic
+                                  audio engineering.
+                               */
                                
-                               /* check if the upper region is within the lower region */
-                               
-                               if (top->first_frame() > bottom->first_frame() &&
-                                   top->last_frame() < bottom->last_frame()) {
-                                       
-                                       
-                                       /*     [ -------- top ------- ]
-                                        * {=========== bottom =============}
-                                        */
-                                       
-                                       /* to avoid discontinuities at the region boundaries of an internal
-                                          overlap (this region is completely within another), we create
-                                          two hidden crossfades at each boundary. this is not dependent
-                                          on the auto-xfade option, because we require it as basic
-                                          audio engineering.
+                               xfade_length = min ((nframes_t) 720, top->length());
+
+                               if (top_region_at (top->first_frame()) == top) {
+                                       xfade = boost::shared_ptr<Crossfade> (new Crossfade (top, bottom, xfade_length, top->first_frame(), StartOfIn));
+                                       add_crossfade (xfade);
+                               }
+
+                               if (top_region_at (top->last_frame() - 1) == top) {
+
+                                       /* 
+                                          only add a fade out if there is no region on top of the end of 'top' (which 
+                                          would cover it).
                                        */
                                        
-                                       nframes_t xfade_length = min ((nframes_t) 720, top->length());
-                                       
-                                                           /*  in,      out */
-                                       xfade = new Crossfade (top, bottom, xfade_length, top->first_frame(), StartOfIn);
-                                       add_crossfade (*xfade);
-                                       xfade = new Crossfade (bottom, top, xfade_length, top->last_frame() - xfade_length, EndOfOut);
-                                       add_crossfade (*xfade);
-                                       
+                                       xfade = boost::shared_ptr<Crossfade> (new Crossfade (bottom, top, xfade_length, top->last_frame() - xfade_length, EndOfOut));
+                                       add_crossfade (xfade);
+                               }
+                               break;
+                       case OverlapStart:
+
+                               /*                   { ==== top ============ } 
+                                *   [---- bottom -------------------] 
+                                */
+
+                               if (_session.config.get_xfade_model() == FullCrossfade) {
+                                       touched_regions = regions_touched (top->first_frame(), bottom->last_frame());
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
                                } else {
 
-                                       xfade = new Crossfade (other, region, Config->get_xfade_model(), Config->get_xfades_active());
-                                       add_crossfade (*xfade);
+                                       touched_regions = regions_touched (top->first_frame(), 
+                                                                          top->first_frame() + min ((nframes_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(), 
+                                                                                                    top->length()));
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
                                }
-                       } 
+                               break;
+                       case OverlapEnd:
+
+
+                               /* [---- top ------------------------] 
+                                *                { ==== bottom ============ } 
+                                */ 
+
+                               if (_session.config.get_xfade_model() == FullCrossfade) {
+
+                                       touched_regions = regions_touched (bottom->first_frame(), top->last_frame());
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, 
+                                                                                                    _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
+
+                               } else {
+                                       touched_regions = regions_touched (bottom->first_frame(), 
+                                                                          bottom->first_frame() + min ((nframes_t)_session.config.get_short_xfade_seconds() * _session.frame_rate(), 
+                                                                                                       bottom->length()));
+                                       if (touched_regions->size() <= 2) {
+                                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                                               add_crossfade (xfade);
+                                       }
+                               }
+                               break;
+                       default:
+                               xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, 
+                                                                                    _session.config.get_xfade_model(), _session.config.get_xfades_active()));
+                               add_crossfade (xfade);
+                       }
                }
-               
+
                catch (failed_constructor& err) {
                        continue;
                }
@@ -448,41 +512,43 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 }
 
 void
-AudioPlaylist::add_crossfade (Crossfade& xfade)
+AudioPlaylist::add_crossfade (boost::shared_ptr<Crossfade> xfade)
 {
        Crossfades::iterator ci;
 
        for (ci = _crossfades.begin(); ci != _crossfades.end(); ++ci) {
-               if (*(*ci) == xfade) { // Crossfade::operator==()
+               if (*(*ci) == *xfade) { // Crossfade::operator==()
                        break;
                }
        }
        
        if (ci != _crossfades.end()) {
-               delete &xfade;
+               // it will just go away
        } else {
-               _crossfades.push_back (&xfade);
+               _crossfades.push_back (xfade);
 
-               xfade.Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
-               xfade.StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
+               xfade->Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
+               xfade->StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
 
-               notify_crossfade_added (&xfade);
+               notify_crossfade_added (xfade);
        }
 }
        
-void AudioPlaylist::notify_crossfade_added (Crossfade *x)
+void AudioPlaylist::notify_crossfade_added (boost::shared_ptr<Crossfade> x)
 {
        if (g_atomic_int_get(&block_notifications)) {
                _pending_xfade_adds.insert (_pending_xfade_adds.end(), x);
        } else {
+
                NewCrossfade (x); /* EMIT SIGNAL */
        }
 }
 
 void
-AudioPlaylist::crossfade_invalidated (Crossfade* xfade)
+AudioPlaylist::crossfade_invalidated (boost::shared_ptr<Region> r)
 {
        Crossfades::iterator i;
+       boost::shared_ptr<Crossfade> xfade = boost::dynamic_pointer_cast<Crossfade> (r);
 
        xfade->in()->resume_fade_in ();
        xfade->out()->resume_fade_out ();
@@ -515,7 +581,7 @@ AudioPlaylist::set_state (const XMLNode& node)
                }
 
                try {
-                       Crossfade* xfade = new Crossfade (*((const Playlist *)this), *child);
+                       boost::shared_ptr<Crossfade> xfade = boost::shared_ptr<Crossfade> (new Crossfade (*((const Playlist *)this), *child));
                        _crossfades.push_back (xfade);
                        xfade->Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
                        xfade->StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
@@ -539,19 +605,7 @@ AudioPlaylist::set_state (const XMLNode& node)
 void
 AudioPlaylist::clear (bool with_signals)
 {
-       for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ) {
-
-               Crossfades::iterator tmp;
-               tmp = i;
-               ++tmp;
-
-               delete *i;
-
-               i = tmp;
-       }
-
        _crossfades.clear ();
-       
        Playlist::clear (with_signals);
 }
 
@@ -573,7 +627,7 @@ void
 AudioPlaylist::dump () const
 {
        boost::shared_ptr<Region>r;
-       Crossfade *x;
+       boost::shared_ptr<Crossfade> x;
 
        cerr << "Playlist \"" << _name << "\" " << endl
             << regions.size() << " regions "
@@ -613,7 +667,7 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
        boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
        bool changed = false;
        Crossfades::iterator c, ctmp;
-       set<Crossfade*> unique_xfades;
+       set<boost::shared_ptr<Crossfade> > unique_xfades;
 
        if (r == 0) {
                fatal << _("programming error: non-audio Region passed to remove_overlap in audio playlist")
@@ -622,14 +676,12 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
                return false;
        }
 
-       { 
+       {
                RegionLock rlock (this);
-               RegionList::iterator i;
-               RegionList::iterator tmp;
 
-               for (i = regions.begin(); i != regions.end(); ) {
+               for (RegionList::iterator i = regions.begin(); i != regions.end(); ) {
                        
-                       tmp = i;
+                       RegionList::iterator tmp = i;
                        ++tmp;
                        
                        if ((*i) == region) {
@@ -639,6 +691,21 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
                        
                        i = tmp;
                }
+
+               for (set<boost::shared_ptr<Region> >::iterator x = all_regions.begin(); x != all_regions.end(); ) {
+
+                       set<boost::shared_ptr<Region> >::iterator xtmp = x;
+                       ++xtmp;
+                       
+                       if ((*x) == region) {
+                               all_regions.erase (x);
+                               changed = true;
+                       }
+                       
+                       x = xtmp;
+               }
+
+               region->set_playlist (boost::shared_ptr<Playlist>());
        }
 
        for (c = _crossfades.begin(); c != _crossfades.end(); ) {
@@ -653,10 +720,6 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
                c = ctmp;
        }
 
-       for (set<Crossfade*>::iterator c = unique_xfades.begin(); c != unique_xfades.end(); ++c) {
-               delete *c;
-       }
-
        if (changed) {
                /* overload this, it normally means "removed", not destroyed */
                notify_region_removed (region);
@@ -666,7 +729,7 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 }
 
 void
-AudioPlaylist::crossfade_changed (Change ignored)
+AudioPlaylist::crossfade_changed (Change)
 {
        if (in_flush || in_set_state) {
                return;
@@ -723,3 +786,11 @@ AudioPlaylist::crossfades_at (nframes_t frame, Crossfades& clist)
        }
 }
 
+void
+AudioPlaylist::foreach_crossfade (sigc::slot<void, boost::shared_ptr<Crossfade> > s)
+{
+       RegionLock rl (this, false);
+       for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ++i) {
+               s (*i);
+       }
+}