add explicit inverse fade in/out curves for use when doing constant power xfading

git-svn-id: svn://localhost/ardour2/branches/3.0@12123 d708f5d6-7413-0410-9779-e7cbd77b26cf

diff --git a/libs/ardour/ardour/audioregion.h b/libs/ardour/ardour/audioregion.h
index 87d515d39975323eb9188630c2bf69e10ca87390..1a8b2c9d79b903ac7d748fb0e1d4ac97d90344ea 100644 (file)
--- a/libs/ardour/ardour/audioregion.h
+++ b/libs/ardour/ardour/audioregion.h
@@ -233,7 +233,9 @@ class AudioRegion : public Region
        Automatable _automatable;
 
        boost::shared_ptr<AutomationList> _fade_in;
+       boost::shared_ptr<AutomationList> _inverse_fade_in;
        boost::shared_ptr<AutomationList> _fade_out;
+       boost::shared_ptr<AutomationList> _inverse_fade_out;
        boost::shared_ptr<AutomationList> _envelope;
        uint32_t                          _fade_in_suspended;
        uint32_t                          _fade_out_suspended;

diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 79ee58b410078f9b8675bc178c56b669743ed852..590572644a9ce7fabbd95e9c4ec0c8264a87da29 100644 (file)
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -551,11 +551,34 @@ AudioRegion::_read_at (const SourceList& srcs, framecnt_t limit,
         */
 
        if (fade_in_limit != 0) {
-               _fade_in->curve().get_vector (internal_offset, internal_offset + fade_in_limit, gain_buffer, fade_in_limit);
+               if (_inverse_fade_in) {
 
-               /* Fade the current data out */
-               for (framecnt_t n = 0; n < fade_in_limit; ++n) {
-                       buf[n] *= 1 - gain_buffer[n];
+                       /* explicit inverse fade in curve (e.g. for constant
+                        * power), so we have to fetch it.
+                        */
+
+                       _inverse_fade_in->curve().get_vector (internal_offset, internal_offset + fade_in_limit, gain_buffer, fade_in_limit);
+
+                       /* Fade the data from lower layers out */
+                       for (framecnt_t n = 0; n < fade_in_limit; ++n) {
+                               buf[n] *= gain_buffer[n];
+                       }
+
+                       /* refill gain buffer with the fade in */
+
+                       _fade_in->curve().get_vector (internal_offset, internal_offset + fade_in_limit, gain_buffer, fade_in_limit);
+
+               } else {
+
+                       /* no explicit inverse fade in, so just use (1 - fade
+                        * in) for the fade out of lower layers
+                        */
+
+                       _fade_in->curve().get_vector (internal_offset, internal_offset + fade_in_limit, gain_buffer, fade_in_limit);
+
+                       for (framecnt_t n = 0; n < fade_in_limit; ++n) {
+                               buf[n] *= 1 - gain_buffer[n];
+                       }
                }
 
                /* Mix our newly-read data in, with the fade */
@@ -565,15 +588,36 @@ AudioRegion::_read_at (const SourceList& srcs, framecnt_t limit,
        }
 
        if (fade_out_limit != 0) {
+
                framecnt_t const curve_offset = fade_interval_start - (limit - _fade_out->back()->when);
-               _fade_out->curve().get_vector (curve_offset, curve_offset + fade_out_limit, gain_buffer, fade_out_limit);
 
-               /* Fade the current data in */
-               for (framecnt_t n = 0, m = fade_out_offset; n < fade_out_limit; ++n, ++m) {
-                       buf[m] *= 1 - gain_buffer[n];
+               if (_inverse_fade_out) {
+
+                       _inverse_fade_out->curve().get_vector (curve_offset, curve_offset + fade_out_limit, gain_buffer, fade_out_limit);
+
+                       /* Fade the data from lower levels out */
+                       for (framecnt_t n = 0, m = fade_out_offset; n < fade_out_limit; ++n, ++m) {
+                               buf[m] *= gain_buffer[n];
+                       }
+
+                       /* fetch the actual fade out */
+
+                       _fade_out->curve().get_vector (curve_offset, curve_offset + fade_out_limit, gain_buffer, fade_out_limit);
+
+               } else {
+                       
+                       /* no explicit inverse fade out, so just use (1 - fade
+                        * out) for the fade in of lower layers
+                        */
+
+                       _fade_out->curve().get_vector (curve_offset, curve_offset + fade_out_limit, gain_buffer, fade_out_limit);
+               
+                       for (framecnt_t n = 0, m = fade_out_offset; n < fade_out_limit; ++n, ++m) {
+                               buf[m] *= 1 - gain_buffer[n];
+                       }
                }
 
-               /* Mix our newly-read data in, with the fade */
+               /* Mix our newly-read data out, with the fade */
                for (framecnt_t n = 0, m = fade_out_offset; n < fade_out_limit; ++n, ++m) {
                        buf[m] += mixdown_buffer[m] * gain_buffer[n];
                }
@@ -788,6 +832,7 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
        case FadeLinear:
                _fade_in->fast_simple_add (0.0, 0.0);
                _fade_in->fast_simple_add (len, 1.0);
+               _inverse_fade_in.reset ();
                break;
 
        case FadeFast:
@@ -798,6 +843,7 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add (len * 0.9447, 0.483333);
                _fade_in->fast_simple_add (len * 0.976959, 0.697222);
                _fade_in->fast_simple_add (len, 1);
+               _inverse_fade_in.reset ();
                break;
 
        case FadeSlow:
@@ -809,6 +855,7 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add (len * 0.481567, 0.980556);
                _fade_in->fast_simple_add (len * 0.767281, 1);
                _fade_in->fast_simple_add (len, 1);
+               _inverse_fade_in.reset ();
                break;
 
        case FadeLogA:
@@ -819,6 +866,7 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add (len * 0.652074, 0.972222);
                _fade_in->fast_simple_add (len * 0.771889, 0.988889);
                _fade_in->fast_simple_add (len, 1);
+               _inverse_fade_in.reset ();
                break;
 
        case FadeLogB:
@@ -829,6 +877,7 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add (len * 0.847926, 0.558333);
                _fade_in->fast_simple_add (len * 0.919355, 0.730556);
                _fade_in->fast_simple_add (len, 1);
+               _inverse_fade_in.reset ();
                break;
 
        case FadeConstantPowerMinus3dB:
@@ -839,6 +888,22 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add ((len * 0.666667), 0.851507);
                _fade_in->fast_simple_add ((len * 0.833333), 0.948859);
                _fade_in->fast_simple_add (len, 1.0);
+
+               /* setup complementary fade out for lower layers */
+
+               if (!_inverse_fade_in) {
+                       _inverse_fade_in.reset (new AutomationList (Evoral::Parameter (FadeInAutomation)));
+               }
+
+               _inverse_fade_in->clear ();
+               _inverse_fade_in->fast_simple_add (0.0, 1.0);
+               _inverse_fade_in->fast_simple_add ((len * 0.166667), 0.948859);
+               _inverse_fade_in->fast_simple_add ((len * 0.333333), 0.851507);
+               _inverse_fade_in->fast_simple_add ((len * 0.500000), 0.707946);
+               _inverse_fade_in->fast_simple_add ((len * 0.666667), 0.518174);
+               _inverse_fade_in->fast_simple_add ((len * 0.833333), 0.282192);
+               _inverse_fade_in->fast_simple_add (len, 0.0);
+
                break;
                
        case FadeConstantPowerMinus6dB:
@@ -849,6 +914,22 @@ AudioRegion::set_fade_in (FadeShape shape, framecnt_t len)
                _fade_in->fast_simple_add ((len * 0.666667), 0.666186);
                _fade_in->fast_simple_add ((len * 0.833333), 0.833033);
                _fade_in->fast_simple_add (len, 1.0);
+
+               /* setup complementary fade out for lower layers */
+
+               if (!_inverse_fade_in) {
+                       _inverse_fade_in.reset (new AutomationList (Evoral::Parameter (FadeInAutomation)));
+               }
+
+               _inverse_fade_in->clear ();
+               _inverse_fade_in->fast_simple_add (0.0, 1.0);
+               _inverse_fade_in->fast_simple_add ((len * 0.166667), 0.833033);
+               _inverse_fade_in->fast_simple_add ((len * 0.333333), 0.666186);
+               _inverse_fade_in->fast_simple_add ((len * 0.500000), 0.499459);
+               _inverse_fade_in->fast_simple_add ((len * 0.666667), 0.332853);
+               _inverse_fade_in->fast_simple_add ((len * 0.833333), 0.166366);
+               _inverse_fade_in->fast_simple_add (len, 0.0);
+
                break;
        }
 
@@ -881,6 +962,7 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
                _fade_out->fast_simple_add (len * 0.370968, 0.0861111);
                _fade_out->fast_simple_add (len * 0.610599, 0.0333333);
                _fade_out->fast_simple_add (1.0, 0.0);
+               _inverse_fade_out.reset ();
                break;
 
        case FadeLogA:
@@ -891,6 +973,7 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
                _fade_out->fast_simple_add (len * 0.753456, 0.658333);
                _fade_out->fast_simple_add (len * 0.9262673, 0.308333);
                _fade_out->fast_simple_add (len, 0.0);
+               _inverse_fade_out.reset ();
                break;
 
        case FadeSlow:
@@ -901,6 +984,7 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
                _fade_out->fast_simple_add (len * 0.918981, 0.68595);
                _fade_out->fast_simple_add (len * 0.976852, 0.22865);
                _fade_out->fast_simple_add (len, 0.0);
+               _inverse_fade_out.reset ();
                break;
 
        case FadeLogB:
@@ -910,11 +994,13 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
                _fade_out->fast_simple_add (len * 0.470046, 0.152778);
                _fade_out->fast_simple_add (len * 0.695853, 0.0694444);
                _fade_out->fast_simple_add (len, 0.0);
+               _inverse_fade_out.reset ();     
                break;
 
        case FadeLinear:
                _fade_out->fast_simple_add (0.0, 1.0);
                _fade_out->fast_simple_add (len, 0.0);
+               _inverse_fade_out.reset ();
                break;
 
        case FadeConstantPowerMinus3dB:
@@ -925,6 +1011,22 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
                _fade_out->fast_simple_add ((len * 0.666667), 0.518174);
                _fade_out->fast_simple_add ((len * 0.833333), 0.282192);
                _fade_out->fast_simple_add (len, 0.0);
+
+               /* setup complementary fade in for lower layers */
+
+               if (!_inverse_fade_out) {
+                       _inverse_fade_out.reset (new AutomationList (Evoral::Parameter (FadeInAutomation)));
+               }
+
+               _inverse_fade_out->clear ();
+               _inverse_fade_out->fast_simple_add (0.0, 0.0);
+               _inverse_fade_out->fast_simple_add ((len * 0.166667), 0.166366);
+               _inverse_fade_out->fast_simple_add ((len * 0.333333), 0.332853);
+               _inverse_fade_out->fast_simple_add ((len * 0.500000), 0.499459);
+               _inverse_fade_out->fast_simple_add ((len * 0.666667), 0.666186);
+               _inverse_fade_out->fast_simple_add ((len * 0.833333), 0.833033);
+               _inverse_fade_out->fast_simple_add (len, 1.0);
+
                break;
 
        case FadeConstantPowerMinus6dB:
@@ -935,6 +1037,22 @@ AudioRegion::set_fade_out (FadeShape shape, framecnt_t len)
                _fade_out->fast_simple_add ((len * 0.666667), 0.332853);
                _fade_out->fast_simple_add ((len * 0.833333), 0.166366);
                _fade_out->fast_simple_add (len, 0.0);
+
+               /* setup complementary fade in for lower layers */
+
+               if (!_inverse_fade_out) {
+                       _inverse_fade_out.reset (new AutomationList (Evoral::Parameter (FadeInAutomation)));
+               }
+
+               _inverse_fade_out->clear ();
+               _inverse_fade_out->fast_simple_add (0.0, 0.0);
+               _inverse_fade_out->fast_simple_add ((len * 0.166667), 0.166366);
+               _inverse_fade_out->fast_simple_add ((len * 0.333333), 0.332853);
+               _inverse_fade_out->fast_simple_add ((len * 0.500000), 0.499459);
+               _inverse_fade_out->fast_simple_add ((len * 0.666667), 0.666186);
+               _inverse_fade_out->fast_simple_add ((len * 0.833333), 0.833033);
+               _inverse_fade_out->fast_simple_add (len, 1.0);
+
                break;
        }