BOOST_FOREACH.
[dcpomatic.git] / src / wx / audio_mapping_view.cc
index fa8732648008d5823288ea5569dc72762655082a..60606b1660b8d1d626d1784bf6661184fea1a9e5 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2019 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2020 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
 #include "audio_gain_dialog.h"
 #include "lib/audio_mapping.h"
 #include "lib/util.h"
+#include "lib/warnings.h"
 #include <dcp/locale_convert.h>
 #include <dcp/types.h>
+DCPOMATIC_DISABLE_WARNINGS
 #include <wx/wx.h>
 #include <wx/renderer.h>
 #include <wx/grid.h>
 #include <wx/graphics.h>
-#include <boost/foreach.hpp>
+DCPOMATIC_ENABLE_WARNINGS
 #include <iostream>
 
 using std::cout;
@@ -44,8 +46,11 @@ using std::max;
 using std::vector;
 using std::pair;
 using std::make_pair;
-using boost::shared_ptr;
+using std::shared_ptr;
 using boost::optional;
+#if BOOST_VERSION >= 106100
+using namespace boost::placeholders;
+#endif
 using dcp::locale_convert;
 
 #define INDICATOR_SIZE 20
@@ -55,30 +60,41 @@ using dcp::locale_convert;
 
 enum {
        ID_off = 1,
-       ID_full = 2,
-       ID_minus6dB = 3,
-       ID_edit = 4
+       ID_minus6dB = 2,
+       ID_0dB = 3,
+       ID_plus3dB = 4,
+       ID_edit = 5
 };
 
-AudioMappingView::AudioMappingView (wxWindow* parent)
+AudioMappingView::AudioMappingView (wxWindow* parent, wxString left_label, wxString from, wxString top_label, wxString to)
        : wxPanel (parent, wxID_ANY)
        , _menu_input (0)
        , _menu_output (1)
+       , _left_label (left_label)
+       , _from (from)
+       , _top_label (top_label)
+       , _to (to)
 {
        _menu = new wxMenu;
        _menu->Append (ID_off, _("Off"));
-       _menu->Append (ID_full, _("Full"));
        _menu->Append (ID_minus6dB, _("-6dB"));
+       _menu->Append (ID_0dB, _("0dB (unchanged)"));
+       _menu->Append (ID_plus3dB, _("+3dB"));
        _menu->Append (ID_edit, _("Edit..."));
 
        _body = new wxPanel (this, wxID_ANY);
        _vertical_scroll = new wxScrollBar (this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxSB_VERTICAL);
        _horizontal_scroll = new wxScrollBar (this, wxID_ANY);
 
+#ifndef __WXOSX__
+       SetDoubleBuffered (true);
+#endif
+
        Bind (wxEVT_SIZE, boost::bind(&AudioMappingView::size, this, _1));
-       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::off, this), ID_off);
-       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::full, this), ID_full);
-       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::minus6dB, this), ID_minus6dB);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 0), ID_off);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(-6)), ID_minus6dB);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 1), ID_0dB);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(3)), ID_plus3dB);
        Bind (wxEVT_MENU, boost::bind(&AudioMappingView::edit, this), ID_edit);
        Bind (wxEVT_MOUSEWHEEL, boost::bind(&AudioMappingView::mouse_wheel, this, _1));
        _body->Bind (wxEVT_PAINT, boost::bind(&AudioMappingView::paint, this));
@@ -148,92 +164,86 @@ AudioMappingView::scroll ()
 }
 
 void
-AudioMappingView::paint_static (wxDC& dc, wxGraphicsContext* gc)
+AudioMappingView::paint_static (wxDC& dc)
 {
-       gc->SetAntialiasMode (wxANTIALIAS_DEFAULT);
        dc.SetFont (wxSWISS_FONT->Bold());
        wxCoord label_width;
        wxCoord label_height;
 
-       /* DCP label at the top */
-
-       dc.GetTextExtent (_("DCP"), &label_width, &label_height);
-       dc.DrawText (_("DCP"), LEFT_WIDTH + (_output_channels.size() * GRID_SPACING - label_width) / 2, (GRID_SPACING - label_height) / 2);
-
-       /* Content label on the left */
+       dc.GetTextExtent (_top_label, &label_width, &label_height);
+       dc.DrawText (_top_label, LEFT_WIDTH + (_output_channels.size() * GRID_SPACING - label_width) / 2, (GRID_SPACING - label_height) / 2);
 
-       dc.GetTextExtent (_("Content"), &label_width, &label_height);
+       dc.GetTextExtent (_left_label, &label_width, &label_height);
        dc.DrawRotatedText (
-               _("Content"),
+               _left_label,
                (GRID_SPACING - label_height) / 2,
                TOP_HEIGHT + (_input_channels.size() * GRID_SPACING + label_width) / 2,
                90
                );
 
        dc.SetFont (*wxSWISS_FONT);
-       gc->SetPen (*wxBLACK_PEN);
 }
 
 void
-AudioMappingView::paint_column_labels (wxDC& dc, wxGraphicsContext* gc)
+AudioMappingView::paint_column_labels (wxDC& dc)
 {
        wxCoord label_width;
        wxCoord label_height;
        int N = 0;
-       BOOST_FOREACH (string i, _output_channels) {
-               dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
-               dc.DrawText (std_to_wx(i), LEFT_WIDTH + GRID_SPACING * N + (GRID_SPACING - label_width) / 2, GRID_SPACING + (GRID_SPACING - label_height) / 2);
+       for (auto const& i: _output_channels) {
+               dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
+               dc.DrawText (std_to_wx(i.name), LEFT_WIDTH + GRID_SPACING * N + (GRID_SPACING - label_width) / 2, GRID_SPACING + (GRID_SPACING - label_height) / 2);
                ++N;
        }
 
-       wxGraphicsPath lines = gc->CreatePath ();
-       lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING);
-       lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING);
-       lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING * 2);
-       lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING * 2);
-       gc->StrokePath (lines);
+       dc.DrawLine(wxPoint(LEFT_WIDTH, GRID_SPACING), wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING));
+       dc.DrawLine(wxPoint(LEFT_WIDTH, GRID_SPACING * 2), wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING * 2));
 }
 
 void
-AudioMappingView::paint_column_lines (wxGraphicsContext* gc)
+AudioMappingView::paint_column_lines (wxDC& dc)
 {
-       wxGraphicsPath lines = gc->CreatePath ();
        for (size_t i = 0; i < _output_channels.size(); ++i) {
-               lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * i, GRID_SPACING);
-               lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
+               dc.DrawLine (
+                       wxPoint(LEFT_WIDTH + GRID_SPACING * i, GRID_SPACING),
+                       wxPoint(LEFT_WIDTH + GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING)
+                       );
        }
-       lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), GRID_SPACING);
-       lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
-       gc->StrokePath (lines);
+
+       dc.DrawLine (
+               wxPoint(LEFT_WIDTH + GRID_SPACING * _output_channels.size(), GRID_SPACING),
+               wxPoint(LEFT_WIDTH + GRID_SPACING * _output_channels.size(), TOP_HEIGHT + _input_channels.size() * GRID_SPACING)
+               );
 }
 
 void
-AudioMappingView::paint_row_labels (wxDC& dc, wxGraphicsContext* gc)
+AudioMappingView::paint_row_labels (wxDC& dc)
 {
        wxCoord label_width;
        wxCoord label_height;
-       wxGraphicsPath lines = gc->CreatePath ();
 
        /* Row channel labels */
 
        int N = 0;
-       BOOST_FOREACH (string i, _input_channels) {
-               dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
-               dc.DrawText (std_to_wx(i), GRID_SPACING * 2 + (GRID_SPACING - label_width) / 2, TOP_HEIGHT + GRID_SPACING * N + (GRID_SPACING - label_height) / 2);
+       for (auto const& i: _input_channels) {
+               dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
+               dc.DrawText (std_to_wx(i.name), GRID_SPACING * 2 + (GRID_SPACING - label_width) / 2, TOP_HEIGHT + GRID_SPACING * N + (GRID_SPACING - label_height) / 2);
                ++N;
        }
 
        /* Vertical lines on the left */
 
        for (int i = 1; i < 3; ++i) {
-               lines.MoveToPoint    (GRID_SPACING * i, TOP_HEIGHT);
-               lines.AddLineToPoint (GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
+               dc.DrawLine (
+                       wxPoint(GRID_SPACING * i, TOP_HEIGHT),
+                       wxPoint(GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING)
+                       );
        }
 
        /* Group labels and lines */
 
        int y = TOP_HEIGHT;
-       BOOST_FOREACH (Group i, _input_groups) {
+       for (auto i: _input_groups) {
                int const height = (i.to - i.from + 1) * GRID_SPACING;
                dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
                if (label_width > height) {
@@ -241,49 +251,40 @@ AudioMappingView::paint_row_labels (wxDC& dc, wxGraphicsContext* gc)
                }
 
                {
+                       wxDCClipper clip (dc, wxRect(GRID_SPACING, y, GRID_SPACING, height));
                        int yp = y;
                        if ((yp - 2 * GRID_SPACING) < dc.GetLogicalOrigin().y) {
                                yp += dc.GetLogicalOrigin().y;
                        }
 
-                       wxCoord old_x, old_y, old_width, old_height;
-                       dc.GetClippingBox (&old_x, &old_y, &old_width, &old_height);
-                       dc.DestroyClippingRegion ();
-                       dc.SetClippingRegion (GRID_SPACING, yp + 4, GRID_SPACING, height - 8);
-
                        dc.DrawRotatedText (
                                std_to_wx(i.name),
                                GRID_SPACING + (GRID_SPACING - label_height) / 2,
                                y + (height + label_width) / 2,
                                90
                                );
-
-                       dc.DestroyClippingRegion ();
-                       dc.SetClippingRegion (old_x, old_y, old_width, old_height);
                }
 
-               lines.MoveToPoint    (GRID_SPACING,     y);
-               lines.AddLineToPoint (GRID_SPACING * 2, y);
+               dc.DrawLine (wxPoint(GRID_SPACING, y), wxPoint(GRID_SPACING * 2, y));
                y += height;
        }
 
-       lines.MoveToPoint    (GRID_SPACING,     y);
-       lines.AddLineToPoint (GRID_SPACING * 2, y);
-
-       gc->StrokePath (lines);
+       dc.DrawLine (wxPoint(GRID_SPACING, y), wxPoint(GRID_SPACING * 2, y));
 }
 
 void
-AudioMappingView::paint_row_lines (wxGraphicsContext* gc)
+AudioMappingView::paint_row_lines (wxDC& dc)
 {
-       wxGraphicsPath lines = gc->CreatePath ();
        for (size_t i = 0; i < _input_channels.size(); ++i) {
-               lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * i);
-               lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * i);
+               dc.DrawLine (
+                       wxPoint(GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * i),
+                       wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * i)
+                       );
        }
-       lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
-       lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
-       gc->StrokePath (lines);
+       dc.DrawLine (
+               wxPoint(GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * _input_channels.size()),
+               wxPoint(LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * _input_channels.size())
+               );
 }
 
 void
@@ -304,14 +305,15 @@ AudioMappingView::paint_indicators (wxDC& dc)
                                        )
                                );
 
-                       float const value_dB = 20 * log10 (_map.get(y, x));
+                       float const value_dB = linear_to_db(_map.get(_input_channels[y].index, _output_channels[x].index));
+                       wxColour const colour = value_dB <= 0 ? wxColour(0, 255, 0) : wxColour(255, 150, 0);
                        int const range = 18;
                        int height = 0;
                        if (value_dB > -range) {
-                               height = INDICATOR_SIZE * (1 + value_dB / range);
+                               height = min(INDICATOR_SIZE, static_cast<int>(INDICATOR_SIZE * (1 + value_dB / range)));
                        }
 
-                       dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(wxColour (0, 255, 0), wxBRUSHSTYLE_SOLID));
+                       dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(colour, wxBRUSHSTYLE_SOLID));
                        dc.DrawRectangle (
                                wxRect(
                                        LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
@@ -324,27 +326,22 @@ AudioMappingView::paint_indicators (wxDC& dc)
 }
 
 static
-void clip (wxDC& dc, wxGraphicsContext* gc, int x, int y, int w, int h)
+void clip (wxDC& dc, int x, int y, int w, int h)
 {
        dc.SetClippingRegion (x, y, w, h);
-       gc->Clip (x, y, w, h);
 }
 
 static
-void translate (wxDC& dc, wxGraphicsContext* gc, int x, int y)
+void translate (wxDC& dc, int x, int y)
 {
-       gc->PushState ();
-       gc->Translate (-x, -y);
        dc.SetLogicalOrigin (x, y);
 }
 
 static
-void restore (wxDC& dc, wxGraphicsContext* gc)
+void restore (wxDC& dc)
 {
        dc.SetLogicalOrigin (0, 0);
-       gc->PopState ();
        dc.DestroyClippingRegion ();
-       gc->ResetClip ();
 }
 
 void
@@ -352,62 +349,85 @@ AudioMappingView::paint ()
 {
        wxPaintDC dc (_body);
 
-       wxGraphicsContext* gc = wxGraphicsContext::Create (dc);
-       if (!gc) {
-               return;
-       }
-
        int const hs = _horizontal_scroll->GetThumbPosition ();
        int const vs = _vertical_scroll->GetThumbPosition ();
 
-       paint_static (dc, gc);
-
-       clip (dc, gc, LEFT_WIDTH, 0, GRID_SPACING * _output_channels.size(), GRID_SPACING * (2 + _input_channels.size()));
-       translate (dc, gc, hs, 0);
-       paint_column_labels (dc, gc);
-       restore (dc, gc);
-
-       clip (dc, gc, 0, TOP_HEIGHT, GRID_SPACING * (3 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
-       translate (dc, gc, 0, vs);
-       paint_row_labels (dc, gc);
-       restore (dc, gc);
-
-       clip (dc, gc, GRID_SPACING * 2, TOP_HEIGHT, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
-       translate (dc, gc, hs, vs);
-       paint_row_lines (gc);
-       restore (dc, gc);
-
-       clip (dc, gc, LEFT_WIDTH, GRID_SPACING, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * (1 + _input_channels.size()));
-       translate (dc, gc, hs, vs);
-       paint_column_lines (gc);
-       restore (dc, gc);
-
-       clip (dc, gc, LEFT_WIDTH, TOP_HEIGHT, GRID_SPACING * _output_channels.size(), GRID_SPACING * _input_channels.size());
-       translate (dc, gc, hs, vs);
+       paint_static (dc);
+
+       clip (
+               dc,
+               LEFT_WIDTH,
+               0,
+               GRID_SPACING * _output_channels.size(),
+               GRID_SPACING * (2 + _input_channels.size())
+            );
+       translate (dc, hs, 0);
+       paint_column_labels (dc);
+       restore (dc);
+
+       clip (
+               dc,
+               0,
+               TOP_HEIGHT,
+               GRID_SPACING * 3,
+               min(int(GRID_SPACING * _input_channels.size()), GetSize().GetHeight() - TOP_HEIGHT)
+            );
+       translate (dc, 0, vs);
+       paint_row_labels (dc);
+       restore (dc);
+
+       clip (
+               dc,
+               GRID_SPACING * 2,
+               TOP_HEIGHT,
+               GRID_SPACING * (1 + _output_channels.size()),
+               min(int(GRID_SPACING * (2 + _input_channels.size())), GetSize().GetHeight() - TOP_HEIGHT)
+            );
+       translate (dc, hs, vs);
+       paint_row_lines (dc);
+       restore (dc);
+
+       clip (
+               dc,
+               LEFT_WIDTH,
+               GRID_SPACING,
+               GRID_SPACING * (1 + _output_channels.size()),
+               min(int(GRID_SPACING * (1 + _input_channels.size())), GetSize().GetHeight() - GRID_SPACING)
+            );
+       translate (dc, hs, vs);
+       paint_column_lines (dc);
+       restore (dc);
+
+       clip (
+               dc,
+               LEFT_WIDTH,
+               TOP_HEIGHT,
+               GRID_SPACING * _output_channels.size(),
+               min(int(GRID_SPACING * _input_channels.size()), GetSize().GetHeight() - TOP_HEIGHT)
+            );
+       translate (dc, hs, vs);
        paint_indicators (dc);
-       restore (dc, gc);
-
-       delete gc;
+       restore (dc);
 }
 
-optional<pair<int, int> >
+optional<pair<NamedChannel, NamedChannel> >
 AudioMappingView::mouse_event_to_channels (wxMouseEvent& ev) const
 {
        int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
        int const y = ev.GetY() + _vertical_scroll->GetThumbPosition();
 
        if (x <= LEFT_WIDTH || y < TOP_HEIGHT) {
-               return optional<pair<int, int> >();
+               return optional<pair<NamedChannel, NamedChannel> >();
        }
 
        int const input = (y - TOP_HEIGHT) / GRID_SPACING;
        int const output = (x - LEFT_WIDTH) / GRID_SPACING;
 
        if (input >= int(_input_channels.size()) || output >= int(_output_channels.size())) {
-               return optional<pair<int, int> >();
+               return optional<pair<NamedChannel, NamedChannel> >();
        }
 
-       return make_pair (input, output);
+       return make_pair (_input_channels[input], _output_channels[output]);
 }
 
 optional<string>
@@ -419,7 +439,7 @@ AudioMappingView::mouse_event_to_input_group_name (wxMouseEvent& ev) const
        }
 
        int y = (ev.GetY() + _vertical_scroll->GetThumbPosition() - (GRID_SPACING * 2)) / GRID_SPACING;
-       BOOST_FOREACH (Group i, _input_groups) {
+       for (auto i: _input_groups) {
                if (i.from <= y && y <= i.to) {
                        return i.name;
                }
@@ -431,15 +451,15 @@ AudioMappingView::mouse_event_to_input_group_name (wxMouseEvent& ev) const
 void
 AudioMappingView::left_down (wxMouseEvent& ev)
 {
-       optional<pair<int, int> > channels = mouse_event_to_channels (ev);
+       optional<pair<NamedChannel, NamedChannel> > channels = mouse_event_to_channels (ev);
        if (!channels) {
                return;
        }
 
-       if (_map.get(channels->first, channels->second) > 0) {
-               _map.set (channels->first, channels->second, 0);
+       if (_map.get(channels->first.index, channels->second.index) > 0) {
+               _map.set (channels->first.index, channels->second.index, 0);
        } else {
-               _map.set (channels->first, channels->second, 1);
+               _map.set (channels->first.index, channels->second.index, 1);
        }
 
        map_values_changed ();
@@ -448,13 +468,13 @@ AudioMappingView::left_down (wxMouseEvent& ev)
 void
 AudioMappingView::right_down (wxMouseEvent& ev)
 {
-       optional<pair<int, int> > channels = mouse_event_to_channels (ev);
+       optional<pair<NamedChannel, NamedChannel> > channels = mouse_event_to_channels (ev);
        if (!channels) {
                return;
        }
 
-       _menu_input = channels->first;
-       _menu_output = channels->second;
+       _menu_input = channels->first.index;
+       _menu_output = channels->second.index;
        PopupMenu (_menu, ev.GetPosition());
 }
 
@@ -479,28 +499,14 @@ void
 AudioMappingView::map_values_changed ()
 {
        Changed (_map);
-       _last_tooltip_channels = optional<pair<int, int> >();
+       _last_tooltip_channels = optional<pair<NamedChannel, NamedChannel> >();
        Refresh ();
 }
 
 void
-AudioMappingView::off ()
+AudioMappingView::set_gain_from_menu (double linear)
 {
-       _map.set (_menu_input, _menu_output, 0);
-       map_values_changed ();
-}
-
-void
-AudioMappingView::full ()
-{
-       _map.set (_menu_input, _menu_output, 1);
-       map_values_changed ();
-}
-
-void
-AudioMappingView::minus6dB ()
-{
-       _map.set (_menu_input, _menu_output, pow (10, -6.0 / 20));
+       _map.set (_menu_input, _menu_output, linear);
        map_values_changed ();
 }
 
@@ -524,78 +530,72 @@ AudioMappingView::set (AudioMapping map)
 }
 
 void
-AudioMappingView::set_input_channels (vector<string> const & names)
+AudioMappingView::set_input_channels (vector<NamedChannel> const& channels)
 {
-       _input_channels = names;
+       _input_channels = channels;
        setup ();
        Refresh ();
 }
 
 void
-AudioMappingView::set_output_channels (vector<string> const & names)
+AudioMappingView::set_output_channels (vector<NamedChannel> const & channels)
 {
-       _output_channels = names;
+       _output_channels = channels;
        setup ();
        Refresh ();
 }
 
+
 wxString
-AudioMappingView::safe_input_channel_name (int n) const
+AudioMappingView::input_channel_name_with_group (NamedChannel const& n) const
 {
-       if (n >= int(_input_channels.size())) {
-               return wxString::Format ("%d", n + 1);
-       }
-
        optional<wxString> group;
-       BOOST_FOREACH (Group i, _input_groups) {
-               if (i.from <= n && n <= i.to) {
+       for (auto i: _input_groups) {
+               if (i.from <= n.index && n.index <= i.to) {
                        group = std_to_wx (i.name);
                }
        }
 
-       if (group) {
-               return wxString::Format ("%s/%s", group->data(), std_to_wx(_input_channels[n]).data());
+       if (group && !group->IsEmpty()) {
+               return wxString::Format ("%s/%s", group->data(), std_to_wx(n.name).data());
        }
 
-       return std_to_wx(_input_channels[n]);
+       return std_to_wx(n.name);
 }
 
-wxString
-AudioMappingView::safe_output_channel_name (int n) const
-{
-       if (n >= int(_output_channels.size())) {
-               return wxString::Format ("%d", n + 1);
-       }
-
-       return std_to_wx(_output_channels[n]);
-}
 
 void
 AudioMappingView::motion (wxMouseEvent& ev)
 {
-       optional<pair<int, int> > channels = mouse_event_to_channels (ev);
+       optional<pair<NamedChannel, NamedChannel> > channels = mouse_event_to_channels (ev);
        if (channels) {
                if (channels != _last_tooltip_channels) {
                        wxString s;
-                       float const gain = _map.get(channels->first, channels->second);
+                       float const gain = _map.get(channels->first.index, channels->second.index);
                        if (gain == 0) {
                                s = wxString::Format (
-                                       _("No audio will be passed from content channel '%s' to DCP channel '%s'."),
-                                       safe_input_channel_name(channels->first),
-                                       safe_output_channel_name(channels->second)
+                                       _("No audio will be passed from %s channel '%s' to %s channel '%s'."),
+                                       _from,
+                                       input_channel_name_with_group(channels->first),
+                                       _to,
+                                       std_to_wx(channels->second.name)
                                        );
                        } else if (gain == 1) {
                                s = wxString::Format (
-                                       _("Audio will be passed from content channel %s to DCP channel %s unaltered."),
-                                       safe_input_channel_name(channels->first),
-                                       safe_output_channel_name(channels->second)
+                                       _("Audio will be passed from %s channel %s to %s channel %s unaltered."),
+                                       _from,
+                                       input_channel_name_with_group(channels->first),
+                                       _to,
+                                       std_to_wx(channels->second.name)
                                        );
                        } else {
-                               float const dB = 20 * log10 (gain);
+                               float const dB = linear_to_db(gain);
                                s = wxString::Format (
-                                       _("Audio will be passed from content channel %s to DCP channel %s with gain %.1fdB."),
-                                       safe_input_channel_name(channels->first),
-                                       safe_output_channel_name(channels->second),
+                                       _("Audio will be passed from %s channel %s to %s channel %s with gain %.1fdB."),
+                                       _from,
+                                       input_channel_name_with_group(channels->first),
+                                       _to,
+                                       std_to_wx(channels->second.name),
                                        dB
                                        );
                        }