Warn if doing a gain calculation might cause clipping.

diff --git a/src/wx/audio_panel.cc b/src/wx/audio_panel.cc
index 5523d25393088196d88655581121b43f740c6522..d6137ad9f1b122e716d889199e6d100bd3e6564a 100644 (file)
--- a/src/wx/audio_panel.cc
+++ b/src/wx/audio_panel.cc
@@ -258,13 +258,22 @@ AudioPanel::gain_calculate_button_clicked ()
                return;
        }
 
-       _gain->wrapped()->SetValue(_gain->wrapped()->GetValue() + *c);
+       optional<float> old_peak_dB = peak ();
+       double old_value = _gain->wrapped()->GetValue();
+       _gain->wrapped()->SetValue(old_value + *c);
 
        /* This appears to be necessary, as the change is not signalled,
           I think.
        */
        _gain->view_changed ();
 
+       optional<float> peak_dB = peak ();
+       if (old_peak_dB && *old_peak_dB < -0.5 && peak_dB && *peak_dB > -0.5) {
+               error_dialog (this, _("It is not possible to adjust the content's gain for this fader change as it would cause the DCP's audio to clip.  The gain has not been changed."));
+               _gain->wrapped()->SetValue (old_value);
+               _gain->view_changed ();
+       }
+
        d->Destroy ();
 }
 
@@ -360,22 +369,40 @@ AudioPanel::show_clicked ()
        _audio_dialog->Show ();
 }
 
-void
-AudioPanel::setup_peak ()
+/** @return If there is one selected piece of audio content, return its peak value in dB (if known) */
+optional<float>
+AudioPanel::peak () const
 {
-       ContentList sel = _parent->selected_audio ();
        optional<float> peak_dB;
 
-       if (sel.size() != 1) {
-               _peak->SetLabel (wxT (""));
-       } else {
+       ContentList sel = _parent->selected_audio ();
+       if (sel.size() == 1) {
                shared_ptr<Playlist> playlist (new Playlist);
                playlist->add (_parent->film(), sel.front());
                try {
-                       shared_ptr<AudioAnalysis> analysis (new AudioAnalysis (_parent->film()->audio_analysis_path (playlist)));
-                       peak_dB = 20 * log10 (analysis->overall_sample_peak().first.peak) + analysis->gain_correction (playlist);
-                       _peak->SetLabel (wxString::Format (_("Peak: %.2fdB"), *peak_dB));
+                       shared_ptr<AudioAnalysis> analysis (new AudioAnalysis(_parent->film()->audio_analysis_path(playlist)));
+                       peak_dB = 20 * log10 (analysis->overall_sample_peak().first.peak) + analysis->gain_correction(playlist);
                } catch (...) {
+
+               }
+       }
+
+       return peak_dB;
+}
+
+void
+AudioPanel::setup_peak ()
+{
+       ContentList sel = _parent->selected_audio ();
+
+       optional<float> peak_dB = peak ();
+       if (sel.size() != 1) {
+               _peak->SetLabel (wxT(""));
+       } else {
+               peak_dB = peak ();
+               if (peak_dB) {
+                       _peak->SetLabel (wxString::Format(_("Peak: %.2fdB"), *peak_dB));
+               } else {
                        _peak->SetLabel (_("Peak: unknown"));
                }
        }

diff --git a/src/wx/audio_panel.h b/src/wx/audio_panel.h
index 09aae055246156269630b1130ef81966c3f3e5d0..f7161f10a8af39c9fb5729d7668f6b5f6c50d957 100644 (file)
--- a/src/wx/audio_panel.h
+++ b/src/wx/audio_panel.h
@@ -50,6 +50,7 @@ private:
        void setup_sensitivity ();
        void reference_clicked ();
        void add_to_grid ();
+       boost::optional<float> peak () const;
 
        wxCheckBox* _reference;
        wxStaticText* _reference_note;