Properly initialize midi-meters

Midi meters are using linear 0..1 range, (not decibels, no log-scale
falloff).

If a track is deactivated, run() is never called. the queued reset never
executed and the meter remained at the initialization default -inf
(visually it looked like a pegged meter).

diff --git a/libs/ardour/meter.cc b/libs/ardour/meter.cc
index da97041657f4380171fe49cc22540ef571a288eb..945dec7f73e0941684280fcf34d214ddb65d4f93 100644 (file)
--- a/libs/ardour/meter.cc
+++ b/libs/ardour/meter.cc
@@ -103,6 +103,9 @@ PeakMeter::run (BufferSet& bufs, samplepos_t /*start_sample*/, samplepos_t /*end
        // Meter MIDI in to the first n_midi peaks
        for (uint32_t i = 0; i < n_midi; ++i, ++n) {
                float val = 0.0f;
+               if (do_reset_dpm) {
+                       _peak_power[n] = 0;
+               }
                const MidiBuffer& buf (bufs.get_midi(i));
 
                for (MidiBuffer::const_iterator e = buf.begin(); e != buf.end(); ++e) {
@@ -203,6 +206,10 @@ PeakMeter::reset ()
                        _peak_power[i] = -std::numeric_limits<float>::infinity();
                        _peak_buffer[i] = 0;
                }
+               const uint32_t n_midi = min (current_meters.n_midi(), (uint32_t)_peak_power.size());
+               for (size_t i = 0; i < n_midi; ++i) {
+                       _peak_power[i] = 0;
+               }
        }
 
        // these are handled async just fine.
@@ -285,7 +292,11 @@ PeakMeter::set_max_channels (const ChanCount& chn)
 
        while (_peak_power.size() < limit) {
                _peak_buffer.push_back(0);
-               _peak_power.push_back(-std::numeric_limits<float>::infinity());
+               if (_peak_power.size() < current_meters.n_midi()) {
+                       _peak_power.push_back(0);
+               } else {
+                       _peak_power.push_back(-std::numeric_limits<float>::infinity());
+               }
                _max_peak_signal.push_back(0);
        }