Potential fix for lost VST MIDI events

[ardour.git] / libs / ardour / vst_plugin.cc

diff --git a/libs/ardour/vst_plugin.cc b/libs/ardour/vst_plugin.cc
index e150f7bc364b9637ce0bf2652cb8b07cab1748d8..6a29d9d5dfb97ad8e550e24c9f634f92a702136d 100644 (file)
--- a/libs/ardour/vst_plugin.cc
+++ b/libs/ardour/vst_plugin.cc
@@ -139,6 +139,31 @@ VSTPlugin::set_block_size (pframes_t nframes)
        return 0;
 }
 
+bool
+VSTPlugin::requires_fixed_sized_buffers () const
+{
+       /* This controls if Ardour will split the plugin's run()
+        * on automation events in order to pass sample-accurate automation
+        * via standard control-ports.
+        *
+        * When returning true Ardour will *not* sub-divide the process-cycle.
+        * Automation events that happen between cycle-start and cycle-end will be
+        * ignored (ctrl values are interpolated to cycle-start).
+        *
+        * Note: This does not guarantee a fixed block-size.
+        * e.g The process cycle may be split when looping, also
+        * the period-size may change any time: see set_block_size()
+        */
+       if (get_info()->n_inputs.n_midi() > 0) {
+               /* we don't yet implement midi buffer offsets (for split cycles).
+                * Also session_vst callbacls uses _session.transport_sample() directly
+                * (for BBT) which is not offset for plugin cycle split.
+                */
+               return true;
+       }
+       return false;
+}
+
 float
 VSTPlugin::default_value (uint32_t which)
 {
@@ -709,6 +734,7 @@ VSTPlugin::connect_and_run (BufferSet& bufs,
                VstEvents* v = 0;
                bool valid = false;
                const uint32_t buf_index_in = in_map.get(DataType::MIDI, 0, &valid);
+               /* TODO: apply offset to MIDI buffer and trim at nframes */
                if (valid) {
                        v = bufs.get_vst_midi (buf_index_in);
                }
@@ -716,7 +742,8 @@ VSTPlugin::connect_and_run (BufferSet& bufs,
                const uint32_t buf_index_out = out_map.get(DataType::MIDI, 0, &valid);
                if (valid) {
                        _midi_out_buf = &bufs.get_midi(buf_index_out);
-                       _midi_out_buf->silence(0, 0);
+                       /* TODO: apply offset to MIDI buffer and trim at nframes */
+                       _midi_out_buf->silence(nframes, offset);
                } else {
                        _midi_out_buf = 0;
                }