Make MIDI disk-reader a bit less buggy :)

* use start/end frame
* differentiate nframes and disk_samples_to_consume
* add global Port::port_offset () when writing data.
* add a note about b0rked vari-speed ..

diff --git a/libs/ardour/ardour/disk_reader.h b/libs/ardour/ardour/disk_reader.h
index be336fffadfab4fd8fe6303c30f9b094e2a8abda..04e4ccb3a149006aff4220fa6de0cf2c8b77ed58 100644 (file)
--- a/libs/ardour/ardour/disk_reader.h
+++ b/libs/ardour/ardour/disk_reader.h
@@ -149,7 +149,7 @@ class LIBARDOUR_API DiskReader : public DiskIOProcessor
 
        sampleoffset_t calculate_playback_distance (pframes_t);
 
-       void get_midi_playback (MidiBuffer& dst, samplecnt_t nframes, MonitorState, BufferSet&, double speed, samplecnt_t distance);
+       void get_midi_playback (MidiBuffer& dst, samplepos_t start_sample, samplepos_t end_sample, MonitorState, BufferSet&, double speed, samplecnt_t distance);
 };
 
 } // namespace

diff --git a/libs/ardour/disk_reader.cc b/libs/ardour/disk_reader.cc
index 6cb6bfcbd900b71c00ee8a8ff09fb005d425bbef..f610ce495055a4ed14437b726cc93ce884ec8fa7 100644 (file)
--- a/libs/ardour/disk_reader.cc
+++ b/libs/ardour/disk_reader.cc
@@ -416,7 +416,7 @@ DiskReader::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
                }
 
                if ((ms & MonitoringDisk) && !still_locating) {
-                       get_midi_playback (*dst, disk_samples_to_consume, ms, scratch_bufs, speed, disk_samples_to_consume);
+                       get_midi_playback (*dst, start_sample, end_sample, ms, scratch_bufs, speed, disk_samples_to_consume);
                }
        }
 
@@ -1243,25 +1243,26 @@ DiskReader::resolve_tracker (Evoral::EventSink<samplepos_t>& buffer, samplepos_t
  *  so that an event at playback_sample has time = 0
  */
 void
-DiskReader::get_midi_playback (MidiBuffer& dst, samplecnt_t nframes, MonitorState ms, BufferSet& scratch_bufs, double speed, samplecnt_t disk_samples_to_consume)
+DiskReader::get_midi_playback (MidiBuffer& dst, samplepos_t start_sample, samplepos_t end_sample, MonitorState ms, BufferSet& scratch_bufs, double speed, samplecnt_t disk_samples_to_consume)
 {
        MidiBuffer* target;
+       samplepos_t nframes = end_sample - start_sample;
 
        if ((ms & MonitoringInput) == 0) {
-               dst.clear();
+               /* Route::process_output_buffers() clears the buffer as-needed */
                target = &dst;
        } else {
                target = &scratch_bufs.get_midi (0);
        }
 
        if (ms & MonitoringDisk) {
-               /* no disk data needed */
+               /* disk data needed */
 
                Location* loc = loop_location;
 
                DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose (
                                     "%1 MDS pre-read read %8 offset = %9 @ %4..%5 from %2 write to %3, LOOPED ? %6 .. %7\n", _name,
-                                    _midi_buf->get_read_ptr(), _midi_buf->get_write_ptr(), playback_sample, playback_sample + nframes,
+                                    _midi_buf->get_read_ptr(), _midi_buf->get_write_ptr(), start_sample, end_sample,
                                     (loc ? loc->start() : -1), (loc ? loc->end() : -1), nframes, Port::port_offset()));
 
                //cerr << "======== PRE ========\n";
@@ -1274,7 +1275,7 @@ DiskReader::get_midi_playback (MidiBuffer& dst, samplecnt_t nframes, MonitorStat
                        samplepos_t effective_start;
 
                        Evoral::Range<samplepos_t> loop_range (loc->start(), loc->end() - 1);
-                       effective_start = loop_range.squish (playback_sample);
+                       effective_start = loop_range.squish (start_sample);
 
                        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("looped, effective start adjusted to %1\n", effective_start));
 
@@ -1321,12 +1322,12 @@ DiskReader::get_midi_playback (MidiBuffer& dst, samplecnt_t nframes, MonitorStat
                                events_read = _midi_buf->read (*target, effective_start, effective_start + nframes);
                        }
                } else {
-                       const size_t n_skipped = _midi_buf->skip_to (playback_sample);
+                       const size_t n_skipped = _midi_buf->skip_to (start_sample);
                        if (n_skipped > 0) {
                                warning << string_compose(_("MidiDiskstream %1: skipped %2 events, possible underflow"), id(), n_skipped) << endmsg;
                        }
-                       DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("playback buffer read, from %1 to %2 (%3)", playback_sample, playback_sample + nframes, nframes));
-                       events_read = _midi_buf->read (*target, playback_sample, playback_sample + nframes);
+                       DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("playback buffer read, from %1 to %2 (%3)", start_sample, end_sample, nframes));
+                       events_read = _midi_buf->read (*target, start_sample, end_sample, Port::port_offset ());
                }
 
                DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose (
@@ -1339,10 +1340,12 @@ DiskReader::get_midi_playback (MidiBuffer& dst, samplecnt_t nframes, MonitorStat
        g_atomic_int_add (&_samples_read_from_ringbuffer, nframes);
 
        /* vari-speed */
-
        if (speed != 0.0 && fabsf (speed) != 1.0f) {
                for (MidiBuffer::iterator i = target->begin(); i != target->end(); ++i) {
                        MidiBuffer::TimeType *tme = i.timeptr();
+                       // XXX need to subtract port offsets before scaling
+                       // also we must only scale events read from disk
+                       // and not existing input data in the buffer.
                        *tme = (*tme) * nframes / disk_samples_to_consume;
                }
        }