View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0006287 | ardour | bugs | public | 2015-04-28 15:00 | 2020-04-19 20:17 |
| Reporter | x42 | Assigned To | drobilla | ||
| Priority | high | Severity | major | Reproducibility | always |
| Status | closed | Resolution | fixed | ||
| Product Version | 4.X git (version in description) | ||||
| Summary | 0006287: session save during playback can produce invalid midi data | ||||
| Description | play some midi-track, press save (or wait for periodic-save to kick in) -> stuck or lost midi events. this is caused by the iterator in MidiSource::midi_read(). MidiSource::session_saved() either directly or indirectly via SMFSource::flush_midi() resets the model and the iterator. If here if there's existing data in the _playback_buf and continue reading various side effects can manifest. I still don't see an easy fix for this. related bug: libs/evoral/src/Sequence.cpp:103 only adds active notes if they're active at time t. but time t is with read-ahead. | ||||
| Tags | No tags attached. | ||||
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some notes on tracking this down. in MidiSource::midi_read premise: even if the model/iterator is *not* invalidated, one should expect that looking up the iterator should yield the same position as the current iterator. Test sequence: 1) T=00 Note-on 1 2) T=10 Note-off 1 3) T=10 Note-on 2 4) T=20 Note-off 2 5) T=20 Note-on 3 6) T=30 Note-off 3 Current iterator is at (4). That is the next event to be read. But _model->begin(conveter( 20 ) ,..) returns iterator (5) Sequence...::operator++() does not see event (4) and hence does not call _active_notes.pop(); -> stuck note The reason why 5 is returned is _note_iter = seq.note_lower_bound(t); std::multiset::lower_bound() is correct but seq.notes() only contains note-on events. tl;dr: https://github.com/Ardour/ardour/blob/master/libs/evoral/src/Sequence.cpp#L350 since the iterator after a _model->begin(...) is always at a note-on ... the _active_notes.pop(); is not called) proposed fix: * change Lock to RWLock (and don't invalidate model on save in the first place) * also make begin correctly position itself at note off, if given (for live edits) |
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Fixed in 4.0-312-g4d2d693 Simple fix since we already had all the required mechanism for the live edit stuff. I am not quite sure about this in all cases, *too many* notes might stick around, but am unable to reproduce the issue any longer after this change. |
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Issue has been closed automatically, by Trigger Close Plugin. Feel free to re-open with additional information if you think the issue is not resolved. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2015-04-28 15:00 | x42 | New Issue | |
| 2015-05-02 03:12 | x42 | Note Added: 0016671 | |
| 2015-05-02 05:01 | x42 | Note Edited: 0016671 | |
| 2015-05-13 00:13 | drobilla | Note Added: 0016684 | |
| 2015-05-13 00:13 | drobilla | Assigned To | => drobilla |
| 2015-05-13 00:13 | drobilla | Status | new => resolved |
| 2015-05-13 00:13 | drobilla | Resolution | open => fixed |
| 2020-04-19 20:17 | system | Note Added: 0023450 | |
| 2020-04-19 20:17 | system | Status | resolved => closed |
