Some midi messages are not recorded on a MIDI track?

Installation & Configuration Mac OS X
#1

Hello,
i am using Ardour 8 on MacOs.
I have created a MIDI track. connected on input to a virtual IAC Bus 1 et on output on a virtual IAC Bus 2:
Virtual IAC Bus 1 → Ardour MIDI track → Virtual IAC Bus 2
On input i send the List 1 of MIDI messages below. Then they appear on output as expected.
The problem i have is when i record the MIDI track and play the track after. Then on output i observe the List 2 of MIDI messages below where some messages are missing.
To help the reading, i put below (:number) on the right column related to the missing messages, where the two lists are different.

I tried many times, and this problem always appeared. How to understand it or avoid it?
Thanks,
Frédéric.

List 1 (obtained by Ardour Midi Tracer) of MIDI messages on input virtual IAC Bus 1:

803237188      Controller chn  1 0e 03
   803237316      Controller chn  1 15 00
   803237316      Controller chn  1 16 00
   803237316      Controller chn  1 17 00
   803237316      Controller chn  1 18 00
   803237316      Controller chn  1 35 00
   803237316      Controller chn  1 36 00
   803237316      Controller chn  1 37 00
   803237316      Controller chn  1 38 00
   803237316      Controller chn  1 0f 00
   803237316      Controller chn  1 23 3c
   803237316      Controller chn  1 29 01
   803237316      Controller chn  1 02 39
   803237316      Pitch Bend chn  1 00 40
   803237444          NoteOn chn  1 3c 39
   803273798      Controller chn  2 0e 03
   803273924      Controller chn  2 15 7f
   803273924      Controller chn  2 16 01
   803273924      Controller chn  2 17 00
   803273924      Controller chn  2 18 00
   803273924      Controller chn  2 35 00
   803273924      Controller chn  2 36 00
   803273924      Controller chn  2 37 00
   803273924      Controller chn  2 38 00
   803273924      Controller chn  2 0f 00
   803273924      Controller chn  2 23 43
   803273924      Controller chn  2 29 01
   803273924      Controller chn  2 02 2f
   803273924      Pitch Bend chn  2 50 40
   803274051          NoteOn chn  2 43 2f
   803313860      Controller chn  2 0e 03           :1
   803313987      Controller chn  2 0f 00           :2
   803313987      Controller chn  2 23 43
   803313987      Controller chn  2 02 00
   803314115         NoteOff chn  2 43 7f
   803334214      Controller chn  2 0e 03          :3
   803334340      Controller chn  2 15 01
   803334340      Controller chn  2 16 01
   803334340      Controller chn  2 17 7f
   803334340      Controller chn  2 18 00           :4
   803334340      Controller chn  2 35 00           :5
   803334340      Controller chn  2 36 00           :6
   803334340      Controller chn  2 37 00           :7
   803334340      Controller chn  2 38 00           :8
   803334340      Controller chn  2 0f 00            :9
   803334340      Controller chn  2 23 3f
   803334340      Controller chn  2 29 01           :10
   803334340      Controller chn  2 02 2f               
   803334340      Pitch Bend chn  2 00 45
   803334468          NoteOn chn  2 3f 2f
   803367620      Controller chn  2 0e 03         :11
   803367747      Controller chn  2 0f 00          :12
   803367747      Controller chn  2 23 3f
   803367747      Controller chn  2 02 00
   803367875         NoteOff chn  2 3f 7f
   803395780      Controller chn  2 0e 03        : 13
   803395907      Controller chn  2 15 00
   803395908      Controller chn  2 16 7f
   803395908      Controller chn  2 17 01
   803395908      Controller chn  2 18 00
   803395908      Controller chn  2 35 00
   803395908      Controller chn  2 36 00
   803395908      Controller chn  2 37 00
   803395908      Controller chn  2 38 00
   803395908      Controller chn  2 0f 00        :14
   803395908      Controller chn  2 23 45
   803395908      Controller chn  2 29 01
   803395908      Controller chn  2 02 36
   803395908      Pitch Bend chn  2 00 3b
   803396034          NoteOn chn  2 45 36
   803424965      Controller chn  2 0e 03
   803425091      Controller chn  2 0f 00
   803425091      Controller chn  2 23 45
   803425091      Controller chn  2 02 00
   803425219         NoteOff chn  2 45 7f
   803459524      Controller chn  1 0e 03
   803459651      Controller chn  1 0f 00
   803459652      Controller chn  1 23 3c
   803459652      Controller chn  1 02 00
   803459779         NoteOff chn  1 3c 7f

List 2 (obtained by Ardour Midi Tracer) of MIDI messages on output virtual IAC Bus 2 , after reading the MIDI file:

   809800898      Controller chn  1 0e 03
   809801023      Controller chn  1 02 39
   809801023      Controller chn  1 0f 00
   809801023      Controller chn  1 15 00
   809801023      Controller chn  1 16 00
   809801023      Controller chn  1 17 00
   809801023      Controller chn  1 18 00
   809801023      Controller chn  1 23 3c
   809801023      Controller chn  1 29 01
   809801023      Controller chn  1 35 00
   809801023      Controller chn  1 36 00
   809801023      Controller chn  1 37 00
   809801023      Controller chn  1 38 00
   809801023      Pitch Bend chn  1 00 40
   809801159          NoteOn chn  1 3c 39
   809837510      Controller chn  2 0e 03
   809837635      Controller chn  2 02 2f
   809837635      Controller chn  2 0f 00
   809837635      Controller chn  2 15 7f
   809837635      Controller chn  2 16 01
   809837635      Controller chn  2 17 00
   809837635      Controller chn  2 18 00
   809837635      Controller chn  2 23 43
   809837635      Controller chn  2 29 01
   809837635      Controller chn  2 35 00
   809837635      Controller chn  2 36 00
   809837635      Controller chn  2 37 00
   809837635      Controller chn  2 38 00
   809837635      Pitch Bend chn  2 50 40
   809837759          NoteOn chn  2 43 2f
   809877697      Controller chn  2 02 00
   809877697      Controller chn  2 23 43            : 1, 2 are missing
   809877823         NoteOff chn  2 43 7f
   809898048      Controller chn  2 02 2f
   809898048      Controller chn  2 15 01
   809898048      Controller chn  2 16 01
   809898048      Controller chn  2 17 7f
   809898048      Controller chn  2 23 3f
   809898048      Pitch Bend chn  2 00 45        : 3,4,5,6,7,8,9,10 are missing
   809898185          NoteOn chn  2 3f 2f
   809931460      Controller chn  2 02 00
   809931460      Controller chn  2 23 3f         : 11,12 are missing
   809931585         NoteOff chn  2 3f 7f
   809959623      Controller chn  2 02 36       : 13,14 are missing
   809959623      Controller chn  2 15 00
   809959623      Controller chn  2 16 7f
   809959623      Controller chn  2 17 01
   809959623      Controller chn  2 18 00
   809959623      Controller chn  2 23 45
   809959623      Controller chn  2 29 01
   809959623      Controller chn  2 35 00
   809959623      Controller chn  2 36 00
   809959623      Controller chn  2 37 00
   809959623      Controller chn  2 38 00
   809959623      Pitch Bend chn  2 00 3b
   809959747          NoteOn chn  2 45 36
   809988673      Controller chn  2 0e 03
   809988797      Controller chn  2 02 00
   809988797      Controller chn  2 0f 00
   809988797      Controller chn  2 23 45
   809988935         NoteOff chn  2 45 7f
   810023235      Controller chn  1 0e 03
   810023359      Controller chn  1 02 00
   810023359      Controller chn  1 0f 00
   810023359      Controller chn  1 23 3c
   810023485         NoteOff chn  1 3c 7f
#2

Perhaps check if in the recorded MIDI file are the messages there also missing?
(GitHub - markc/midicomp: A MIDI Compiler - convert SMF MIDI files to and from plain text)

You also seem to be sending A LOT of MIDI messages with the same timestamp [1].
And run Ardour apparently at 128 samples / cycle. Perhaps there are dropouts at this low buffersize?

–

[1] PS. Keep in mind that physical MIDI is only 32kbaud. So a single CC messages take about 1ms to transmit. It should not directly matter inside virtual busses, but will matter if you plan to send those messages elsewhere.

#3

Thanks for your reply and comments.

Here is the file.mid of the track translated by midicomp that shows that this midi file coincides with the List 2 above where few midi messages are missing.
There are additional “Sequencer Specific midi messages” like:
23500 SeqSpec 99 01 95 dc 24

I also tried to use Ardour with 512 samples / cycle (10.7 ms buffer), but the problem is the same.

Rem: I am using these few additional CC messages prior to ‘note On’ and ‘Note off’ to put informations related to the musical system that i am using. They should be ignored by a standard synthetizer.

Do you have some idea or advice how i can resolve my problem of missing messages please? (i would like to record and re-play all the midi messages).

I could put more time distance dt between messages? dt > 5ms ? it seems long if i have many CC messages associated to one ‘note on’. Also this may be not the origin of the problem here, since i am using virtual busses internal to a performant Mac Pro.

Using Sysex instead? but then i am afraid that they could be not recorded.

Put less messages with the same timestamp?

Frederic.

Midi file


MFile 0 1 19200
MTrk
23400 Par ch=1 c=14 v=3
23500 Par ch=1 c=2 v=57
23500 Par ch=1 c=15 v=0
23500 Par ch=1 c=21 v=0
23500 Par ch=1 c=22 v=0
23500 Par ch=1 c=23 v=0
23500 Par ch=1 c=24 v=0
23500 Par ch=1 c=35 v=60
23500 Par ch=1 c=41 v=1
23500 Par ch=1 c=53 v=0
23500 Par ch=1 c=54 v=0
23500 Par ch=1 c=55 v=0
23500 Par ch=1 c=56 v=0
23500 Pb ch=1 v=8192
23500 SeqSpec 99 01 95 dc 24
23610 On ch=1 n=60 v=57
52690 Par ch=2 c=14 v=3
52790 Par ch=2 c=2 v=47
52790 Par ch=2 c=15 v=0
52790 Par ch=2 c=21 v=127
52790 Par ch=2 c=22 v=1
52790 Par ch=2 c=23 v=0
52790 Par ch=2 c=24 v=0
52790 Par ch=2 c=35 v=67
52790 Par ch=2 c=41 v=1
52790 Par ch=2 c=53 v=0
52790 Par ch=2 c=54 v=0
52790 Par ch=2 c=55 v=0
52790 Par ch=2 c=56 v=0
52790 Pb ch=2 v=8272
52790 SeqSpec 99 01 95 dc 33
52890 On ch=2 n=67 v=47
84840 Par ch=2 c=2 v=0
84840 Par ch=2 c=35 v=67				:1,2, missing
84840 SeqSpec 99 01 95 dc 36
84940 Off ch=2 n=67 v=127
101120 Par ch=2 c=2 v=47
101120 Par ch=2 c=21 v=1
101120 Par ch=2 c=22 v=1
101120 Par ch=2 c=23 v=127
101120 Par ch=2 c=35 v=63
101120 Pb ch=2 v=8832			: 3,4,5,6,7,8,9,10 are missing
101120 SeqSpec 99 01 95 dc 3d
101230 On ch=2 n=63 v=47
127850 Par ch=2 c=2 v=0
127850 Par ch=2 c=35 v=63		: 11,12 are missing
127850 SeqSpec 99 01 95 dc 40
127950 Off ch=2 n=63 v=127
150380 Par ch=2 c=2 v=54		: 13,14 are missing
150380 Par ch=2 c=21 v=0
150380 Par ch=2 c=22 v=127
150380 Par ch=2 c=23 v=1
150380 Par ch=2 c=24 v=0
150380 Par ch=2 c=35 v=69
150380 Par ch=2 c=41 v=1
150380 Par ch=2 c=53 v=0
150380 Par ch=2 c=54 v=0
150380 Par ch=2 c=55 v=0
150380 Par ch=2 c=56 v=0
150380 Pb ch=2 v=7552
150380 SeqSpec 99 01 95 dc 4d
150480 On ch=2 n=69 v=54
173620 Par ch=2 c=14 v=3
173720 Par ch=2 c=2 v=0
173720 Par ch=2 c=15 v=0
173720 Par ch=2 c=35 v=69
173720 SeqSpec 99 01 95 dc 52
173830 Off ch=2 n=69 v=127
201270 Par ch=1 c=14 v=3
201370 Par ch=1 c=2 v=0
201370 Par ch=1 c=15 v=0
201370 Par ch=1 c=35 v=60
201370 SeqSpec 99 01 95 dc 57
201470 Off ch=1 n=60 v=127
201470 Meta TrkEnd
TrkEnd
#4

Looking at the lists above, I have realized that Ardour does not record a new CC message if the value is unchanged, it ignore the message instead. Is it correct?
I didn’t expected this, and this is not compatible with the use i have of the midi messages in my project. But i will adapt my strategy to this situation.