Syncing SMF file with audio

[Thorste]

Arlo,
I tried your suggestion of using Sweet Midi Player to play midi files from SLM
Those midi files are sending note data and CC commands to a Voicelive Touch harmonizer.
The Sweet Midi Player does start with the Start Sequence command, but there is a delay of about a second after I select the song in SLM, which results with the harmonizer firing at the wrong spot.

 I have also sent the midi from SLM on 1 iPad to Sweet Midi Player on another iPad and there isn't any delay in firing to the harmonizer.

I'm surprised it works sending midi to another ipad, but sending midi to another app on the same ipad using Virtual Midi results in a delay.

Have you noticed any delays?

Thor

[arlo]

Where exactly is the delay? If it's in Set List Maker sending the start message to Sweet MIDI Player, I don't understand how that would lead to "the harmonizer firing at the wrong spot" once the MIDI file has started playing.

Does everything play correctly if you play the file from Sweet MIDI Player manually? How about if you play the file from SMP manually, then move SMP to the background?

[Thorste]

Arlo,
I'm sorry I didn't let you know the midi played by Sweet Midi is while a recording is played by SLM.
That is why the delay in starting the file playback in Sweet Midi is firing at the wrong time since the recording in SLM has started playing before the midi file in Sweet Midi has started.
I checked and found the send midi delay was at one second and changed it to zero but the delay still occurred.
Should I send you the tech support email that contains my settings or perhaps the preference file?

Thor

[arlo]

Okay, I just split this into a new topic since it's not primarily about setting up the connection to Sweet MIDI Player.

So you are trying to use Sweet MIDI Player to send MIDI messages to a hardware device, and sync that with audio playback in Set List Maker? How many MIDI messages are you sending? Have you looked at Set List Maker's automation tracks as a way to do that?

[Pongo]

I'm using SLM in a similar way. I use the Automation feature to play a recording, while also sending MIDI CC and program changes to my TC Helicon Voicelive 2 harmonizer.

IMHO, if you can record/mix the SMF into a new version of the recording and then use the automation to trigger your harmonizer...life will be a bit easier.

[Thorste]

Arlo,
I'm sending a start sequence command to SMP which plays a midi file that sends midi data to another hardware device. There is a delay before the mid file plays of less than a second after a select the song. Automation has the recording playing and sending of midi, as well as start tempo ( beat clock), on song selection.

This is all happening on one iPad.

If I make use of two iPads and send midi out to Sweet Midi Player on another iPad  from SLM ther is no delay.

I have about 50 midi events including 30 note events. In order to use these note events in the automation, do I have to use a velocity of zero for a note off event?

I'm sending notes to the harmonizer for smart harmony purposes.

[Pongo]

Is the Voicelive the only piece of external MIDI gear in your setup?

Are you playing a backing track (mp3) from SLM while attempting to send CC and Note on/off data to the VL box?

If so...why do you even need SMP, since you can just manually enter the MIDI data into an automation track, by creating MIDI presets in SLM for your VLT patches? Sure, it would take a bit of time to do, but it might give you a better (more stable) performance in the long run.

[Thorste]

@Pongo

That's what I probably should do.
Have you done this with....note on and offs for the harmony chords?
I'm assuming each pitch will need note on and off commands.
Would I need to do the "workaround" of using a velocity of zero to represent a note off command?

Thor

[Pongo]

Sort of.

I have a bunch of MIDI presets that I created in SLM that are sent to my VL2 box via an automation track for the song. If all I want to do is turn on/off the harmony (or delay, reverb, doubling, f/x, etc.), I create another [new] MIDI preset that only sends a CC event. I record/add that to the same automation track to toggle on or off the last preset parameter that was changed.

[Thorste]

So you have never sent note on or offs in the automation track?
I'm just trying to find a quick way to do it.
I guess midi learn and play the notes or maybe it only will read one note at a time.

[arlo]

I'm sending a start sequence command to SMP which plays a midi file that sends midi data to another hardware device. There is a delay before the mid file plays of less than a second after a select the song. Automation has the recording playing and sending of midi, as well as start tempo ( beat clock), on song selection.
This is all happening on one iPad.
If I make use of two iPads and send midi out to Sweet Midi Player on another iPad  from SLM ther is no delay.

What happens if you use the two iPads, but put Sweet MIDI Player into the background on the other iPad? That will tell us if the problem is related to SMP being in the background (which it would have to be when running on one iPad).

I have about 50 midi events including 30 note events. In order to use these note events in the automation, do I have to use a velocity of zero for a note off event?

Would you be sending the same 30 note messages for each song, or would you be sending a different set of 30 messages for each song?

[Pongo]

So you have never sent note on or offs in the automation track?
I'm just trying to find a quick way to do it.
I guess midi learn and play the notes or maybe it only will read one note at a time.

Are you sending note on/off data so that the harmonizer knows what harmony to generate based on that note?

I've never used the VLT, but the VL2 allows me to feed audio into it (guitar, or the backing track) to set the harmony note(s) for me.
Perhaps your VLT does not have that feature.

[Thorste]

@ Arlo,
I've tested SMP on the second ipad in the background and the delay occurs as it does when using only one ipad with SMP in the background. This does not happen with SMP in the foreground. Thanks for the troubleshooting tip. Is this something that needs to be brought up with SMP developer or can we find a way to fix this on our own?

As far as the midi events, they will change depending on the song. Sometimes more and sometimes less. The events are notes sent to the harmonizer to figure out harmony chord, as well as midi CCs to toggle harmony on and off. Pong has an idea that might circumvent my having to do that by sending the backing track to the harmonizer aux input which then figures out the chords. I don't know how accurate it is though.

Thor

@Pongo,
The Voicelive touch does have an aux input for backing tracks. I haven't tried it yet. Is it fairly accurate on analyzing chords?

Thor

[Pongo]

It works great on the VL2, but you may want to turn off the aux `output', so that your VLT only hears the backing track, but doesn't send it to the outputs. This way, by using a splitter, you can still send the backing track to your PA directly.

IMHO, this will be much easier for you than using SMP the send the note on/off information. As I mentioned, you just need to create a new MIDI preset in SLM for each of your VLT patches and then add them to your automation track.

[arlo]

I've tested SMP on the second ipad in the background and the delay occurs as it does when using only one ipad with SMP in the background. This does not happen with SMP in the foreground. Thanks for the troubleshooting tip. Is this something that needs to be brought up with SMP developer or can we find a way to fix this on our own?

It wouldn't hurt to ask, he's always had good answers for my questions, but it would be helpful to do some more testing first and try to learn more about when the delay does and does not occur. For example, is there a delay on the first message you send, but not on subsequent messages sent within a short amount of time? Or is there a delay when SMP is not yet playing audio, but no delay while it is playing audio?

Since the problem only occurs when the app is in the background, I'm thinking it is related to iOS's functionality to put apps to sleep when they are in the background. Unfortunately, developers have little control over that, but Rolf might have some ideas if you can give him more details about what's happening.