Import Midi Into Track

Tracktion Engine
1

I’m missing something on importing midi into a track.

    File file{};
    FileChooser fileChooser("Open Midi File", file, "*.mid");

    if (fileChooser.browseForFileToOpen())
    {
         file = fileChooser.getResult();

         FileInputStream stream(file);

         MidiFile midiFile{};

         if (midiFile.readFrom(stream))
         {
		     midiFile.convertTimestampTicksToSeconds();

		     const auto numTracks = midiFile.getNumTracks();
		     for (auto i = 0; i < numTracks; i++)
		     {
	 		     if (auto midiTrack = midiFile.getTrack(i))
			    {
				    midiTrack->extractMidiChannelMessages(1, sequence, false);// ????
			    }
	 	      }
           }
        }

This might not even be the correct approach. Any suggestions are welcome!

2

Bump.

I suppose this boils down to how to get the “sequence” into the track. But, I am stumbling over finding the correct syntax for that.

Or, again, maybe this is the wrong approach?

3

Importing MIDI is actually fairly complex depending on what you want to do. If you just want to take a MIDI file, and create one clip, and match the tempo of the existing edit, try and copy what is done in Edit::createEditForPreviewingFile

Here is a stripped down, untested version:

        if (auto fin = std::unique_ptr<juce::FileInputStream> (file.createInputStream()))
        {
            juce::MidiFile mf;
            mf.readFrom (*fin);
            mf.convertTimestampTicksToSeconds();

            juce::MidiMessageSequence sequence;

            for (int i = 0; i < mf.getNumTracks(); ++i)
                sequence.addSequence (*mf.getTrack (i), 0.0, 0.0, 1.0e6);

            sequence.updateMatchedPairs();

            if (auto mc = track->insertMIDIClip ({ 0.0, 1.0 }, nullptr))
            {
                // add midi notes
                mc->mergeInMidiSequence (sequence, MidiList::NoteAutomationType::none);
                auto length = sequence.getEndTime();

                mc->setPosition ({ { 0.0, length }, 0.0 });
            }
        }

If you have a multi track midi file with tempo changes, and you want all the tracks created, create a media object for the midi file

    ProjectItem::Ptr mo;
    File f (originalFile);

        mo = project.createNewItem (f, ProjectItem::midiItemType(),
                                    f.getFileNameWithoutExtension(),
                                    TRANS("Imported from directory") + ": " + originalFile.getParentDirectory().getFullPathName(),
                                    ProjectItem::Category::imported,
                                    true);

and then paste it into the edit:

        Clipboard::ContentType::EditPastingOptions options (editView.edit, editView.insertPoint, editView.getSelectionManager());
        options.silent = silent;
        options.preferredLayout = preferredLayout;
        options.setTransportToEnd = setTransportToEnd;
        editView.insertPoint.chooseInsertPoint (options.startTrack, options.startTime, false, editView.getSelectionManager());

        if (options.startTrack != nullptr)
        {
            Clipboard::ProjectItems content;

            for (auto& item : importedProjectItems)
                content.itemIDs.push_back ({ item->getID(), {} });

            content.pasteIntoEdit (options);
        }
4

I will get started on this code and see what I can come up with. I may try to implement both scenarios.

Thank yo so much!

5

The code below, which is only slightly modified from your example, works perfectly on the first try!

File file{};
FileChooser fileChooser("Open Midi File", file, "*.mid");

if (fileChooser.browseForFileToOpen())
{
	file = fileChooser.getResult();
	FileInputStream stream(file);

	MidiFile midiFile{};

	if (midiFile.readFrom(stream))
	{
		midiFile.convertTimestampTicksToSeconds();
		juce::MidiMessageSequence sequence;

		for (auto i = 0; i < midiFile.getNumTracks(); i++)
			sequence.addSequence(*midiFile.getTrack(i), 0.0, 0.0, 1.0e6);

		sequence.updateMatchedPairs();

		const auto midiTrack{ dynamic_cast<te::AudioTrack*>(trackPtr.get()) };

		if (auto midiClip = midiTrack->insertMIDIClip({ 0.0, 1.0 }, nullptr))
		{
			// add midi notes
			midiClip->mergeInMidiSequence(sequence, te::MidiList::NoteAutomationType::none);
			auto length = sequence.getEndTime();
			midiClip->setPosition({ { 0.0, length }, 0.0 });
		}
	}
}

When time permits I’ll work on the second example for importing multiple tracks into an edit.

Thank you so much!

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