This plugin deletes all kinds of doubled, repeated and possibly unnecessary MIDI events:

(click image to enlarge)

Doubled events are events that start at the same musical time (e.g. two C5 note events starting at 2:1:060). These events are often results of e.g. pasting one clip into another. Removing these events manually is a quite lengthy process. You can additionally choose which events are to be kept: Keep the note with the shortest or longest duration, the control event with the lowest or highest data, etc.

Repeated events are events that don't have any effect on the connected midi equipment. For example, sending the same controller event with the same data at the beginning of each bar is only a waste of the very limited bandwidth of the midi connection. But these events can often be found in commercial midi files or in the recordings of e.g. a portable keyboard and its auto accompaniment.

Un-Octaving deletes notes that appear in different octaves. This doubling is often used to 'thicken' string or brass sounds. You can choose which of the doubled notes are to be kept: the notes in the top or the bottom octave. The principle if shown in the following figure, where the highest notes are kept:

Temporary Quantization performs a quantization with the given resolution before the processing starts. After the processing but before sending the events back to the sequencing software, the quantization is undone so that one will effectively never notice any changes in the events’ timing. This option is useful if one wants to delete events that are some kind of doubled but do not start on exaclty the same time.