Parameters

The Parameters button in the RQ editor allows to edit global quantization parameters (for all segments).

Segment quantification parameters

These parameters are segment-dependant and can be edited for each segment :

• Tempo: specifies the tempo or the range of tempos used to quantize the durations.

  • If tempo is nil, the algorithm will try various values of tempo by cutting each segment into equal parts, considering each part as a beat, such that the tempo is between 40 and 200 bpm
  • You can specify a particular tempo value by setting the tempo value as a number. The input tempo value will be approximated so that the length of the segment is an integer multiple of the length of a beat.
  • You can specify the range of tempos by setting the tempo value as a 2-element list -- e.g (30 300)

• Schema: a list specifying which subdivisions or series of subdivisions are allowed in each beat.

Examples (subdivision scheme):

(2 2 3) specifies that each beat can be cut in 2, then each part can be cut in 2, then each part can be cut again in 3.

Each segment can be cut again, or left as is. For example, with the previous schema, the first half can be cut in 2 while the second half is left uncut. Again, the first quarter can be cut in 3, while the second is not. Nested lists determine alternate possibilities: (2 (2 3) 3) specifies that each beat can be cut in 2, then each part can be cut in 2 or in 3, then each part can be cut again in 3

When a choice is left between various subdivisions, the choice is made in each segment independently of the choices in the other segments. For example, with the previous schema, the first half can be cut in 2 or 3, and the second half can be cut in 2 or 3 independently, the choices can be different in each part.

Deeper nested lists can be used in order to describe alternate series of subdivisions. More generally, when the current depth is odd, the list describes successive choices, and when it is even, the list alternative choices. For example, the schema (2 ((2 3) (3 2))) specifies that each beat can be cut in 2, then each part can be cut in 2 then 3, or in 3 then 2.

The schema ((((2 3) (3 2) 2) (5 (2 3)) 7)) is equivalent to leaving the choice between the following schemas : (2 3 2), (3 2 2), (5 2), (5 3), (7).

More examples and further explanations can be found in the references given in the "Further Reading" section.

• Nb. solutions: specifies the number of solutions computed and displayed in the k-best panel for each tempo.
• Precision : specifies how the balance between distance (dist) and complexity (comp) in the quantification algorithm. If precision=0, the solutions are ranked only according to comp. If precision=1, the solutions are ranked only according to dist.
• Grace pen.: specifies the penalty given to grace notes. When =0, grace notes are not penalized at all.
• Merge tempi : when this option is ticked, the solutions are ranked across all tempi. The best solution thus gives the best tempo. However, it is not possible to compute more solutions for one particular tempo. When this option is not ticked, the solutions are ranked for each tempo independently. There is no estimation os which tempo is best, but it is possible to compute more solutions for one particular tempo. Both cases are equivalent in terms of computation time.
• Segments = beats : Use this option when the input has been segmented beforehand in beats. The algorithm will consider each segment as a beat (or any number of beats), and will not run the tempo estimation phase.
• Nb. beats/segment : This option is used to specify how long each segment is supposed to last (in beats). This parameter is only used when "Segment = beats" is enabled.

Note: To edit the quantization parameters for one segment only, double-click the corresponding segmentation mark. You can then re-run the algorithm on this segment only by select it and press Q, which can save a lot of computation time.

Segmentation parameters

This parameter concerns the general segmentation algorithm.

• New-segment penalty: sets the penalty given to the creation of a new segment in the segmentation algorithm. The higher it is, the longer the segments are going to be.

Tempo smoothing parameters

These parameters concern the tempo-smoothing algorithm.

• Smoothing : Sets the balance between the smoothness of the tempi and the quality of the solutions. When smoothing=1, the variations of tempo only are taken into account, the best sequence of tempi is chosen, regardless of the fitness of the solutions. When smoothing=0, the weight only is taken into account, the solutions chosen are all the best ones, regardless of their tempi.

• Tempo jump penalty : Sets the penalty given to a jump of tempo. When it is high, the algorithm will find the solutions such that an average tempo is kept over all the segments. When it is low, big tempo changes will be more frequent.