View source for Talk:TimeStretch

=== default values of the advanced parameters ===

I think the default values that are mentioned in the history, come from this comment in the source of SoundTouch:

 TDStretch.cpp:
 // Sets routine control parameters. These control are certain time constants
 // defining how the sound is stretched to the desired duration.
 //
 // 'sequenceMS' = one processing sequence length in milliseconds (default = 82 ms)
 // 'seekwindowMS' = seeking window length for scanning the best overlapping position (default = 28 ms)
 // 'overlapMS' = overlapping length (default = 12 ms)

I found out that this comment is wrong after a lot of debugging (perhaps it was correct in an older verion of SoundTouch?).

* aa = 64 is set in RateTransposer.cpp (the value doesn't change unless you use the advanced parameter to change it):
 // Constructor
 RateTransposer::RateTransposer() : FIFOProcessor(&outputBuffer)
 {
    bUseAAFilter = true;
 
    // Instantiates the anti-alias filter
    pAAFilter = new AAFilter(64);
    pTransposer = TransposerBase::newInstance();
 }

* overlap is set in TDStretch.h (the value doesn't change unless you use the advanced parameter to change it):
 TDStretch.h:
 #define DEFAULT_OVERLAP_MS      8

* sequence and seekwindow are set in TDStretch.cpp:
 /// Calculates processing sequence length according to tempo setting
 void TDStretch::calcSeqParameters()
 {
    // Adjust tempo param according to tempo, so that variating processing sequence length is used
    // at varius tempo settings, between the given low...top limits
    (...)
    
    if (bAutoSeqSetting)
    {
        seq = AUTOSEQ_C + AUTOSEQ_K * tempo;
        seq = CHECK_LIMITS(seq, AUTOSEQ_AT_MAX, AUTOSEQ_AT_MIN);
        sequenceMs = (int)(seq + 0.5);
    }
 
    if (bAutoSeekSetting)
    {
        seek = AUTOSEEK_C + AUTOSEEK_K * tempo;
        seek = CHECK_LIMITS(seek, AUTOSEEK_AT_MAX, AUTOSEEK_AT_MIN);
        seekWindowMs = (int)(seek + 0.5);
    }
 
    (...)
 }

The default values are set when the code executes:
 sampler = new SoundTouch();

The default values are updated when the code executes:
  sampler->setTempo(_tempo);
  sampler->setPitch(_pitch);

[[User:Admin|Admin]] 23:38, 7 July 2016 (CEST) Wilbert