Progress reverse engineering OPZ

[patriciogonzalezvivo]

Hi! I want to thank you for the valuable documentation here. With it I manage to make some progress decoding the SYSEX messages from the OP-Z. Like for example:

• sound properties
• key events ( on the non musical keys)
• volumen

My final goal is to be able to print the pattern do you happen to have an example on how to decompress the SYSEX 0x09 message for patterns using zlib?

[lrk]

@patriciogonzalezvivo you can double check, but I'm pretty sure sysex have the same structure as the project files. Have a look at my wiki on that: https://github.com/lrk/z-po-project/wiki/Project-file-format

[patriciogonzalezvivo]

Thanks @lrk ! definitely there are similarities. Notice that when changing the track quantize or note length one of the bytes match the "track chunk" byte offset https://github.com/patriciogonzalezvivo/opz/blob/main/src/OPZ.cpp#L151 that you point out on your documentation: https://github.com/lrk/z-po-project/wiki/Project-file-format#track-chunk
One thing I'm noticing is that the 8bits to/from 7bits conversion is making my scheme more complicated that it should. Any help will be appreciated.

[patriciogonzalezvivo]

Yes @lrk I can confirm that when changing the note length and quantize, it provides the address on memory of the pattern properties, consisting on 16 structs of the same track properties. one for every track
https://github.com/patriciogonzalezvivo/opz/blob/main/src/OPZ.cpp#L44

[patriciogonzalezvivo]

Making solid progress reverse engineering the OP-Z into a library 'libopz' and creating a terminal companion. But seam there are some messages I’m missin… Any idea how to sniff midi between a iOS and the OP-Z?. Here is the library so far (with some examples like this ncurses companion app https://github.com/patriciogonzalezvivo/libopz )

[hyphz]

I used Bome MIDI Translator, set it up to forward BLE midi to and from the OP-Z and the app will connect to it fine.

[patriciogonzalezvivo]

Progress update, figurate how to get the entire patterns data and now I'm moving towards parsing the notes according to the data on the wiki https://github.com/lrk/z-po-project/wiki/Project-file-format#note-chunk
After following all the described data specs still can't make sense of the results. I just want to know when steps have active notes, but the duration, velocity, note and age doesn't seams to match what I have on my OP-Z
Maybe you guys can provide some feedback.

I'm using this example code to print all tracks on a pattern

This is how I'm mapping the notes to the tracks

const size_t opz_notes_offset_track[] = { 0, 2, 4, 6, 8, 12, 16, 24, 28, 29, 30, 31, 35, 41, 47, 51 };
size_t  offset =  _step * 55 + opz_notes_offset_track[_track]; 

This is how the index table look like

          01    02    03    04    05    06    07    08    09    10    11    12    13    14    15    16

   KICK   0     55    110   165   220   275   330   385   440   495   550   605   660   715   770   825
  SNARE   2     57    112   167   222   277   332   387   442   497   552   607   662   717   772   827
   PERC   4     59    114   169   224   279   334   389   444   499   554   609   664   719   774   829
 SAMPLE   6     61    116   171   226   281   336   391   446   501   556   611   666   721   776   831
   BASS   8     63    118   173   228   283   338   393   448   503   558   613   668   723   778   833
   LEAD   12    67    122   177   232   287   342   397   452   507   562   617   672   727   782   837
    ARP   16    71    126   181   236   291   346   401   456   511   566   621   676   731   786   841
  CHORD   24    79    134   189   244   299   354   409   464   519   574   629   684   739   794   849
    FX1   28    83    138   193   248   303   358   413   468   523   578   633   688   743   798   853
    FX2   29    84    139   194   249   304   359   414   469   524   579   634   689   744   799   854
   TAPE   30    85    140   195   250   305   360   415   470   525   580   635   690   745   800   855
 MASTER   31    86    141   196   251   306   361   416   471   526   581   636   691   746   801   856
PERFORM   35    90    145   200   255   310   365   420   475   530   585   640   695   750   805   860
 MODULE   41    96    151   206   261   316   371   426   481   536   591   646   701   756   811   866
  LIGHT   47    102   157   212   267   322   377   432   487   542   597   652   707   762   817   872
 MOTION   51    106   161   216   271   326   381   436   491   546   601   656   711   766   821   876

From which I then can access different note properties:

Notes Duration

          01    02    03    04    05    06    07    08    09    10    11    12    13    14    15    16

   KICK   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00
  SNARE   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00
   PERC   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00
 SAMPLE   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00  0.00
   BASS   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00  0.00
   LEAD   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00  0.00  0.00
    ARP   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00  0.00  0.00
  CHORD   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.39  -0.00
    FX1   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.39  -0.00
    FX2   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.00  0.39  -0.00
   TAPE   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.39  -0.00 0.00
 MASTER   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.39  -0.00 0.00
PERFORM   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.00  0.39  -0.00 0.00
 MODULE   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.04  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00
  LIGHT   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04
 MOTION   0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.00  0.39  -0.00 0.00  0.00  0.04  0.00

Notes Note

          01    02    03    04    05    06    07    08    09    10    11    12    13    14    15    16

   KICK   00    00    22    00    39    40    00    00    02    05    10    00    00    00    00    27
  SNARE   01    05    10    00    00    00    2B    00    3C    40    00    00    01    05    10    00
   PERC   3C    40    00    00    01    05    10    00    00    00    26    00    3C    40    00    00
 SAMPLE   00    22    00    39    40    00    00    02    05    10    00    00    00    00    27    00
   BASS   05    10    00    00    00    2B    00    3C    40    00    00    01    05    10    00    00
   LEAD   22    00    39    40    00    00    02    05    10    00    00    00    00    27    00    3C
    ARP   00    00    01    05    10    00    00    00    26    00    3C    40    00    00    01    05
  CHORD   39    40    00    00    02    05    10    00    00    00    00    27    00    3C    40    00
    FX1   01    05    10    00    00    00    26    00    3C    40    00    00    01    05    10    00
    FX2   00    00    27    00    3C    40    00    00    01    05    10    00    00    00    26    00
   TAPE   40    00    00    02    05    10    00    00    00    00    27    00    3C    40    00    00
 MASTER   05    10    00    00    00    22    00    39    40    00    00    02    05    10    00    00
PERFORM   00    27    00    3C    40    00    00    01    05    10    00    00    00    26    00    3C
 MODULE   27    00    3C    40    00    00    01    05    10    00    00    00    26    00    3C    40
  LIGHT   00    3C    40    00    00    01    05    10    00    00    00    26    00    3C    40    00
 MOTION   01    05    10    00    00    00    2B    00    3C    40    00    00    01    05    10    00

Notes Velocity

          01    02    03    04    05    06    07    08    09    10    11    12    13    14    15    16

   KICK   10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41
  SNARE   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05
   PERC   00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF
 SAMPLE   41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00
   BASS   05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10
   LEAD   00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00
    ARP   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05
  CHORD   FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01
    FX1   10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41
    FX2   05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10
   TAPE   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05
 MASTER   FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01
PERFORM   10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41
 MODULE   41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00
  LIGHT   00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00
 MOTION   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05

Notes Age

          01    02    03    04    05    06    07    08    09    10    11    12    13    14    15    16

   KICK   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05
  SNARE   00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF
   PERC   41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00
 SAMPLE   05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10
   BASS   FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01
   LEAD   10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41
    ARP   00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF
  CHORD   00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00
    FX1   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05
    FX2   FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01
   TAPE   00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF
 MASTER   00    00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00
PERFORM   01    05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05
 MODULE   05    10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10
  LIGHT   10    41    00    00    FF    01    05    10    41    00    00    FF    01    05    10    41
 MOTION   00    FF    01    05    10    41    00    00    FF    01    05    10    41    00    00    FF

@lrk do this looks ok to you? Do you know of a simpler way to get know what steps are active in each track?