Emulate 'Handy Guitar Lab' for non-iOS users

[mungewell]

For the new MS-plus (and some G-Series) pedals Zoom provides/sells a 'Handy Guitar Lab' App. But this is only available for iOS.

It seems that this app uses a file ('HGL_AllZDL.lst') to index/reference the available effects for each pedal, in a way similar to the way that Guitar Lab (on PC) uses 'AllZDL7.lst'. In theory, users can use these files/URLs to support their use of the pedals that they have purchased.

Note: We DO NOT condone/share the copyright protected property of Zoom. Our project aims to provide the tools/information for managing the Effects/Presets on the pedals, for use with PC (Linux, Windows and Mac).

@thammer Can you please share the info you have?

[mungewell]

That's a very informative patch. :-)

As I mentioned elsewhere, 'zdownload' is used to grab everything. If a user just wants one or two files, then they can hand assemble the URLs... for each of the ZD2, ZIC, and (where needed) ZIR.

$ wget https://www.zoom.co.jp/archive/GUITAR_LAB/HGL_for_MS50G_Plus/ZDLF/ZNR.zip
--2025-03-07 17:56:45--  https://www.zoom.co.jp/archive/GUITAR_LAB/HGL_for_MS50G_Plus/ZDLF/ZNR.zip
Connecting to www.zoom.co.jp (www.zoom.co.jp)|139.162.106.88|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 11873 (12K) [application/zip]
Saving to: ‘ZNR.zip’

ZNR.zip                           100%[===========================================================>]  11.59K  --.-KB/s    in 0s      

2025-03-07 17:56:45 (82.1 MB/s) - ‘ZNR.zip’ saved [11873/11873]

$ unzip ZNR.zip 
Archive:  ZNR.zip
  inflating: ZNR.ZD2                 
$ python3 ../../decode_effect.py --summary -m ZNR.ZD2 
0x01000070 : ZNR.ZD2, ZNR (v1.10 4.35%), 68dd2d94471b622e7bfaa9192bc866dc

[mungewell]

@thammer There are a few HGL apps for the G-series (G2Four/B2Four/G6/B6/G11), I wonder if these use a similar schema?

https://apps.apple.com/us/app/handy-guitar-lab-for-g6/id1549393871

[thammer]

I decided to remove my original comment with the hotlinked URLs.

My main motivation is to learn more about the inner workings of these pedals, with focus on the patches. I hope to add to the usefulness of these pedals by creating a good web-based editor for all the MS and MS+ pedals, so you don't need an iPhone to edit patches on a bigger screen than on the pedal itself. I hope this will make the pedals more attractive to users/customers. I love the Zoom multistomps and own more than a handful of them.

Having access to the effect files and analyzing them with tools like zoom-zt2 makes it easier for me to improve the web-based patch editor (at https://sym.bios.is/ and https://github.com/thammer/zoom-explorer).

The information below is aimed at developers wanting to learn more about the inner workings of the Zoom range of effect pedals.

I used the iOS app Charles Proxy to list all the URLs that are accessed by the "GL for MS-70CDR+" iOS app.

To get as many URLs as possible, I uninstalled the "GL for MS-70CDR+" app and then reinstalled it (to remove all previously downloaded data from my phone). Then I started Charles Proxy, and then ran the "GL for MS-70CDR+" app. Charles Proxy then listed the URL for the effect list and for all the ZD2, ZIC and ZIR files.

The effect files can be download using zdownload from here: https://github.com/fuzboxz/zdownload/tree/master.

With the following diff, to support trailing commas in object property lists in json, handle 404 errors (missing files), and allow specifying the effect list file name and the relative path to the effects on the command line:

diff ./zdownload-plus.py ./zdownload.py
1,2c1
< import sys, requests, json5, os
<
---
> import sys, requests, json, os
8,18c7
< if len(sys.argv) != 3:
<     print("Usage: zdownload-plus.py <.lst relative path> <file relative path>")
<     exit()
<
< base_url = "http://www.zoom.co.jp/archive/GUITAR_LAB/"
<
< lst_url = base_url + sys.argv[1]
< zdl_url = base_url + sys.argv[2] + "/"
<
< r = requests.get(lst_url)
< print("Downloading .lst file from URL: " + lst_url)
---
> zdl_url = "http://www.zoom.co.jp/archive/ZDLM/ZDLF3/"
19a9
> r = requests.get("https://www.zoom.co.jp/archive/ZDLM/AllZDL3.lst")
21,22c11,17
<     data = json5.loads(r.text)
<
---
>     data = json.loads(r.text)
>
>     #download url might change
>     print("Download URL: " + data.get("zdl_url"))
>     if zdl_url != data.get("zdl_url"):
>         zdl_url = data.get("zdl_url")
>
35c30,33
<             # create folder structure and clean up purgescript
---
>             print(devicename)
>
>             # create folder structure and clean up purgescript
>
59a58
>                         print(noext)
61,63c60
<                         full_url = zdl_url+filename
<                         print(devicename + " - " + noext.ljust(10) + " - " + full_url)
<                         r = requests.get(full_url)
---
>                         r = requests.get(zdl_url+filename)
67,73c64,67
<                         try:
<                             with zipfile.ZipFile(archive_path,'r') as zipObj:
<                                 zipObj.extractall(path)
<                             #remove zip
<                             os.remove(archive_path)
<                         except:
<                             print("Error extracting " + noext + " - SKIPPING")
---
>                         with zipfile.ZipFile(archive_path,'r') as zipObj:
>                             zipObj.extractall(path)
>                         #remove zip
>                         os.remove(archive_path)

So, for instance, if you have the Zoom MS-70CDR+ pedal, you would run Charles Proxy while running the "GL for MS-70CDR+" iOS app for the first time. Charles Proxy will show you the URL for the .lst file and for the effect files.

You would then run python zdownload.py HGL_for_MS70CDR_Plus/HGL_AllZDL.lst HGL_for_MS70CDR_Plus/ZDLF.

Likewise, if you have the Zoom G11 pedal, Charles Proxy would tell you the URLs, and you'd run python zdownload.py AllZDL7_2.lst ZDLF7_2

[thammer]

@thammer There are a few HGL apps for the G-series (G2Four/B2Four/G6/B6/G11), I wonder if these use a similar schema?

The procedure for downloading effect files is the same for these pedals, yes. Charles Proxy will tell you the URLs you need when you run the Guitar Lab app for the first time, and the patched zdownload.py can download the files.

[mungewell]

Took a little while to try this out as my laptop was seriously out-of-date. Minor issue that there were some stripped trailing spaces in the 'diff' (maybe how I grab it).

But I was able to download the MS-plus effects. :-)

[mungewell]

It seems some of the 200D+ effects do not decode correctly, looks like I'll need to tweak.

zoom_fx/MS200DPLUS$ python3 ../../../../decode_effect.py -s -m COESC7G8.ZD2
Traceback (most recent call last):
  File "/home/simon/zoom-zt2-sdw-github/zoom_fx_ms-plus/success/zoom_fx/MS200DPLUS/../../../../decode_effect.py", line 281, in <module>
    main()
  File "/home/simon/zoom-zt2-sdw-github/zoom_fx_ms-plus/success/zoom_fx/MS200DPLUS/../../../../decode_effect.py", line 135, in main
    config = zoomzt2.ZD2.parse(data)
             ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 405, in parse
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 417, in parse_stream
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 429, in _parsereport
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 2239, in _parse
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 429, in _parsereport
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 2773, in _parse
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 429, in _parsereport
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 2239, in _parse
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 429, in _parsereport
  File "/usr/local/lib/python3.12/dist-packages/construct-2.10.70-py3.12.egg/construct/core.py", line 2848, in _parse
construct.core.ConstError: Error in path (parsing) -> DATA
parsing expected b'DATA' but parsed b'INF2'

[josephcomer]

Hi Folks. New here, but I have a 50+, and I'm trying to see how far I can take it.

@thammer I'm having an awful time trying to get the diff you posted above to apply to the original python script. I hate to be "that guy", but is there a way I can download the script with the diffs already applied? (I'm on windows, tried command line stuff, Beyond Compare, notepad++ and Tortoise Merge, but they all crapped out.) Thank you.

[mungewell]

@josephcomer Not sure that this is 100% as @thammer wrote... but I believe it works:
zdownload-plus.py.txt

$ python3 zdownload-plus.py 'HGL_for_MS70CDR_Plus/HGL_AllZDL.lst' 'HGL_for_MS70CDR_Plus/ZDLF'
Downloading .lst file from URL: http://www.zoom.co.jp/archive/GUITAR_LAB/HGL_for_MS70CDR_Plus/HGL_AllZDL.lst
BPM_MDL already exists - SKIPPING
COMP already exists - SKIPPING
RACKCOMP already exists - SKIPPING
GRAYCOMP already exists - SKIPPING
OPTCOMP already exists - SKIPPING
...

[josephcomer]

Thanks so much! I'll give it a shot! :)