Add a migration script for Bitwig

This sadly has to be a semi-manual process, but at least it works!

tools/migration/migrate-bitwig.py

@@ -0,0 +1,206 @@
+#!/usr/bin/env python3
+
+import argparse
+import glob
+import os
+import re
+import textwrap
+
+
+# Bitwig's project file format is not documented, bot that's not a problem for
+# us! Luckily Bitwig stores the path to the VST3 bundle right next to the VST3
+# class ID, so we can just look for those paths. This will capture the path to
+# the VST3 bundle as well as the class ID.
+BITWIG_VST3_RE = re.compile(
+    rb"(/home/[^/]+/.vst3/yabridge/.+\.vst3)\n([0-9a-zA-Z]{32})"
+)
+
+
+parser = argparse.ArgumentParser(
+    description="Migrate old yabridge VST3 plugin instances in Bitwig project files."
+)
+parser.add_argument(
+    "filename", type=str, help="The .bwproject project file to migrate."
+)
+
+# As a safety measure we want to limit the file names we accept
+args = parser.parse_args()
+
+filename = args.filename
+file_stem, file_extension = os.path.splitext(filename)
+if file_extension.lower() != ".bwproject":
+    print("For safety reasons, only '*.bwproject' files are accepted")
+    exit(1)
+if file_stem.endswith("-migrated"):
+    print("This project file has already been migrated to the new format")
+    exit(1)
+
+migrated_filename = file_stem + "-migrated" + file_extension
+if os.path.exists(migrated_filename):
+    print(
+        f"'{migrated_filename}' already exists, back it up and move it elsewhere "
+        "if you want to redo the migration"
+    )
+    exit(1)
+
+print(
+    "\n".join(
+        textwrap.wrap(
+            f"This script will go through '{filename}' to migrate old yabridge VST3 plugin instances. "
+            f"The output will be saved to '{migrated_filename}', but make sure to still create a backup of the original file in case something does go wrong. "
+            f"Migrating Bitwig project files is a two stop process. ",
+            width=80,
+            break_on_hyphens=False,
+        )
+    )
+)
+print()
+
+print(
+    "\n".join(
+        textwrap.wrap(
+            f"First this script will rewrite the .bwproject file to use thew new plugin IDs. "
+            f"For every yabridge VST3 plugin found you will be prompted with the question if you want to migrate it. "
+            f"Answer 'yes' for all old yabridge VST3 plugin instances, and 'no' if this instance should not be migrated (for instance if you have a project file with mixed old and new instances). ",
+            width=80,
+            break_on_hyphens=False,
+        )
+    )
+)
+print()
+
+print(
+    "\n".join(
+        textwrap.wrap(
+            f"After that you will be asked to open the new '{migrated_filename}' project. "
+            f"During this process you should make that all other Bitwig projects are closed. "
+            f"When opening the new project you will notice that the migrated plugins will try to load but then fail because they cannot load their preset files. "
+            f"At this point you should tell this script to continue, and it will rewrite the preset files. "
+            f"If you then save and reopen the project, everything should work again. "
+            f"Make sure to test whether the new project works immediately after finishing this migration process.",
+            width=80,
+            break_on_hyphens=False,
+        )
+    )
+)
+print()
+
+# We'll first through the original file, and prompt to replace all VST3 class
+# IDs we come across. See `WineUID` in yabridge's source code for an
+# explanation of this conversion. After this we'll have to modify the
+# compressed `.vstpreset` files contained in the file, so we keep track of the
+# UID replacements we'll have to make.
+uid_bytes_replacements = {}
+with open(filename, "rb") as f_input, open(migrated_filename, "xb") as f_output:
+    # Since this is a binary file format, we can't do this on a lien by line
+    # basis like we did for REAPER project files
+    migrated_file = f_input.read()
+
+    # Bitwig sprinkles these class IDs all over the file, so we cannot just
+    # iterate over `BITWIG_VST3_RE.finditer(migrated_file)` and we need to do
+    # some mass replacements instead. Luckily every class ID in the file is
+    # followed by two null bytes, so that should reduce false positives
+    # greatly. We convert the matches to a set first because there will be
+    # duplicates.
+    yabridge_plugins = set(BITWIG_VST3_RE.findall(migrated_file))
+
+    for (plugin_path, wine_uid) in yabridge_plugins:
+        removeme = wine_uid
+
+        plugin_path = plugin_path.decode("utf-8")
+        wine_uid = bytearray.fromhex(wine_uid.decode("ascii"))
+        converted_uid = wine_uid.copy()
+
+        converted_uid[0] = wine_uid[3]
+        converted_uid[1] = wine_uid[2]
+        converted_uid[2] = wine_uid[1]
+        converted_uid[3] = wine_uid[0]
+
+        converted_uid[4] = wine_uid[5]
+        converted_uid[5] = wine_uid[4]
+        converted_uid[6] = wine_uid[7]
+        converted_uid[7] = wine_uid[6]
+
+        print(f"Found '{plugin_path}' with class ID '{wine_uid.hex().upper()}'")
+        while True:
+            answer = input("Should this plugin be migrated? [yes/no] ").lower()
+            if answer == "yes":
+                # As mentioned above the class IDs are sprinkled all over the
+                # file. Luckily they're always followed by two null bytes, so
+                # that should greatly reduce the number of false positives
+                wine_uid_bytes = wine_uid.hex().encode("ascii").upper()
+                converted_uid_bytes = converted_uid.hex().encode("ascii").upper()
+                migrated_file = migrated_file.replace(
+                    wine_uid_bytes + b"\0\0",
+                    converted_uid_bytes + b"\0\0",
+                )
+
+                # And we'll also have to rename this UID in the `.vstpreset`
+                # files Bitwig will extract to `~/.BitwigStudio/plugin-states`
+                uid_bytes_replacements[wine_uid_bytes] = converted_uid_bytes
+                break
+            elif answer == "no":
+                break
+            else:
+                print("Please answer only 'yes' or 'no'")
+
+    print()
+    print(
+        f""
+        "\n".join(
+            textwrap.wrap(
+                f"First step of the migration process done, writing the migrated project to '{migrated_filename}'",
+                width=80,
+                break_on_hyphens=False,
+            )
+        )
+    )
+    f_output.write(migrated_file)
+
+print()
+print(
+    "\n".join(
+        textwrap.wrap(
+            f"Now close any Bitwig project you may still have open, and open '{migrated_filename}' instead. "
+            "Check all plugin instances. Migrated old yabridge instances should show up correctly but with an error saying that their plugin state cannot be loaded, that's normal. "
+            "Once you have confirmed that this is the case for all plugins, type 'continue' below to finish the migration process, or press Ctrl+C to abort. ",
+            width=80,
+            break_on_hyphens=False,
+        )
+    )
+)
+while True:
+    if input("Continue? [continue] ") == "continue":
+        break
+
+# Now we'll go through all `.vstpreset` files Bitwig has extracted from the
+# project file and apply the same replacements we made to the .bwproject file.
+# Sadly I couldn't find an easy way to figure out which state files belong to
+# which plugin, so we're going to have to go through all of them.
+for preset_filename in glob.glob(
+    os.path.expanduser("~/.BitwigStudio/plugin-states/**/*.vstpreset"), recursive=True
+):
+    with open(preset_filename, "r+b") as f:
+        # Luckily this format is clearly defined, so this is much easier than
+        # trying to parse the .bwproject files
+        # https://steinbergmedia.github.io/vst3_doc/vstinterfaces/vst3loc.html#presetformat
+        f.seek(8)
+        uid_bytes = f.read(32)
+        if uid_bytes in uid_bytes_replacements:
+            # If the user has marked the plugin this UID belongs to as one that
+            # should be migrated, then we'll overwrite the old UID in these
+            # .vstpreset files
+            f.seek(8)
+            f.write(uid_bytes_replacements[uid_bytes])
+
+print()
+print(
+    "\n".join(
+        textwrap.wrap(
+            f"Now save the project, close it, and reopen '{migrated_filename}'. "
+            "Everything should now once again be fully functional. ",
+            width=80,
+            break_on_hyphens=False,
+        )
+    )
+)

tools/migration/migrate-reaper.py

@@ -48,6 +48,7 @@ print(
             f"Answer 'yes' for all old yabridge VST3 plugin instances, and 'no' for any other VST3 plugin."
             f"Make sure to test whether the new project works immediately after migration.",
             width=80,
+            break_on_hyphens=False,
         )
     )
 )
@@ -85,10 +86,9 @@ with open(filename, "rb") as f_input, open(migrated_filename, "xb") as f_output:
                 + line[wine_uid_end:]
             )
 
+            print(f"Found '{plugin_name}' with class ID '{wine_uid.hex().upper()}'")
             while True:
-                answer = input(
+                answer = input("Should this plugin be migrated? [yes/no] ").lower()
-                    f"Found '{plugin_name}' with class ID '{wine_uid.hex().upper()}'\nShould this plugin be migrated? [yes/no] "
-                ).lower()
                 if answer == "yes":
                     migrated_file.append(migrated_line)
                     break