Add Guix manifest for development purposes

manifest.scm

@@ -0,0 +1,4 @@
+(packages->manifest
+ (list
+  (specification->package "python")
+  (specification->package "python-invoke")))

tasks.py

@@ -0,0 +1,38 @@
+from invoke import task
+from shutil import rmtree, unpack_archive
+from os import mkdir
+from os.path import isdir, basename
+from glob import glob
+from itertools import chain
+from shlex import quote
+
+PREP = "assets"
+OUTPUT = "output"
+
+MUSIC_GLOBS = ["*.flac", "*.mp3", "*.ogg", "*.opus", "*.aac"]
+
+@task
+def clean(c):
+    dirs = [dir for dir in [PREP] if isdir(dir)]
+    for dir in dirs:
+        print(f"Removing {dir}")
+        rmtree(dir)
+
+@task
+def unpack(c):
+   zipfiles = glob("src/*.zip")
+   if not isdir(PREP):
+       mkdir(PREP)
+   for zipfile in zipfiles:
+       unpack_archive(zipfile, PREP)
+
+@task(unpack)
+def probe(c):
+    if not isdir(OUTPUT):
+        mkdir(OUTPUT)
+    music_list = list(chain.from_iterable([glob(f"{PREP}/{pat}") for pat in MUSIC_GLOBS]))
+    for m in music_list:
+        cmd = f"ffprobe -v quiet -print_format json -show_format {quote(m)}"
+        result = c.run(cmd)
+        with open(f"{OUTPUT}/{basename(m)}.json", 'w') as f:
+            f.write(result.stdout)