Encode multiple tracks concurrently

src/main.py

@@ -3,6 +3,7 @@ import subprocess
 import shutil
 from subprocess import CalledProcessError
 from pathlib import Path
+from multiprocessing import Pool
 
 
 def get_args():
@@ -30,15 +31,22 @@ def skip_album(path: Path):
     return False
 
 
-def transcode(transcode_list: list, encoder: Path):
+def transcode(transcode_list: list, encoder: Path, workers=8):
+    worker_args = [(row[0], row[1], encoder) for row in transcode_list]
+    with Pool(workers) as p:
+        print(p.starmap_async(transcode_worker, worker_args))
+        p.close()
+        p.join()
+
+
+def transcode_worker(in_track, out_track, encoder):
     additional_args = ('--bitrate', '128', '--music')
-    for in_track, out_track in transcode_list:
     subprocess_args = (str(encoder),) + additional_args + (in_track, out_track)
     try:
         result = subprocess.run(subprocess_args, capture_output=True, text=True, check=True)
+        return f"Transcoded '{in_track}' successfully"
     except CalledProcessError:
-            print(f"ERROR: Transcoding of '{in_track}' failed with errors:")
+        return f"ERROR: Transcoding of '{in_track}' failed with errors:\n{result.stderr}"
-            print(result.stderr)
 
 
 def main(input_dir: Path, output_dir: Path, encoder: Path):