added tool to fix deprecated id3 tags in flacs

flac_update_id3

@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+
+import logging
+import os
+import pathlib
+import pprint
+import re
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+comment_re = re.compile('    comment\[[0-9]+\]: (?P<tag_name>[^=]+)=(?P<tag>.*)')
+
+
+def run(cmd):
+    p = subprocess.run(cmd, capture_output=True)
+    return (p.stdout.decode('UTF-8'), p.stderr.decode('UTF-8'), p.returncode)
+
+
+def get_tags(filename):
+    tags = {}
+    cmd = ('/usr/bin/metaflac', '--list', '--block-type=VORBIS_COMMENT', filename)
+    stdout, stderr, exit_code = run(cmd)
+    stdout = stdout.split('\n')
+    logging.debug(f'stdout: {stdout}')
+    logging.debug(f'stderr: {stderr}')
+    logging.debug(f'exit: {exit_code}')
+    if exit_code != 0:
+        sys.exit(stderr)
+    for line in stdout:
+        match = comment_re.search(line)
+        if match:
+            tags[match.group('tag_name')] = match.group('tag')
+    return tags
+
+
+def writable(filename):
+    return os.access(filename, os.R_OK)
+
+
+def ffmpeg_encode(input_file, output_file):
+    cmd = ('/usr/bin/ffmpeg', '-loglevel', 'error', '-i', input_file, output_file)
+    stdout, stderr, exit_code = run(cmd)
+    if exit_code != 0:
+        logging.fatal(stderr)
+
+
+def write_flac(input_wav, tags, output_flac):
+    cmd = ['/usr/bin/flac', '-f', '-s', '--best']
+    tags = [f'{tag_type}={tag}' for tag_type, tag in tags.items()]
+    logging.debug(tags)
+    for tag in tags:
+        cmd.append('-T')
+        cmd.append(tag)
+    cmd.append(input_wav)
+    cmd.append('-o')
+    cmd.append(output_flac)
+    _, stderr, exit_code = run(cmd)
+    if exit_code != 0:
+        sys.exit(stderr)
+
+
+def replace_original(new, old):
+    try:
+        os.rename(new, old)
+    except:
+        logging.error(f'Failed to replace {old} with {new}.')
+        pprint.pprint(get_tags(old))
+        sys.exit(1)
+
+def main():
+    logging.basicConfig(encoding='utf-8', level=logging.DEBUG)
+    if len(sys.argv) != 2:
+        sys.exit('Give a flac with id3 tags.')
+
+    full_flac = pathlib.Path(sys.argv[1]).resolve()
+
+    if not writable(full_flac):
+        sys.exit(f'{full_flac} is not writable.')
+
+    stem = full_flac.stem
+    file = full_flac.name
+    path = full_flac.parent
+
+    logging.debug(f'stem: {stem}')
+    logging.debug(f'file: {file}')
+    logging.debug(f'path: {path}')
+    tags = get_tags(full_flac)
+
+    with tempfile.TemporaryDirectory(dir='/dev/shm') as working_dir:
+        with tempfile.NamedTemporaryFile(dir=path, delete=False) as temp_flac:
+            full_wav = working_dir / pathlib.Path(stem + '.wav')
+
+            ffmpeg_encode(full_flac, full_wav)
+            write_flac(full_wav.as_posix(), tags, temp_flac.name)
+            cmd = ('/usr/bin/flac', '-t', temp_flac.name)
+            stdout, stderr, exit_code = run(cmd)
+            print(f'stdout: {stdout}')
+            print(f'stderr: {stderr}')
+            print(f'exit code: {exit_code}')
+            pprint.pprint(get_tags(temp_flac.name))
+            replace_original(temp_flac.name, full_flac)
+
+if __name__ == '__main__':
+    main()