1 files changed, 130 insertions, 0 deletions
diff --git a/tools/merge-recordings.py b/tools/merge-recordings.py
new file mode 100755
index 0000000..637858e
--- /dev/null
+++ b/tools/merge-recordings.py
@@ -0,0 +1,130 @@
+#!/usr/bin/env python3
+import os
+import re
+import subprocess
+import tempfile
+import sys
+
+from datetime import datetime, timedelta
+from argparse import ArgumentParser
+
+
+fmt = '%d%m%y-%H%M%S'
+
+File = dict
+FileList = list[File]
+
+
+def get_files(source_directory: str) -> FileList:
+    files = []
+    for f in os.listdir(source_directory):
+        m = re.match(r'^(\d{6}-\d{6})_(\d{6}-\d{6})_id(\d+)(_\w+)?\.mp3$', f)
+        if not m:
+            continue
+
+        files.append({
+            'filename': os.path.join(source_directory, f),
+            'start': datetime.strptime(m.group(1), fmt),
+            'stop':  datetime.strptime(m.group(2), fmt)
+        })
+    files.sort(key=lambda f: f['start'].timestamp())
+    return files
+
+
+def group_files(files: FileList) -> list[FileList]:
+    groups = []
+    group_idx = None
+    
+    for info in files:
+        # if group_idx is not None:
+        #     print(info['start'], groups[group_idx][-1]['stop'])
+        #     print('    ', info['start'] - groups[group_idx][-1]['stop'])
+        #     print()
+
+        if group_idx is None or \
+                not groups[group_idx] or \
+                info['start'] - groups[group_idx][-1]['stop'] <= timedelta(seconds=1):
+            if group_idx is None:
+                groups.append([])
+                group_idx = 0
+        else:
+            group_idx += 1
+            groups.append([])
+        groups[group_idx].append(info)
+
+    return groups
+
+
+def merge(groups: list[FileList],
+          output_directory: str,
+          delete_source_files=False,
+          vbr=False) -> None:
+    for g in groups:
+        success = False
+
+        fd = tempfile.NamedTemporaryFile(delete=False)
+        try:
+            for file in g:
+                line = f'file \'{file["filename"]}\'\n'
+                # print(line.strip())
+                fd.write(line.encode())
+            fd.close()
+
+            start = g[0]['start'].strftime(fmt)
+            stop = g[-1]['stop'].strftime(fmt)
+            fn = f'{start}_{stop}_merged.mp3'
+            output = os.path.join(output_directory, fn)
+
+            cmd = ['ffmpeg', '-y',
+                   '-f', 'concat',
+                   '-safe', '0',
+                   '-i', fd.name,
+                   '-map_metadata', '-1',
+                   '-codec:a', 'libmp3lame']
+            if vbr:
+                cmd.extend(['-codec:a', 'libmp3lame', '-q:a', '4'])
+            else:
+                cmd.extend(['-codec:a', 'copy'])
+            cmd.append(output)
+
+            p = subprocess.run(cmd, capture_output=False)
+            if p.returncode != 0:
+                print(f'error: ffmpeg returned {p.returncode}')
+            else:
+                success = True
+        finally:
+            os.unlink(fd.name)
+
+        if success and delete_source_files:
+            for file in g:
+                os.unlink(file['filename'])
+
+
+def main():
+    default_dir = os.getcwd()
+
+    parser = ArgumentParser()
+    parser.add_argument('--input-directory', '-i', type=str, default=default_dir,
+                        help='Directory with files')
+    parser.add_argument('--output-directory', '-o', type=str, default=default_dir,
+                        help='Output directory')
+    parser.add_argument('-D', '--delete-source-files', action='store_true')
+    parser.add_argument('--vbr', action='store_true',
+                        help='Re-encode using VBR (-q:a 4)')
+    args = parser.parse_args()
+
+    files = get_files(os.path.realpath(args.input_directory))
+    if not len(files):
+        print(f"No mp3 files found in {args.input_directory}.")
+        sys.exit()
+
+    groups = group_files(files)
+
+    merge(groups,
+          os.path.realpath(args.output_directory),
+          delete_source_files=args.delete_source_files,
+          vbr=args.vbr)
+
+
+if __name__ == '__main__':
+    main()