Add ffmpegtools.py.

voussoirkit/ffmpegtools.py

@@ -0,0 +1,45 @@
+import subprocess
+import os
+import tempfile
+
+from voussoirkit import pathclass
+
+def concatenate(input_files, output_file):
+    '''
+    Conveniently runs `ffmpeg -f concat` via subprocess.
+    '''
+    if len(input_files) < 2:
+        raise ValueError('Only one input file.')
+
+    input_files = [pathclass.Path(f) for f in input_files]
+
+    for file in input_files:
+        file.assert_is_file()
+
+    output_file = pathclass.Path(output_file)
+
+    names = [f.absolute_path for f in input_files]
+    names = [name.replace("'", "'\\''") for name in names]
+    cat_lines = [f'file \'{x}\'' for x in names]
+    cat_text = '\n'.join(cat_lines)
+    cat_file = tempfile.TemporaryFile('w', encoding='utf-8', delete=False)
+    cat_file.write(cat_text)
+    cat_file.close()
+
+    command = [
+        'ffmpeg',
+        '-f', 'concat',
+        '-safe', '0',
+        '-i', cat_file.name,
+        '-map', '0:v?',
+        '-map', '0:a?',
+        '-map', '0:s?',
+        '-c', 'copy',
+        output_file.absolute_path,
+    ]
+
+    subprocess.check_call(command)
+
+    os.remove(cat_file.name)
+
+    return output_file