subtitles example with show progress

examples/subs.ass

@@ -0,0 +1,15 @@
+[Script Info]
+; Script generated by ass.py
+[V4+ Styles]
+Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
+Style: DEFAULT,arial,1,&HFE00FF00,&HFEFFFFFF,&HFE000000,&HFE0000FF,0,0,0,0,0,0,5,0.5,1,0,0,7,0,0,0,0
+[Events]
+Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
+Dialogue: 0,0:00:00.00,0:00:00.90,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}EIGHT
+Dialogue: 0,0:00:00.91,0:00:01.80,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}SEVEN
+Dialogue: 0,0:00:01.81,0:00:02.60,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}SIX
+Dialogue: 0,0:00:02.61,0:00:03.40,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}FIVE
+Dialogue: 0,0:00:03.41,0:00:04.30,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}FOUR
+Dialogue: 0,0:00:04.31,0:00:05.20,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}THREE
+Dialogue: 0,0:00:05.21,0:00:06.10,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}TWO
+Dialogue: 0,0:00:06.11,0:00:07.00,DEFAULT,HELLO,0,0,0,,{\pos(200,200)}{\fnArial}{\fs10}{\1c&H0000FF&}{\2c&HFFFF00&}{\3c&H000000&}{\4c&H000000&}{\K90}ONE

examples/subtitls_with_progress.py

@@ -0,0 +1,135 @@
+#!/usr/bin/env python
+from __future__ import unicode_literals, print_function
+from tqdm import tqdm
+import argparse
+import contextlib
+import ffmpeg
+import gevent
+import gevent.monkey; gevent.monkey.patch_all(thread=False)
+import os
+import shutil
+import socket
+import sys
+import tempfile
+import textwrap
+
+
+parser = argparse.ArgumentParser(description=textwrap.dedent('''\
+    Process video and report and show progress bar.
+
+    This is an example of using the ffmpeg `-progress` option with a
+    unix-domain socket to report progress in the form of a progress
+    bar.
+
+    The video processing simply consists of adding subbtitles using 
+    ASS templats but the same pattern can be applied to other use
+    cases.
+'''))
+
+parser.add_argument('in_filename', help='Input filename')
+parser.add_argument('out_filename', help='Output filename')
+parser.add_argument('ass_filename', help='ASS subtitle template')
+
+
+@contextlib.contextmanager
+def _tmpdir_scope():
+    tmpdir = tempfile.mkdtemp()
+    try:
+        yield tmpdir
+    finally:
+        shutil.rmtree(tmpdir)
+
+
+def _do_watch_progress(filename, sock, handler):
+    """Function to run in a separate gevent greenlet to read progress
+    events from a unix-domain socket."""
+    connection, client_address = sock.accept()
+    data = b''
+    try:
+        while True:
+            more_data = connection.recv(16)
+            if not more_data:
+                break
+            data += more_data
+            lines = data.split(b'\n')
+            for line in lines[:-1]:
+                line = line.decode()
+                parts = line.split('=')
+                key = parts[0] if len(parts) > 0 else None
+                value = parts[1] if len(parts) > 1 else None
+                handler(key, value)
+            data = lines[-1]
+    finally:
+        connection.close()
+
+
+@contextlib.contextmanager
+def _watch_progress(handler):
+    """Context manager for creating a unix-domain socket and listen for
+    ffmpeg progress events.
+
+    The socket filename is yielded from the context manager and the
+    socket is closed when the context manager is exited.
+
+    Args:
+        handler: a function to be called when progress events are
+            received; receives a ``key`` argument and ``value``
+            argument. (The example ``show_progress`` below uses tqdm)
+
+    Yields:
+        socket_filename: the name of the socket file.
+    """
+    with _tmpdir_scope() as tmpdir:
+        socket_filename = os.path.join(tmpdir, 'sock')
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        with contextlib.closing(sock):
+            sock.bind(socket_filename)
+            sock.listen(1)
+            child = gevent.spawn(_do_watch_progress, socket_filename, sock, handler)
+            try:
+                yield socket_filename
+            except:
+                gevent.kill(child)
+                raise
+
+
+
+@contextlib.contextmanager
+def show_progress(total_duration):
+    """Create a unix-domain socket to watch progress and render tqdm
+    progress bar."""
+    with tqdm(total=round(total_duration, 2)) as bar:
+        def handler(key, value):
+            if key == 'out_time_ms':
+                time = round(float(value) / 1000000., 2)
+                bar.update(time - bar.n)
+            elif key == 'progress' and value == 'end':
+                bar.update(bar.total - bar.n)
+        with _watch_progress(handler) as socket_filename:
+            yield socket_filename
+
+
+if __name__ == '__main__':
+    args = parser.parse_args()
+    try:
+        probe = ffmpeg.probe(args.in_filename)
+        total_duration = float(probe['format']['duration'])
+    except ffmpeg.Error as e:
+        print('stdout:', e.stdout.decode('utf8'))
+        print('stderr:', e.stderr.decode('utf8'))
+        raise e
+
+    with show_progress(total_duration) as socket_filename:
+        try:
+            (ffmpeg
+                .input(args.in_filename)
+                .filter("subtitles", args.ass_filename)
+                .output(args.out_filename)
+                .global_args('-progress', 'unix://{}'.format(socket_filename))
+                .overwrite_output()
+                .run(capture_stdout=True, capture_stderr=True)
+            )
+        except ffmpeg.Error as e:
+            print(e.stderr, file=sys.stderr)
+            sys.exit(1)
+