subed

subed is an Emacs major mode for editing subtitles while playing the corresponding media file with mpv. At the moment, the only supported formats are:

• SubRip ( .srt)
• WebVTT ( .vtt )
• Advanced SubStation Alpha ( .ass, experimental )
• Tab-separated values ( .tsv, experimental ) - as exported by Audacity for labels. TSVs are not recognized automatically because it’s a common data format, but you can use subed-tsv-mode to turn it on in a buffer.

Features

• Jump to next (M-n) and previous (M-p) subtitle text.
• Jump to the beginning (C-M-a) and end (C-M-e) of the current subtitle’s text.
• Merge subtitles with M-m (subed-merge-dwim) and split them with M-. (subed-split-subtitle). If the media file is playing in MPV, use the current playback position. If not, use the relative position in the subtitle text, or other functions listed in subed-split-subtitle-timestamp-functions.
• Insert subtitles evenly spaced throughout the available space (M-i) or right next to the current subtitle (C-M-i). A prefix argument controls how many subtitles to insert and whether they are inserted before or after the current subtitle.
• Kill subtitles (M-k).
• Adjust subtitle start (M-[ / M-] or C-M-[ / C-M-] if Emacs lives in a terminal) and stop (M-{ / M-}) time. A prefix argument sets the number of milliseconds for the current session (e.g. C-u 1000 M-[ M-[ M-[ decreases start time by 3 seconds).
• Move the current subtitle or all marked subtitles (subed-move-subtitles) forward (C-M-n) or backward (C-M-p) in time without changing subtitle duration. A prefix argument sets the number of milliseconds for the current session (e.g. C-u 500 C-M-n C-M-n moves the current subtitle 1 second forward).
• Shift the current subtitle together with all following subtitles using (subed-shift-subtitles), or shift them forward (C-M-f) or backward (C-M-b). This is basically a convenience shortcut for C-SPC M-> C-M-n/p. This is handy for correcting sync delays where the subtitles are correctly spaced but are offset from the audio.
• Scale all subtitles or all marked subtitles forward (C-M-x) or backward (C-M-S-x) in time without changing subtitle duration. A prefix argument sets the number of milliseconds for the current session (e.g. C-u 500 C-M-x moves the last [or last marked] subtitle forward 500ms and proportionally scales all [or all marked] subtitles based on this time extension. Similarly, C-u 500 C-M-S-x moves the last [or last marked] subtitle backward 500ms and proportionally scales all [or all marked] subtitles based on this time contraction). This can be extremely useful to correct synchronization issues in existing subtitle files. First, adjust the starting time if necessary (e.g. C-M-f), then adjust the ending and scale constituent subtitles (e.g. C-M-x).
• Show CPS (characters per second) for the current subtitle.
• Insert HTML-like tags (C-c C-t C-t, with an optional attribute when prefixed by C-u), in particular italics (C-c C-t C-i) or boldface (C-c C-t C-b).
• SRT: Sort and re-number subtitles and remove any extra spaces and newlines (M-s). This is done automatically every time the buffer is saved.
• Trim subtitle overlaps with M-x subed-trim-overlaps. By default, this adjusts the stop time of overlapping subtitles to subed-subtitle-spacing milliseconds before the next subtitle starts. Use M-x customize-group subed to configure trimming to happen automatically when buffers are loaded or saved, which time is adjusted, and how much time to leave between subtitles.
• Convert between formats with M-x subed-convert.
• Show the waveform (M-x subed-waveform-minor-mode, off by default) extracted from the media file using ffmpeg with the start/stop positions of the current subtitle and the current position in MPV marked along with the subtitle. Change the “volume” of the waveform (i.e., the visible amplitude) with C-c C-- and C-c C-=. Redisplay the waveform with C-c |. Left/right-click on the waveform to set the start/stop timestamps. If you would like to display the waveform automatically when you open a file, you can add (add-hook 'subed-mode-hook 'subed-waveform-minor-mode) to your configuration.
• Load word timing data (ex: SRV2) using M-x subed-word-data-load-from-file. This will be used for splitting words at timestamps when available.
• Use M-x subed-align and aeneas to align your text or subtitles with an audio file in order to get timestamps.

mpv integration (optional)

Using network sockets to control MPV works on Linux and on Mac OS X, but not on Microsoft Windows due to the lack of Unix-style sockets. On Microsoft Windows, you will not be able to synchronize with MPV.

• Automatically open the associated media file in MPV based on the filename, open a media file manually with C-c C-v (subed-mpv-play-from-file), or play media directly from a URL with C-c C-u (subed-mpv-play-from-url) . You can customize the automatic detection of files by changing subed-video-extensions and subed-audio-extensions.
• Pause and resume playback without leaving Emacs (M-SPC).
• Jump to the current subtitle in the MPV player with M-j (subed-mpv-jump-to-current-subtitle). Toggle looping over the current subtitle with C-c C-l (subed-toggle-loop-over-current-subtitle). Control how many seconds to loop before or after the current subtitles by customizing subed-loop-seconds-before and subed-loop-seconds-after.
• Use C-c . (subed-toggle-sync-point-to-player) to toggle whether the point should move to the currently playing subtitle.
• Use C-c , (subed-toggle-sync-player-to-point) to toggle whether mpv should seek to the position of the current subtitle when the point moves between subtitles.
• Subtitles are automatically reloaded in mpv when the buffer is saved.
• Copy the current playback position as start (C-c [) or stop (C-c ]) time of the current subtitle.
• Playback is paused or slowed down when a subtitle’s text is edited (C-c C-p, subed-toggle-pause-while-typing).
• Loop over the current subtitle in mpv (C-c C-l).
• When a subtitle’s start or stop time changes, mpv seeks to the subtitle’s start time (C-c C-r, subed-toggle-replay-adjusted-subtitle).
• Move one frame forward or backward (C-c C-f . and C-c C-f ,; pressing , or . afterwards moves by frames until any other key is pressed).

Installation

Installing the subed package from NonGNU Elpa

subed is now on NonGNU ELPA. On Emacs 28 and later, you can install it with M-x package-install subed.

To install it on Emacs 27 or earlier, add the following to your Emacs configuration file:

(with-eval-after-load 'package (add-to-list 'package-archives '("nongnu" . "https://elpa.nongnu.org/nongnu/")))

Use M-x eval-buffer to run the code, use M-x package-refresh-contents to load the package archives, and then use M-x package-install subed.

Sample configuration:

(with-eval-after-load 'subed-mode
	;; Remember cursor position between sessions
	(add-hook 'subed-mode-hook 'save-place-local-mode)
	;; Break lines automatically while typing
	(add-hook 'subed-mode-hook 'turn-on-auto-fill)
	;; Break lines at 40 characters
	(add-hook 'subed-mode-hook (lambda () (setq-local fill-column 40)))
	;; Some reasonable defaults
	(add-hook 'subed-mode-hook 'subed-enable-pause-while-typing)
	;; As the player moves, update the point to show the current subtitle
	(add-hook 'subed-mode-hook 'subed-enable-sync-point-to-player)
	;; As your point moves in Emacs, update the player to start at the current subtitle
	(add-hook 'subed-mode-hook 'subed-enable-sync-player-to-point)
	;; Replay subtitles as you adjust their start or stop time with M-[, M-], M-{, or M-}
	(add-hook 'subed-mode-hook 'subed-enable-replay-adjusted-subtitle)
	;; Loop over subtitles
	(add-hook 'subed-mode-hook 'subed-enable-loop-over-current-subtitle)
	;; Show characters per second
	(add-hook 'subed-mode-hook 'subed-enable-show-cps))

Manual installation

If that doesn’t work, you can install it manually. To install from the main branch:

git clone https://github.com/sachac/subed.git

This will create a subed directory with the code.

If you have the make utility, you can regenerate the autoload definitions with

make autoloads

If you don’t have make installed, you can generate the autoloads with:

emacs --quick --batch --eval "(progn (setq generated-autoload-file (expand-file-name \"subed-autoloads.el\" \"subed\") backup-inhibited t) \
	(update-directory-autoloads \"./subed\"))"

Then you can add the following to your Emacs configuration (typically ~/.config/emacs/init.el, ~/.emacs.d/init.el, or ~/.emacs; you can create this file if it doesn’t exist yet). Here’s a configuration example:

;; Note the reference to the subed subdirectory, instead of the one at the root of the checkout
(add-to-list 'load-path "/path/to/subed/subed")
(require 'subed-autoloads)

(with-eval-after-load 'subed-mode
	;; Remember cursor position between sessions
	(add-hook 'subed-mode-hook 'save-place-local-mode)
	;; Break lines automatically while typing
	(add-hook 'subed-mode-hook 'turn-on-auto-fill)
	;; Break lines at 40 characters
	(add-hook 'subed-mode-hook (lambda () (setq-local fill-column 40)))
	;; Some reasonable defaults
	(add-hook 'subed-mode-hook 'subed-enable-pause-while-typing)
	;; As the player moves, update the point to show the current subtitle
	(add-hook 'subed-mode-hook 'subed-enable-sync-point-to-player)
	;; As your point moves in Emacs, update the player to start at the current subtitle
	(add-hook 'subed-mode-hook 'subed-enable-sync-player-to-point)
	;; Replay subtitles as you adjust their start or stop time with M-[, M-], M-{, or M-}
	(add-hook 'subed-mode-hook 'subed-enable-replay-adjusted-subtitle)
	;; Loop over subtitles
	(add-hook 'subed-mode-hook 'subed-enable-loop-over-current-subtitle)
	;; Show characters per second
	(add-hook 'subed-mode-hook 'subed-enable-show-cps))

You can reload your configuration with M-x eval-buffer or restart Emacs.

If you want to try a branch (ex: derived-mode), you can use the following command inside the subed directory:

git checkout branchname

use-package configuration

Here’s an example setup if you use use-package:

(use-package subed
	:ensure t
	:config
	;; Remember cursor position between sessions
	(add-hook 'subed-mode-hook 'save-place-local-mode)
	;; Break lines automatically while typing
	(add-hook 'subed-mode-hook 'turn-on-auto-fill)
	;; Break lines at 40 characters
	(add-hook 'subed-mode-hook (lambda () (setq-local fill-column 40)))
	;; Some reasonable defaults
	(add-hook 'subed-mode-hook 'subed-enable-pause-while-typing)
	;; As the player moves, update the point to show the current subtitle
	(add-hook 'subed-mode-hook 'subed-enable-sync-point-to-player)
	;; As your point moves in Emacs, update the player to start at the current subtitle
	(add-hook 'subed-mode-hook 'subed-enable-sync-player-to-point)
	;; Replay subtitles as you adjust their start or stop time with M-[, M-], M-{, or M-}
	(add-hook 'subed-mode-hook 'subed-enable-replay-adjusted-subtitle)
	;; Loop over subtitles
	(add-hook 'subed-mode-hook 'subed-enable-loop-over-current-subtitle)
	;; Show characters per second
	(add-hook 'subed-mode-hook 'subed-enable-show-cps)
	)

straight configuration

If you use straight.el, you can install subed with the following recipe:

(straight-use-package '(subed :type git :host github :repo "sachac/subed" :files ("subed/*.el")))

Getting started

C-h f subed-mode should get you started. This is the parent mode for subed-srt-mode, subed-vtt-mode, and subed-ass-mode. When manually loading a mode, use those specific format modes instead of subed-mode.

Some workflow ideas

Reflowing subtitles into shorter or longer lines

You may want to use set-fill-column and display-fill-column-indicator-mode to show the target number of characters.

Use subed-split-subtitle (M-.), subed-merge-dwim (M-b), and subed-merge-with-previous (M-M) to split lines.

Splitting will use the current MPV position if available. If not, it will guess where to split based on the the number of characters in the subtitle. You can use subed-mpv-jump-to-current-subtitle (M-j) to play the current subtitle manually and use subed-mpv-toggle-pause (M-SPC) to stop at the right time. Use subed-toggle-loop-over-current-subtitle (C-c C-l) if you want to keep looping. subed-waveform-show-current can help you fine-tune the split.

Adjusting timestamps

You can use subed-mpv-jump-to-current-subtitle (M-j) to play the current subtitle manually. Use subed-mpv-jump-to-current-subtitle-near-end (M-J) to jump to near the end of the subtitle in order to test it. Use subed-toggle-loop-over-current-subtitle (C-c C-l) if you want to keep looping automatically. Use subed-mpv-toggle-pause (M-SPC) to stop at the right time.

subed-waveform-show-current or subed-waveform-show-all can be useful for adjusting start and end timestamps. Use subed-waveform-set-start (mouse-1, which is left click) or subed-waveform-set-stop (mouse-3, which is right-click) to adjust only the current subtitle’s timestamps, or use subed-waveform-set-start-and-copy-to-previous (S-mouse-1 or M-mouse-1) or subed-waveform-set-stop-and-copy-to-next (S-mouse-3 or M-mouse-3) to adjust adjacent subtitles as well.

You can also manually adjust

• subtitle start: M-[ / M-]
• subtitle stop: (M-{ / M-})

A prefix argument sets the number of milliseconds (e.g. C-u 1000 M-[ M-[ M-[ decreases start time by 3 seconds).

Editing subtitles

You can use subed-mpv-jump-to-current-subtitle (M-j) to play the current subtitle and use subed-mpv-toggle-pause (M-SPC) to stop at the right time. Use subed-toggle-loop-over-current-subtitle (C-c C-l) if you want to keep looping automatically.

If you have wdiff installed, you can use subed-wdiff-subtitle-text-with-file to compare the subtitle text with a script or another subtitle file.

Writing subtitles from scratch

One way is to start with one big subtitle that covers the whole media file, and then split it using subed-split-subtitle (M-.).

Another way is to type as much of the text as you can without worrying about timestamps, putting each caption on a separate line. Then you can use subed-align to convert it into timestamped captions.

Timing / resynchronizing subtitles

If you’re using subed-waveform-show-current or subed-waveform-show-all, you can use M-mouse-2 (Meta-middle-click, subed-waveform-shift-subtitles) to shift the current subtitle and succeeding subtitles so that they start at the position you clicked on.

To do this with the keyboard, you can use subed-shift-subtitles-to-start-at-timestamp if you want to specify a timestamp or subed-shift-subtitles to specify a millisecond offset.

To use word timing data from something like WhisperX, load subed-word-data.el and then use subed-word-data-load-from-file. The word times will then be used when you split subtitles with subed-split-subtitle.

Rodrigo Morales also has some functions for playing part of the subtitles and changing them by a little bit.

Exporting text for review

You can use subed-copy-region-text to copy the text of the subtitles for pasting into another buffer. Call it with the universal prefix C-u to copy comments as well.

Troubleshooting

subed-mpv: Service name too long

If subed-mpv-client reports (error "Service name too long"), this is probably because the path to the socket used to communicate with MPV is too long for your operating system. You can use M-x customize to set subed-mpv-socket-dir to a shorter path.

Important change in v1.0.0

subed now uses subed-srt-mode, subed-vtt-mode, and subed-ass-mode instead of directly using subed-mode. These modes should be automatically associated with the .vtt, .srt, and .ass extensions. If the generic subed-mode is loaded instead of the format-specific mode, you may get an error such as:

Error in post-command-hook (subed--post-command-handler): (cl-no-applicable-method subed--subtitle-id)

If you set auto-mode-alist manually in your config, please make sure you associate extensions the appropriate format-specific mode instead of subed-mode. The specific backend functions (ex: subed-srt--jump-to-subtitle-id) are also deprecated in favor of using generic functions such as subed-jump-to-subtitle-id.

Testing

You’ll need to install the buttercup and package-lint Emacs packages. You’ll also need GNU Make so that you can work with Makefiles. To run the tests, use the command make test.

Contributions

Contributions would be really appreciated! subed conforms to the REUSE Specification; this means that every file has copyright and license information. If you modify a file, please update the year shown after SPDX-FileCopyrightText. Thank you!

There’s a list of authors in the file AUTHORS.org. If you have at any point contributed to subed, you are most welcome to add your name (and email address if you like) to the list.

License

subed is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

Build tips

Here’s a post-commit hook that will make it easier to remember to tag releases:

#!/usr/bin/python

# place in .git/hooks/post-commit
# Based on https://gist.github.com/ajmirsky/1245103

import subprocess
import re

print("checking for version change...",)

output = subprocess.check_output(['git', 'diff', 'HEAD^', 'HEAD', '-U0']).decode("utf-8")

version_info = None
for d in output.split("\n"):
    rg = re.compile(r'\+(?:;;\s+)?Version:\s+(?P<major>[0-9]+)\.(?P<minor>[0-9]+)\.(?P<rev>[0-9]+)')
    m = rg.search(d)
    if m:
        version_info = m.groupdict()
        break

if version_info:
    tag = "v%s.%s.%s" % (version_info['major'], version_info['minor'], version_info['rev'])
    existing = subprocess.check_output(['git', 'tag']).decode("utf-8").split("\n")
    if tag in existing:
        print("%s is already tagged, not updating" % tag)
    else:
        result = subprocess.run(['git', 'tag', '-f', tag])
        if result.returncode:
            raise Exception('tagging not successful: %s %s' % (result.stdout, result.returncode))
        print("tagged revision: %s" % tag)
else:
    print("none found.")

Other resources

• My subed customizations for editing captions of Emacsconf 2024 – Rodrigo Morales
• Sacha Chua’s subed-related blog posts
• Marcin Borkowski: 2023-09-18 Making Anki flashcards from subtitles
• sachac/subed-record: Record audio in segments and compile it into a file
• EmacsConf - Captioning tips