Manually transcribe

Either subtitles (with timestamps) or a text transcript (no timestamps) is perfectly okay.

  • ☐ mplsCorwin: emacsconf-2020–03-idea-to-novel-superstructure-emacs-for-writing–questions–bala-ramadurai.webm
  • ☐ mplsCorwin: emacsconf-2020–08-building-reproducible-emacs–andrew-tropin.webm
  • ☑ sachac: emacsconf-2020–10-lead-your-future-with-org–andrea.webm Added transcript to info/10.md, seeing if YouTube can automatically assign timing. Took about 24 minutes to transcribe 8 minute talk. If it doesn't work out, I might manually time it. … It worked!
  • ☐ zaeph: emacsconf-2020–24-analyze-code-quality-through-emacs-a-smart-forensics-approach-and-the-story-of-a-hack–andrea.webm

Edit automatic subtitles

To reduce duplication of work, make sure you have the latest copy of organizers-notebook.org. Mark the one you want to do by prepending your name to the TODO title, and commit organizers-notebook.org back to the repo.

I modified the subed package to work with VTT files. The modified version is at https://github.com/sachac/subed/tree/subed-vtt , and I've submitted a pull request. It's pretty cool! If you copy the webm to the same directory and name it with the same filename (except ending in .webm instead of .vtt, of course), subed will automatically synchronize as you move through the subtitles. Demo

  • ☐ <./subtitles/emacsconf-2020--00-opening-remarks-autogen.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--03-idea-to-novel-superstructure-emacs-for-writing--bala-ramadurai-autogen.vtt> See <info/03/screenplay.fountain>
  • ☑ sachac <./subtitles/emacsconf-2020--04-music-in-plain-text--jonathan-gregory.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--05-bard-bivoumacs-building-a-bandcamp-like-page-for-an-album-of-music--grant-shangreaux.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--05-bard-bivoumacs-building-a-bandcamp-like-page-for-an-album-of-music--questions--grant-shangreaux.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--07-beyond-vim-and-emacs-a-scalable-ui-paradigm--questions--sid-kasivajhula.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--07-beyond-vim-and-emacs-a-scalable-ui-paradigm--sid-kasivajhula.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--09-orgmode-your-life-in-plain-text--rainer-koenig.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--11-the-org-gtd-package-opinions-about-getting-things-done--aldric.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--12-one-big-ass-org-file-or-multiple-tiny-ones-finally-the-end-of-the-debate--leo-vivier-autogen.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--13-experience-report-steps-to-emacs-hyper-notebooks--joseph-corneli-raymond-puzio-cameron-ray-smith-autogen.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--14-readme-driven-design--adam-ard-autogen.vtt>
  • ☑ sachac <./subtitles/emacsconf-2020--15-moving-from-jekyll-to-orgmode-an-experience-report--adolfo-villafiorita-autogen.vtt>
  • ☑ sachac <./info/16.md> <./subtitles/emacsconf-2020--16-org-roam-presentation-demonstration-and-whats-on-the-horizon--leo-vivier.vtt>
  • ☑ sachac <./info/17.md> <./subtitles/emacsconf-2020--17-org-mode-and-org-roam-for-scholars-and-researchers--noorah-alhasan.vtt>
  • ☑ sachac <./info/18.md> <./subtitles/emacsconf-2020--18-org-roam-technical-presentation--leo-vivier.vtt>
  • ☑ sachac <./info/19.md> <./subtitles/emacsconf-2020--19-sharing-blogs-and-more-with-org-webring--brett-gilio-autogen.vtt>
  • ☑ sachac <./info/20.md> <./subtitles/emacsconf-2020--20-omg-macros--corwin-brust-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--21-on-why-most-of-the-best-features-in-eev-look-like-5-minute-hacks--eduardo-ochs-autogen.vtt>
  • ☐ sachac <./subtitles/emacsconf-2020--22-powering-up-special-blocks--musa-al-hassy-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--23-incremental-parsing-with-emacs-tree-sitter--questions--tuan-anh-nguyen-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--23-incremental-parsing-with-emacs-tree-sitter--tuan-anh-nguyen-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--25-traverse-complex-json-structures-with-live-feedback-counsel-jq--zen-monk-alain-m-lafon-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--26-emacs-as-a-highschooler-how-it-changed-my-life--pierce-wang-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--26-emacs-as-a-highschooler-how-it-changed-my-life--questions--pierce-wang-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8--vasilij-wasamasa-schneidermann-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--28-welcome-to-the-dungeon--erik-elmshauser-corwin-brust-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--30-a-tour-of-vterm--gabriele-bozzola-sbozzolo-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--30-a-tour-of-vterm--questions--gabriele-bozzola-sbozzolo-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--31-lakota-language-and-emacs--grant-shangreaux-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--31-lakota-language-and-emacs--questions--grant-shangreaux-autogen.vtt>
  • ☐ bhavin192 <./subtitles/emacsconf-2020--32-object-oriented-code-in-the-gnus-newsreader--eric-abrahamsen-autogen.vtt>
  • ☐ bhavin192 <./subtitles/emacsconf-2020--33-maxima-a-computer-algebra-system-in-emacs--fermin.vtt>
  • ☐ bhavin192 <./subtitles/emacsconf-2020--34-extend-emacs-to-modern-gui-applications-with-eaf--matthew-zeng-autogen.vtt>
  • ☑ bhavin192 <./info/35.md> <./subtitles/emacsconf-2020--35-waveing-at-repetitive-repetitive-repetitive-music-zmusic--zachary-kanfer-autogen.vtt>
  • ☑ bhavin192 <./info/35.md> <./subtitles/emacsconf-2020--35-waveing-at-repetitive-repetitive-repetitive-music-zmusic--questions--zachary-kanfer-autogen.vtt>
  • ☑ bhavin192 <./info/38.md> <./subtitles/emacsconf-2020--38-emacs-development-update--john-wiegley.vtt>
  • ☑ bhavin192 <./info/39.md> <./subtitles/emacsconf-2020--39-nongnu-elpa--questions--richard-stallman.vtt>
  • ☑ bhavin192 <./info/39.md> <./subtitles/emacsconf-2020--39-nongnu-elpa--richard-stallman.vtt>
  • ☐ <./subtitles/emacsconf-2020--40-closing-remarks-part-1-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--40-closing-remarks-part-2-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--41-opening-remarks-autogen.vtt>
  • ☐ <./subtitles/emacsconf-2020--42-closing-remarks-autogen.vtt>

Assumptions and settings

Note that re-evaluating a defvar won't change the value, so if you want to change the value after this is already loaded, use (setq ...).

(defvar conf/year 2020 "Year of conference.")
(defvar conf/buffer-minutes 3 "Number of minutes to use as a buffer between talks.")
(defvar conf/timezones '("EST" "America/Los_Angeles" "UTC" "CET" "Asia/Singapore") "List of timezones")
(defvar conf/autogenerate-talk-pages nil "Set this to t at the beginning of the conference, when we're still autogenerating individual talk pages.
Otherwise you might overwrite hand-edited talk pages.")
(defvar conf/collaborative-pad "https://etherpad.wikimedia.org/p/emacsconf-2020" "URL of collaborative pad.")
(defvar conf/streaming-nick "bandali" "IRC nick of main organizer in charge of streaming.")
(defvar conf/topic-templates nil "List of (channel topic-template) entries for mass-setting channel topics.")
(defvar conf/rooms '(("A" "http://example.org?room=a")
                     ("B" "http://example.org?room=b")
                     ("C" "http://example.org?room=c")) 
  "List of (code join-url) entries. Room codes should be uppercase.") ; actually set this in organizers' wiki index.org
(setq conf/topic-templates 
      '(("#emacsconf" "EmacsConf 2020 is over, thanks for joining! | Subscribe to https://lists.gnu.org/mailman/listinfo/emacsconf-discuss for updates")
        ("#emacsconf-accessible" "EmacsConf 2020 is over. Thanks for making it more accessible! | Subscribe to https://lists.gnu.org/mailman/listinfo/emacsconf-discuss for updates")
        ("#emacsconf-org" "EmacsConf2020 is over, thanks for joining! | Dedicated channel for EmacsConf organizers and speakers | this is intended as an internal, low-traffic channel; for main discussion around EmacsConf, please join #emacsconf | Subscribe to https://lists.gnu.org/mailman/listinfo/emacsconf-discuss for updates")))


STREAM - main organizer, CHECK - secondary organizer or volunteer, PAD - organizer focusing on pad


  • Collect e-mail addresses of accepted speakers into a list for easy pasting into Bcc (organizers' private wiki)
  • See submissions.org for Org scheduling code; 3 minutes of buffer was okay last time, but more would be better for Q&A; opening remarks time could be trimmed

Code for scheduling

(defun conf/get-talk-info ()
  (let (talk results)
    (org-map-entries (lambda ()
                       (let ((heading (org-heading-components)))
                          ((and (elt heading 2) (or (null talk)
                                                    (<= (car heading)
                                                        (plist-get talk :level)))) ;; has a todo, therefore is a talk
                           (when talk (setq results (cons talk results)))
                           (setq talk (list
                                       :type 'talk
                                       :title (elt heading 4)
                                       :talk-id (org-entry-get (point) "TALK_ID")
                                       :status (elt heading 2)
                                       :level (car heading)
                                       :scheduled (org-entry-get (point) "SCHEDULED")
                                       :duration (org-entry-get (point) "DURATION")
                                       :time (org-entry-get (point) "MIN_TIME")
                                       :speakers (org-entry-get (point) "NAME"))))
                          ((string-match "^ *Talk information *$" (elt heading 4))
                           (plist-put talk :info
                                      (org-export-as 'md t nil t)))
                          ((or (null talk) (< (car heading) (plist-get talk :level)))  ;; heading above
                           (when talk
                             (setq results (cons talk results))
                             (setq talk nil))
                           (setq results (cons
                                          (list :type 'headline
                                                :level (car heading)
                                                :speakers (org-entry-get (point) "NAME")
                                                :duration (org-entry-get (point) "DURATION")
                                                :talk-id (org-entry-get (point) "TALK_ID")
                                                :title (elt heading 4)
                                                :scheduled (org-entry-get (point) "SCHEDULED"))
                     nil 'tree)
    (when talk (setq results (cons talk results)))
    (reverse results)))

(defun conf/filter-talks (list)
  "Return only talk info in LIST."
   (lambda (talk) (eq (plist-get talk :type) 'talk))

(defun conf/get-talk-info-from-file (&optional filename)
    (insert-file-contents (or filename "submissions.org"))
    (goto-char (point-min))
    (goto-char (org-find-property "ID" "talks"))

(defun conf/find-talk (filter &optional info)
  (setq info (or info (conf/filter-talks conf/info)))
  (when (stringp filter) (setq filter (list filter)))
  (or (seq-find (lambda (o) (string= (plist-get o :talk-id) (car filter))) info)
      (seq-find (lambda (o)
                  (let ((case-fold-search t)
                        (all (mapconcat (lambda (f) (plist-get o f)) '(:title :speakers :talk-id) " ")))
                    (null (seq-contains-p
                           (mapcar (lambda (condition) (string-match condition all)) filter)

(defun conf/goto-talk-id (id)
  (goto-char (org-find-property "TALK_ID" id)))

(defun conf/assign-ids ()
  "Assign numeric talk IDs."
  (goto-char (point-min))
  ;; Determine the maximum ID assigned so far
  (let ((id
          (apply 'max
                 (or (mapcar
                       (lambda ()
                         (let ((org-trust-scanner-tags t))
                           (org-entry-get (point) "TALK_ID"))) "TALK_ID>0" 'file))
    (goto-char (point-min))
    (while (re-search-forward "^ *:NAME: " nil t)
      (unless (org-entry-get (point) "TALK_ID")
        (org-set-property "TALK_ID" (format "%02d" id))
        (org-set-property "CUSTOM_ID" (format "talk%02d" id))
        (setq id (1+ id))))))

(defun conf/update-talks ()
  "Update times, tables, and schedules."

(defun conf/update-times ()
  "Check whether we need more time or less time based on TARGET_TIME and MIN_TIME_SUM."
  (goto-char (point-min))
   (lambda ()
     (when (org-entry-get (point) "TARGET_TIME")
        (let ((diff
                (string-to-number (org-entry-get (point) "TARGET_TIME"))
                (string-to-number (org-entry-get (point) "MIN_TIME_SUM")))))
           ((> diff 0) (format "Extra: %d" diff))
           ((< diff 0) (format "Needs: %d" (- diff)))
           (t "")))))) nil 'file))

(defun conf/update-tables ()
  "Update the time checks and table reports."
  (goto-char (point-min))
  (while (re-search-forward "#\\+CALL: check_time()" nil t)
  (goto-char (point-min))
  (while (re-search-forward "#\\+BEGIN: columnview" nil t)

(defun conf/update-schedules ()
  "Schedule the talks based on the MIN_TIME and 3 minutes of buffer.
Talks with a FIXED_TIME property are not moved."
  (goto-char (org-find-exact-headline-in-buffer "Talks"))
  (let (current-time scheduled end-time duration (buffer (seconds-to-time (* conf/buffer-minutes 60))))  ;; assumption: 3 minutes between talks
    (org-map-entries (lambda ()
                       (if (org-entry-get (point) "FIXED_TIME")
                           (setq current-time (org-get-scheduled-time (point))))
                       (when (org-entry-get (point) "MIN_TIME")
                         (setq duration (* (string-to-number (org-entry-get (point) "MIN_TIME")) 60)
                               end-time (time-add current-time (seconds-to-time duration)))
                         (org-set-property "SCHEDULED" (format "%s-%s" (org-format-time-string "%Y-%m-%d %H:%M" current-time)
                                                               (org-format-time-string "%H:%M" end-time)))
                         (setq current-time (time-add end-time buffer))))
                     nil 'tree)))

(defun conf/org-sum-min-time-in-subtree ()
  "Add up all the MIN_TIME properties of headings underneath the current one
The total is written to the MIN_TIME_SUM property of this heading"
     (format "%d"
              (mapcar 'string-to-number
                      (delq nil
                             (lambda () (org-entry-get (point) "MIN_TIME")) nil 'tree))))))))

Generate schedule file

(defun conf/format-talk-link (talk)
  (and talk (if (plist-get talk :talk-id)
                (format "<a href=\"/%d/talks/%s\">%s</a>"
                        (plist-get talk :talk-id)
                        (plist-get talk :title))
              (plist-get talk :title))))

(defun conf/format-talk-info-as-schedule (info)
  (format "<table width=\"100%%\">%s</table>"
           (lambda (o)
             (let* ((time-fmt "%l:%M %p")
                    (timestamp (org-timestamp-from-string (plist-get o :scheduled)))
                    (start (if timestamp (format-time-string time-fmt (org-timestamp-to-time (org-timestamp-split-range timestamp))) ""))
                    (end (if timestamp (format-time-string time-fmt (org-timestamp-to-time (org-timestamp-split-range timestamp t))) ""))
                    (title (plist-get o :title))
                    (speakers (plist-get o :speakers)))
               (if (eq (plist-get o :type) 'headline)
                   (format "<tr><td colspan=\"4\"><strong>%s<strong></td></tr>"
                           (if (plist-get o :talk-id)
                               (conf/format-talk-link o)
                 (format "<tr><td width=100>~%s</td><td width=100>~%s</td><td>%s</td><td>%s</td></tr>"
                         start end (conf/format-talk-link o) speakers))))
           (cdr info) "\n")))

(defun conf/filter-talks (info)
  (seq-filter (lambda (o) (plist-get o :talk-id)) info))

(defun conf/split-out-talk-information ()
  (let ((talks (conf/filter-talks conf/info)))
    (mapc (lambda (o)
               (format "# %s\n%s\n\n%s"
                       (plist-get o :title)
                       (plist-get o :speakers)
                       (plist-get o :info)))
              (write-file (expand-file-name (format "%s.md" (plist-get o :talk-id)) "info"))))

(defun conf/format-talk-pages (info)
  (let* ((talks (conf/filter-talks info))
         (next-talks (cdr talks))
         (prev-talks (cons nil talks)))
    (mapc (lambda (o)
              (let* ((timestamp (org-timestamp-from-string (plist-get o :scheduled)))
                     (next-talk (conf/format-talk-link (pop next-talks)))
                     (prev-talk (conf/format-talk-link (pop prev-talks)))
                     (schedule (mapconcat
                                (lambda (tz)
                                  (format "%s - %s"
                                          (format-time-string "%A, %b %e %Y, ~%l:%M %p"
                                                              (org-timestamp-to-time (org-timestamp-split-range timestamp)) tz)
                                          (format-time-string "%l:%M %p %Z"
                                                              (org-timestamp-to-time (org-timestamp-split-range timestamp t)) tz)))
                                "  \n"))
                     (nav-links (format "Back to the <a href="../schedule/">schedule</a>  \n%s%s"
                                        (if prev-talk (format "Previous: %s  \n" prev-talk) "")
                                        (if next-talk (format "Next: %s  \n" next-talk) ""))))
                (insert (format "<span class="createlink">&#37;s title&#61;&#92;&#34;&#37;s&#92;&#34;</span>
  <span class="createlink">&#37;s copyright&#61;&#92;&#34;Copyright &#38;copy&#59; &#37;s &#37;s&#92;&#34;</span>

  <!-- To edit the talk information, change info/TALKID.md. Boilerplate automatically generated from submissions.org using conf/generate-schedule-files --->\n


  [[!inline <span class="error">Error: syntax error in pagespec &quot;&#92;&quot;internal&#40;&#37;s/info/&#37;s&#41;&#92;&quot;&quot;</span>]]



                                (replace-regexp-in-string "\"" "\\\\\"" (plist-get o :title))
                                (plist-get o :speakers)
                                (plist-get o :talk-id)
              (write-file (format "talks/%s.md" (plist-get o :talk-id)))))

(defun conf/generate-pad-template ()
  "Generate a template for copying and pasting into the pad.
Writes it to pad-template.html."
  (interactive "p")
  (let* ((talks (conf/filter-talks conf/info))
         (text (concat
              "<p>Conference info, how to watch/participate: https://emacsconf.org/2020/<br />
Guidelines for conduct: https://emacsconf.org/conduct/</p>

<p>Except where otherwise noted, the material on the EmacsConf pad are dual-licensed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International Public License; and the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) an later version.
Copies of these two licenses are included in the EmacsConf wiki repository, in the COPYING.GPL and COPYING.CC-BY-SA files (https://emacsconf.org/COPYING/).</p>

<p>By contributing to this pad, you agree to make your contributions available under the above licenses. You are also promising that you are the author of your changes, or that you copied them from a work in the public domain or a work released under a free license that is compatible with the above two licenses. DO NOT SUBMIT COPYRIGHTED WORK WITHOUT PERMISSION.</p>

This pad is here to be curated by everybody and its rough structure is like this:
<ol><li>General info and license
<li>A section for each talk -> please do add questions and notes
<li>A general feedback section
        (lambda (o)
          (let ((url (format "https://emacsconf.org/%s/schedule/%s" conf/year (plist-get o :talk-id))))
            (format "-------------------------------------------------------------------------------------------------<br/><strong>Talk%s: %s</strong><br />
Speaker(s): %s<br />  
Talk page: <a href=\"%s\">%s</a><br />
Actual start of talk EST: &nbsp;&nbsp;&nbsp;  Start of Q&A: &nbsp;&nbsp;  End of Q&A: &nbsp;&nbsp;<br />
Speakers may answer in any order or skip questions. As much as possible, put your questions at the top level instead of under another question. If adding an answer, please indicate [speaker] or your nick accordingly. Volunteers, please add new slots as ones get filled.<br />

<strong>Links and other notes:</strong>
  <li>sample text</li>
  <li>sample text</li>
  <li>sample text</li>
  <li>sample text</li>
" (plist-get o :talk-id) (plist-get o :title) (plist-get o :speakers) url url))) talks "<br/><br/>\n") 
<strong>General Feedback: What went well?</strong><br/><br/>
  <li>sample text</li>
  <li>sample text</li>
  <li>sample text</li>
  <li>sample text</li>
<br /><br />
<strong>General Feedback: What to improve?</strong><br/><br/>
  <li>sample text</li>
  <li>sample text</li>
  <li>sample text</li>
  <li>sample text</li>
    (with-current-buffer (find-file "pad-template.html")
      (insert text)
  (browse-url-of-file "pad-template.html"))

(defun conf/generate-talks-page ()
  (let ((info conf/info))
      (find-file "talk-details.md")
      (insert (format "<table><thead><th>Duration</th><th>Title</th><th>Speakers</th></thead><tbody>%s</tbody></table>"
                       (lambda (o)
                         (let* ((title (plist-get o :title))
                                (speakers (plist-get o :speakers)))
                           (if (null (plist-get o :talk-id))
                               (format "<tr><td colspan=\"3\">%s</td></tr>" (conf/format-talk-link o))
                             (format "<tr><td>%s</td><td>%s</td><td>%s</td><tr>" 
                                     (plist-get o :duration)
                                     (conf/format-talk-link o)
                                     (plist-get o :speakers)))))
                       info "\n")))

(defun conf/generate-schedule-files (&optional filename)
    (insert (conf/format-talk-info-as-schedule conf/info))
    (write-file "schedule-details.md"))
  (when conf/autogenerate-talk-pages (conf/format-talk-pages conf/info)))

Set the info based on submissions.org.

(setq conf/info (conf/get-talk-info-from-file "submissions.org"))

Before the conference

  • Do tech checks and get alternative ways to contact speakers (phone number? IRC nick? Something that goes ding?)
  • Install Mute Tab extension if desired
  • Send encoding tips for prerecs
  • Normalize audio for prerecs
  • Ask speakers for prerecs, links, slides, other resources
  • Put prerecs in orga@front0:~/prerecs so that people can use mediainfo to check duration
  • Plan volunteer availability
  • Set up local icecast server and have live0 relay
  • Create individual talk pages and schedule.
  • Set up pad with Q1: Q2: Q3: Q4: slots: conf/generate-pad-template

Tech check

  • Explain process
  • Test audio, webcam, screensharing, collaborative pad
    • Music demos and other things that use system audio will need to be prerecorded (or done through virtual loopback device, maybe? Technical risk.)
    • Multi-monitor setups might not be handled well by BBB; share window instead of desktop
  • Check if comfortable checking into IRC: #emacsconf-org
  • Ask about Q&A preference; OR:
    • live Q&A
    • Q&A over pad or IRC
    • no Q&A
  • Get IRC nick and phone number for emergency contact, store in private wiki
  • Try to record name pronunciation
  • Encourage webcam for Q&A, although make it clear that it's totally optional
  • Possible picture-in-picture approach to maximize screen real estate
    • Linux: share desktop, run cheese, set Always on Top

During the conference

Start of streaming

  • STREAM starts streaming and has live0 relay
  • STREAM displays time on screen: watch TZ=America/New_York date ?
  • CHECK confirms stream and starts low-resolution mirror

ffmpeg: mirror main stream to low-resolution stream

Needs the $main480p environment variable set to somethnig of the form icecast://username:password@site:port/mount-point.webm. Icecast configuration can be found on live0 at /etc/icecast2/icecast.xml. It was okay to run this command directly on live0 in 2020, since that kept the speed at roughly 1x.

while true; do ffmpeg -f webm -reconnect_at_eof 1 -reconnect_streamed 1  -re -i http://localhost:8000/main.webm -vf scale=854:480 -f webm -c:a copy -b:v 500k -maxrate 1M -bufsize 1M  -content_type video/webm -c:v libvpx  $main480p done

Shortly before the presentation

  • Speaker checks in via IRC ~30m before
  • CHECK directs speaker to available room
  • Speaker joins talk room
  • CHECK makes speaker presenter and moderator, does last-minute tech check
    • Hello, thanks
    • Speaker tries screen sharing and webcam
    • check screen readability
    • CHECK briefs speaker on process, including:
      • confirming preferences:
        • prerec / live talk
        • live Q&A / IRC / no Q&A
        • live Q&A: reading questions themselves (can do in any order, can skip) or asking STREAM to read questions to them
      • encouragement of webcam, although it's optional
      • how STREAM will join and then give them the go-ahead
      • closing any tabs watching the stream as their talk starts (otherwise the audio is confusing)
      • starting with saying their name clearly and doing a quick intro to their talk
  • CHECK notifies STREAM with link to the talk room and preferences for prerec or live talk, live Q&A / IRC / no Q&A
  • STREAM joins meeting and gives go-ahead
  • CHECK starts recording in BBB
  • CHECK announces on IRC
  • PAD clears the pad colours and updates timestamp

During the presentation

  • OR:
    • Live presentation?
      • Speaker presents, keeping an eye on the collaborative pad for questions
      • STREAM stays with speaker to stream and to help with questions and timing
    • Prerecorded? STREAM plays prerecorded video on computer
    • Streamed live from somewhere else?
      • Make sure to have a separate way to communicate (ex: IRC)
  • OTHER keeps an eye on audio levels and tells STREAM if adjustments are needed
  • If there is another speaker, CHECK moves to next room for setup
  • OTHER moves past prerecs to public directory (maybe even current?)
    • (It would be pretty cool if we can figure out how to make the previous talks available for watching)


  • STREAM joins speaker's room if not already there
  • STREAM gives go-ahead to start Q&A
  • Speaker reads questions off the pad or gets questions from STREAM
  • Time is indicated by having an organizer type into the Etherpad, or speaking up if needed
  • If moderation is needed, organizers add a reminder that speakers can choose to skip questions or answer in any order
  • STREAM goes to next talk when ready

Lunch break

  • STREAM plays music
  • STREAM quickly highlights #emacsconf-accessible, Etherpad, notes


Prerecorded presentations

  • STREAM will play it on the computer and stream from there (or ideally, send it directly to the stream)

Tech issues

  • If can't be easily resolved, play pre-recorded talk early and try again later (or follow up)
  • Stream a technical issues slide to the end point

Code for ERC

Load data

(defvar conf/info nil "List of plists with the following keys: `:talk-id', `:name', `:speakers', and other info.") ; Set from submissions.org

Announce topics

(defmacro conf/erc-with-channels (channel-list &rest forms)
  (declare (indent 1) (debug (form form body)))
  `(mapcar (lambda (channel)
             (with-current-buffer (erc-get-buffer channel)

(defun conf/get-room (room)
  (cadr (assoc (upcase room) conf/rooms)))

(defun erc-cmd-CONFTOPIC (&rest message)
  "Set the topic to MESSAGE | template in the conference channels.
If MESSAGE is not specified, reset the topic to the template."
  (mapc (lambda (template) 
          (with-current-buffer (erc-get-buffer (car template))
            (erc-cmd-TOPIC (if message (concat (if (stringp message) message (s-join " " message)) " | " (cadr template))
                             (cadr template)))))

(defun erc-cmd-CHECKIN (room nick)
  "Send instructions for ROOM and `conf/collaborative-pad' to NICK."
  (let ((room-url (conf/get-room room)))
    (unless room-url (error "Please specify nick and room name"))
    (erc-send-message (format "%s: Thanks for checking in! I'll send you some private messages with the instructions for room %s, so please check there. (Let me know if you don't get them!)" nick
    (upcase room)))
    (erc-message "PRIVMSG" (format "%s You can use this BBB room for your presentation: %s . I'll join you there shortly to set up the room and do the last-minute tech check." nick room-url))
    (erc-message "PRIVMSG" (format "%s The collaborative pad we'll be using for questions is at %s . We'll collect questions from #emacsconf and put them there. If you'd like to jump to your part of the document, you might be able to keep an eye on questions. Alternatively, we can read questions to you." nick conf/collaborative-pad))
    (erc-message "PRIVMSG" (format "%s Amin will join when it's time for your presentation, and he will give you the go-ahead when it's time to present. See you in the BBB room!" nick))))

(defun erc-cmd-READY (code &rest filter)
  "Notify #emacsconf-org and `conf/streaming-nick' that CODE is ready for the talk specified by FILTER.
FILTER can be the talk ID or strings to match against the title or speaker names."
  (let ((room-url (conf/get-room code))
        (talk (conf/find-talk filter)))
    (unless room-url (error "Could not find room"))
    (unless talk (error "Could not find talk"))
    (with-current-buffer (erc-get-buffer "#emacsconf-org")
      (erc-send-message (format "Ready in Room %s: %s (%s)"
                                (upcase code)
                                (plist-get talk :title)
                                (plist-get talk :speakers))))
    (erc-message "PRIVMSG" 
                 (format "%s Ready in Room %s ( %s ): %s (%s)"
                         (upcase code)
                         (plist-get talk :title)
                         (plist-get talk :speakers)))))

(defun erc-cmd-ANNOUNCE (&rest filter)
  "Set the channel topics to announce the talk specified by FILTER.
FILTER can be the talk ID or strings to match against the title or speaker names."
  (let ((info (conf/find-talk filter)) message)
    (unless info (error "Could not find talk."))
    (erc-cmd-CONFTOPIC (format "talk%s: %s (%s)"
                               (plist-get info :talk-id)
                               (plist-get info :title)
                               (plist-get info :speakers)))))

(defun erc-cmd-BROADCAST (&rest message)
  "Say MESSAGE in all the conference channels."
  (conf/erc-with-channels (mapcar 'car conf/topic-templates)
                          (erc-send-message (s-join " " message))))

After the conference

Convert pad, copy sections to individual pages

This makes the links available right away

Split individual files

Post to individual pages, and make a talks page with durations. Change individual schedule pages to redirect to talks (or start there in the first place).

Announcement example: https://lists.gnu.org/r/emacsconf-discuss/2020-12/msg00000.html

Splitting up the stream recording into individual files

NOTE: ffmpeg has a hard time splitting with -c:v copy unless it's on a keyframe boundary. If it isn't on a keyframe, then you'll have a few seconds of black video until the next keyframe kicks in.

Here's an example of what we had for splitting.

ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss   13:04 -to   20:08    -c:a copy -c:v copy emacsconf-2020--00-opening-remarks.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss   27:24 -to   51:39    -c:a copy -c:v copy emacsconf-2020--03-an-emacs-developer-story-from-user-to-package-maintainer--leo-vivier.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 1:00:08 -to 1:09:22    -c:a copy -c:v copy emacsconf-2020--03-idea-to-novel-superstructure-emacs-for-writing--questions--bala-ramadurai.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 1:41:28 -to 1:55:13    -c:a copy -c:v copy emacsconf-2020--05-bard-bivoumacs-building-a-bandcamp-like-page-for-an-album-of-music--questions--grant-shangreaux.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 1:57:24 -to 2:11:05    -c:a copy -c:v copy emacsconf-2020--06-trivial-emacs-kits--corwin-brust.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 2:32:00 -to 2:36:35    -c:a copy -c:v copy emacsconf-2020--07-beyond-vim-and-emacs-a-scalable-ui-paradigm--questions--sid-kasivajhula.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 4:55:00 -to 5:11:38    -c:a copy -c:v copy emacsconf-2020--12-one-big-ass-org-file-or-multiple-tiny-ones-finally-the-end-of-the-debate--leo-vivier.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 5:47:44 -to 6:04:17    -c:a copy -c:v copy emacsconf-2020--15-moving-from-jekyll-to-orgmode-an-experience-report--adolfo-villafiorita.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 6:06:00 -to 6:27:56    -c:a copy -c:v copy emacsconf-2020--16-org-roam-presentation-demonstration-and-whats-on-the-horizon--leo-vivier.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 7:24:00 -to 7:27:09.50 -c:a copy -c:v copy emacsconf-2020--40-closing-remarks-part-1.webm
ffmpeg -y -i main.webm-2020-11-28--08-48.webm -ss 7:28:00 -to 7:50:50    -c:a copy -c:v copy emacsconf-2020--20-omg-macros--corwin-brust.webm

ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss   15:40 -to   27:27    -c:a copy -c:v copy emacsconf-2020--41-opening-remarks.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss   34:48 -to 1:03:54.75 -c:a copy -c:v copy emacsconf-2020--22-powering-up-special-blocks--musa-al-hassy.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 1:30:40 -to 1:49:18    -c:a copy -c:v copy emacsconf-2020--23-incremental-parsing-with-emacs-tree-sitter--questions--tuan-anh-nguyen.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 4:33:04 -to 4:37:30    -c:a copy -c:v copy emacsconf-2020--26-emacs-as-a-highschooler-how-it-changed-my-life--questions--pierce-wang.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 4:50:00 -to 5:59:30    -c:a copy -c:v copy emacsconf-2020--28-welcome-to-the-dungeon--erik-elmshauser-corwin-brust.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 6:08:20 -to 6:12:42.40 -c:a copy -c:v copy emacsconf-2020--30-a-tour-of-vterm--questions--gabriele-bozzola-sbozzolo.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 6:25:18 -to 6:31:04.90 -c:a copy -c:v copy emacsconf-2020--31-lakota-language-and-emacs--questions--grant-shangreaux.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 6:58:20 -to 7:20:38    -c:a copy -c:v copy emacsconf-2020--33-maxima-a-computer-algebra-system-in-emacs--fermin.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 6:58:20 -to 7:20:38    -c:a copy -c:v copy emacsconf-2020--33-maxima-a-computer-algebra-system-in-emacs--fermin.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 7:55:44 -to 8:02:02    -c:a copy -c:v copy emacsconf-2020--35-waveing-at-repetitive-repetitive-repetitive-music-zmusic--questions--zachary-kanfer.webm
ffmpeg -y -i main.webm-2020-11-29--08-44.webm -ss 8:03:32 -to 8:40:01.10 -c:a copy -c:v copy emacsconf-2020--42-closing-remarks.webm

This fiddles with the -ss to make it divisible by 4. Run this code before a copy of the ffmpeg scripts (adjusting the value of adjust as needed) and it will show only the lines that need tweaking.

  (while (re-search-forward "^ffmpeg.*?-ss +\\([^ ]++?\\) +.*$" nil t)
    (let* ((adjust 4)
           (from (save-match-data
                  (let ((s (match-string 1)) num)
                    (if (string-match "\\(\\([0-9]+\\):\\)?\\([0-9]+\\):\\([0-9]+\\)\\(.[0-9]+\\)?" s)
                          (setq num
                                (+ (* 3600 (string-to-number (or (match-string 2 s) "0")))
                                   (* 60 (string-to-number (or (match-string 3 s) "0")))
                                   (string-to-number (or (match-string 4 s) "0"))
                                   (string-to-number (concat "0" (or (match-string 5 s) "")))))
                          (if (> (% num adjust) 0)
                              (number-to-string (- num (% num adjust)))
      (if from
          (replace-match from nil nil nil 1)
        (replace-match "")))))

Thanks to SirVolta and bandali for figuring out keyframe issue!

Further reading:

(all links work with LibreJS enabled) https://blog.video.ibm.com/streaming-video-tips/keyframes-interframe-video-compression/ https://blog.streamspot.com/blog/compression-codecs-keyframes-and-the-basics-of-stream-quality https://blog.superuser.com/2012/02/24/ffmpeg-the-ultimate-video-and-audio-manipulation-tool/ https://superuser.com/questions/138331/using-ffmpeg-to-cut-up-video http://blog.webmproject.org/2010/05/inside-webm-technology-vp8-alternate.html

Collect speaker feedback

Another collaborative pad

Encode highly-compressed versions

Thanks to ArneBab for this ffmpeg script which is now documented in Extreme compression of Video with VP9 (webm) using ffmpeg. We modified it to keep the original audio.

Usage: compress-video.sh input-filename.webm output-filename.webm

nice ffmpeg -y -i $1 -c:v libvpx-vp9 -b:v 0 -crf $Q -aq-mode 2 -an -tile-columns 0 -tile-rows 0 -frame-parallel 0 -cpu-used 8 -auto-alt-ref 1 -lag-in-frames 25 -g 240 -pass 1 -f webm -threads 8 /dev/null &&
nice ffmpeg -y -i $1 -c:v libvpx-vp9 -b:v 0 -crf $Q -c:a copy -tile-columns 2 -tile-rows 2 -frame-parallel 0 -cpu-used -5 -auto-alt-ref 1 -lag-in-frames 25 -pass 2 -g 240 -threads 8 $2

Here's the original version which compresses audio too. Usage: compress-video-compressed-audio.sh input-filename.webm output-filename.webm

nice ffmpeg -y -i $1 -c:v libvpx-vp9 -b:v 0 -crf $Q -aq-mode 2 -an -tile-columns 0 -tile-rows 0 -frame-parallel 0 -cpu-used 8 -auto-alt-ref 1 -lag-in-frames 25 -g 999 -pass 1 -f webm -threads 8 /dev/null &&
nice ffmpeg -y -i $1 -c:v libvpx-vp9 -b:v 0 -crf $Q -aq-mode 2 -c:a libopus -b:a 12k -tile-columns 2 -tile-rows 2 -frame-parallel 0 -cpu-used -5 -auto-alt-ref 1 -lag-in-frames 25 -pass 2 -g 999 -threads 8 $2

Upload to alternative video hosting platforms once main announcement has been out for a few days

  • Create playlist, too
  • Try to do Peertube via Toobnix first (bandali's in charge)

Add subtitles

Take advantage of provided scripts or autogenerated files

Code sachac used to move sbv files from the Downloads directory

Autogenerated captions can save a bit of time when setting up captions. This code renames a downloaded file to match the current file's naming scheme and moves it to the right directory.

(defvar conf/subtitle-directory (expand-file-name "subtitles" default-directory) "Directory where subtitles will be kept.")
(defvar conf/download-directory "~/Downloads" "Directory where downloaded files are saved.")

(defun my/latest-file (path &optional filter)
  "Returns the newest file in PATH.
If FILTER is specified, files should match this regex."
  (car (sort (seq-remove #'file-directory-p (directory-files path 'full filter t)) #'file-newer-than-file-p)))
(defun my/rename-latest-download-as-subtitle-file ()
  "Rename the most recent downloaded file to match the current file and move it to `conf/subtitle-directory'.
To use this, open a Dired buffer with a list of the correctly-named
videos. Move your cursor to the line for the video that you have just
downloaded captions for, then call `my/rename-latest-download-as-subtitle-file.'"
  (let* ((file (my/latest-file conf/download-directory))
         (new-file (expand-file-name (concat (file-name-base (dired-get-filename)) "-autogen." (file-name-extension file)) conf/subtitle-directory)))
    (rename-file file new-file t)
    (message "%s" new-file)))
;; Ex: (local-set-key [f5] 'my/rename-latest-download)

To convert from SBV to VTT (used for the HTML5 video player) and fix timestamps so that they're not overlapping, install python3-webtt and run <subtitles/fix.py> like this: fix.py emacsconf-2020--04-music-in-plain-text--jonathan-gregory.sbv.

Add transcript sections

(defvar conf/wiki-directory "~/vendor/emacsconf-wiki" "Directory that has the public conference wiki.")

(defmacro conf/with-talk-info-file (talk &rest body)
  "Evaluate BODY in the info file for TALK.
If TALK is not specified, do it in the current buffer."
  (declare (indent 1))
  `(if ,talk
           (expand-file-name (format "%d/info/%s.md" conf/year
                                     (plist-get talk :talk-id))

(defun conf/add-transcript (&optional talk)
  "Try to add transcript for the current talk."
  (conf/with-talk-info-file talk
    (goto-char (point-min))
    (let (subtitles subed-auto-find-video all)
      (while (re-search-forward "subtitles=\"/\\(.+?\\)\"" nil t)
        (setq subtitles (cons (match-string 1) subtitles))
        (when (re-search-forward "^$\\|\\[View transcript" nil t)
          (unless (string= (match-string 0) "[View transcript")
             (if (string-match "questions" (car subtitles))
                 "[View transcript for Q&A](#transcript-questions)\n"
               "[View transcript](#transcript)\n")))))
      (when subtitles
         (lambda (subtitle-file)
           (with-current-buffer (find-file-noselect (expand-file-name subtitle-file conf/wiki-directory))
             (goto-char (point-min))
             (let (text)
               (while (subed-forward-subtitle-text)
                 (setq text (cons (subed-subtitle-text) text)))
               (setq all (mapconcat 'identity (reverse text) "\n"))))
           (if (re-search-forward (format "<!-- transcript: %s -->[ \t]*\n\\([.\r\n]*?\\)<!-- /transcript -->" (regexp-quote subtitle-file)) nil t)
                 (goto-char (match-beginning 1))
                 (delete-region (match-beginning 1) (match-end 1)))
             (goto-char (point-max))
             (insert (format "\n\n<!-- transcript: %s -->\n\n" subtitle-file))
             (insert (if (string-match "questions" subtitle-file)
                         "<a name=\"transcript-questions\"></a>\n# Transcript: Q&A\n\n"
                       "<a name=\"transcript\"></a>\n# Transcript\n\n"))
             (save-excursion (insert "\n\n<!-- /transcript -->\n")))
           (save-excursion (insert all)))
         (reverse subtitles))))))

;; (conf/add-transcript (conf/find-talk "03")), or call from a talk info page 

Other useful tidbits

Translating timezones

(setq my/timezones '("America/Toronto" "America/Los_Angeles" "UTC" "Europe/Berlin" "Asia/Kolkata" "Asia/Shanghai" "Asia/Singapore"))
(defun my/summarize-times (time timezones)
  (let (prev-day)
     (lambda (tz)
       (let ((cur-day (format-time-string "%a %b %-e" time tz))
             (cur-time (format-time-string "%H%MH %Z" time tz)))
         (if (equal prev-day cur-day)
           (setq prev-day cur-day)
           (concat cur-day " " cur-time))))
     (sort timezones (lambda (a b) (< (car (current-time-zone nil a)) (car (current-time-zone nil b)))))
     " / ")))
(defun my/org-summarize-event-in-timezones ()
      (when (derived-mode-p 'org-agenda-mode) (org-agenda-goto))
      (when (re-search-forward org-element--timestamp-regexp nil (save-excursion (org-end-of-subtree) (point)))
        (goto-char (match-beginning 0))
        (let* ((times (org-element-timestamp-parser))
               (start-time (org-timestamp-to-time (org-timestamp-split-range times)))
               (msg (format "%s - %s - %s"
                           (org-get-heading t t t t)
                           (my/summarize-times start-time my/timezones)
                           ;; (cond
                           ;;  ((time-less-p (org-timestamp-to-time (org-timestamp-split-range times t)) (current-time))
                           ;;   "(past)")
                           ;;  ((time-less-p (current-time) start-time)
                           ;;   (concat "in " (format-seconds "%D %H %M%Z" (time-subtract start-time (current-time)))))
                           ;;  (t "(ongoing)"))
                           (org-entry-get (point) "LOCATION"))))
          (message "%s" msg)
          (kill-new msg))))))

Restarting ikiwiki manually

This is needed when you change the template or if the ikiwiki process gets stuck on something.

ssh front 'sudo -iu ikiwiki ikiwiki --setup ~ikiwiki/emacsconf.setup'