Post-Processing

The post-processing gives you the possibility to execute different actions after a recording has finished. You can use that to convert the files to another format, create preview images, rename / move the file etc.

Available Steps

• create a copy - Creates a copy of the original recording. All following post-processing steps are executed on the copy, not on the original recording. This means, that the post-processing can be rerun in case a step failed, because the original recording is still available.

• rename - Renames the recording with the help of variables. See Variables

• move - Moves the recording with the help of variables. See Variables

• remux / transcode - Executes FFmpeg with the given arguments on the recording. This step can be used to convert a recording to MP4 or re-encode it to a different format / resolution. The input and output file don't have to be defined. If the step was successful the input file gets deleted.

• execute script - Executes a script or program with the given arguments. You can use the variables to define what to pass over to the script.

• delete too short - Delete a recording, if it is shorter than the given duration. This post-processing step has replaced the setting, which was available in the post-processing category before

• delete original - This is a companion step for "create a copy". If you use the copy step and all other steps are successful, you probably want to get rid of the original file and just keep the result of the post-processing. That's what this step does.

• remove recording, but keep the files - Removes the recording from the recordings list, but keeps the files untouched.

• create contactsheet - create a contact sheet with preview images of the recording

• webhook - send a message via a webhook, e.g. Telegram

• concatenate - concatenate video files created within a time period

  concatenate NOTES: If you can't live with these constraints, don't use it, don't ask "Why can't I...", come up with something better - this is NOT an exhaustive list.

  • It relies on having single files to work with, not segments, for those who use the server.

  • It relies on the metadata being available, you cannot use it with a remove recording, but keep the files step.

  • The status of EVERY file has to be FINISHED - from metadata.

  • The dimensions of EVERY video have to be the same - checked by ffmpeg.

  • It uses the creation time of the video for its selection basis - from metadata.

  • The time period is counted backwards from the completion of the current recording.

  • It will work after a rename step.

  • It won't work after a remux step if you've changed container or encoded the file - limitations of concat.

  • It is recommended that recordings don't all go into a single directory but the process should cope if they do - in theory.

  • Don't use it with delete too short for obvious reasons - no metadata.

  • Wait for post-processing to finish before rushing off to shutdown CTBRec.

  • create contactsheet will use the specifications of the original file not the concatenated replacement file.

  • contactsheets for concatenated deleted files will be left behind, live with it or don't create them - CTBRec deletes files after post-processing completes.

  • I do not recommend running multiple concurrent concatenate processes - for obvious reasons.

  • It accepts the following formats for input: MKV, TS, MP4, & MOV.

  • The most reliable recording format for it to work is MKV.

  • TS is a P.I.T.A. to concatenate, video timing values will most likely be screwed, find some better parameters and tell me.

    Format	Parameters
    Default	-c copy
    TS	-c copy -fflags +genpts -avoid_negative_ts make_zero -bsf:a aac_adtstoasc
    MKV	-c copy -map 0
    MP4/MOV	-c copy -movflags +faststart

Planned for future releases

• There is no plan ... we make it up as we go.
• create timeline thumbnails - create a small thumbnail for every second or every few seconds, which can be used to very fast scan through a recording

How to configure the server to do post-processing

There is currently no user interface to configure the post-processing for the server. It has to be added manually to the server config. I suggest to start the app and configure the post-processing steps in the settings. Afterwards you close the app and copy the post-processing section from the settings.json to your server.json file. To find out, where these files are on your system, read Configuration File.

The part you have to copy is

  postProcessors: [
    ...
  ],

Variables

• $base64 - base64 encode a string/file - $base64( "Hello World" ) becomes SGVsbG8gV29ybGQ=
• $trim - removes all leading and trailing space - $trim( hello world ) becomes hello world
• $upper - converts all of the characters to upper case - $upper(hello world) becomes HELLO WORLD
• $lower - converts all of the characters to lower case - $lower(hElLo WORLD) becomes hello world
• $capitalize - capitalizes words changing the first character to upper case - $capitalize(hElLo WorLD) becomes HElLo WorLD
• $sanitize - removes problematic characters - $sanitize(hEl'Lo / WO"RLD) becomes hEl_Lo___WO_RLD. The following characters are replaced by an underscore: \, /, ', " and space
• $orElse - provide an alternative in case a variable is not set - $orElse(${variable},someValue) - becomes ${variable}, if it is set or someValue, if ${variable} is not set
• $format - formats a date, can be used with a pattern or without. Examples:
  • $format(${localDateTime}) - becomes something like 2023-02-26_12-23-15
  • $format(${localDateTime},yyyyMMdd-HHmmss) would lead to 20200928-173605

  Symbol	Meaning	Presentation	Examples
  G	era	text	AD; Anno Domini; A
  u	year	year	2004; 04
  y	year-of-era	year	2004; 04
  D	day-of-year	number	189
  M/L	month-of-year	number/text	7; 07; Jul; July; J
  d	day-of-month	number	10
  g	modified-julian-day	number	2451334
  Q/q	quarter-of-year	number/text	3; 03; Q3; 3rd quarter
  Y	week-based-year	year	1996; 96
  w	week-of-week-based-year	number	27
  W	week-of-month	number	4
  E	day-of-week	text	Tue; Tuesday; T
  e/c	localized day-of-week	number/text	2; 02; Tue; Tuesday; T
  F	day-of-week-in-month	number	3
  a	am-pm-of-day	text	PM
  h	clock-hour-of-am-pm (1-12)	number	12
  K	hour-of-am-pm (0-11)	number	0
  k	clock-hour-of-day (1-24)	number	24
  H	hour-of-day (0-23)	number	0
  m	minute-of-hour	number	30
  s	second-of-minute	number	55
  S	fraction-of-second	fraction	978
  A	milli-of-day	number	1234
  n	nano-of-second	number	987654321
  N	nano-of-day	number	1234000000
  V	time-zone ID	zone-id	America/Los_Angeles; Z; -08:30
  v	generic time-zone name	zone-name	Pacific Time; PT
  z	time-zone name	zone-name	Pacific Standard Time; PST
  O	localized zone-offset	offset-O	GMT+8; GMT+08:00; UTC-08:00
  X	zone-offset 'Z' for zero	offset-X	Z; -08; -0830; -08:30; -083015; -08:30:15
  x	zone-offset	offset-x	+0000; -08; -0830; -08:30; -083015; -08:30:15
  Z	zone-offset	offset-Z	+0000; -0800; -08:00
  p	pad next	pad modifier	1
  '	escape for text	delimiter
  ''	single quote	literal	'

  For more information see: DateTimeFormatter

  Full Example:

  $orElse(${modelGroupName},$sanitize(${modelName}))_$format(${localDateTime})_${recordingNotes}

  Webhook examples:

  Telegram:

  URL:     https://api.telegram.org/bot$TO:KEN/sendMessage
  Headers: 
  Method:  POST
  Data:    {"chat_id": <CHAT_ID>, "text": "${modelName} - finished"}
  

  Boss key: Control+Alt+Shift+b

  Signal:

  URL:     http://<IP>:<port>/v2/send
  Headers: "Content-Type: application/json"
  Method:  POST
  Data:    {"message": "${modelName} - finished", "number": "+<PHONE_NUMBER>", "recipients": [ "+<PHONE_NUMBER>" ]}