Image Workflow Operation

ID: image

Description

The image operation will extract still images from a video using FFmpeg and a list of given encoding profiles. Both absolute and relative positions can be used.

Parameter Table

configuration keys	example	description
source-flavor	presenter/source	Specifies which media should be processed.
source-flavors	presenter/source, presentation/source	Specifies a list of media which should be processed. In case a flavor has been specified in source-flavor, it will be added to this list.
source-tags	engage	Specifies which media should be processed.
target-flavor	presenter/work	Specifies the flavor the new files will get.
target-tags	engage	Specifies the tags the new files will get.
encoding-profile	search-cover.http	Comma-separated list of encoding profiles to use.
time	`1` or `5%`	Comma-separated list of times in seconds or as percentage of the source track duration where the images should be extracted
target-base-name-format-second	thumbnail_%.0f%s	Used to control the target filenames for images extracted at absolute times. Mainly helpful when integrating third-party applications that prefer to use filename to distinguish individual images
target-base-name-format-percent	thumbnail_%.3f%s	Used to control the target filenames for images extracted at relative times. Mainly helpful when integrating third-party applications that prefer to use filename to distinguish individual images
end-margin	500	Safety margin at the end of the track. Sometimes, image extraction is critical at the end of the file. Using end-margin ensures, that no images are being extracted near the end of the video file to avoid problems with defective inputs. (Default: 100)

Notes:

Absolute and relative position may be mixed up in the configuration key time

Operation Example

Extract one image at position 1 second using the encoding profile search-cover.http.

  - id: image
    description: Encoding presenter preview image
    configurations:
      - source-flavor: presenter/trimmed
      - source-tags: ''
      - target-flavor: presenter/search+preview
      - target-tags: engage
      - encoding-profile: search-cover.http
      - time: 1

Extract images at three relative positions (1%, 50%, 100%) from the presenter/trimmed track. For each position, we use three different encoding profiles (example.encoding.profile.*). This operation therefore generates nine images in total. The target filenames will be formed based on the target-base-name-format-* configuration keys (prefix) and the configuration of the encoding profiles (file extension and possibly suffix).

  - id: image
    description: Extract set of thumbnails
    configurations:
      - source-flavor: presenter/trimmed
      - target-flavor: presenter/thumbnails
      - target-base-name-format-second: thumbnail_%.3f%s
      - target-base-name-format-percent: thumbnail_%.0f%s
      - encoding-profile: example.encoding.profile.small, example.encoding.profile.medium, example.encoding.profile.large
      - time: 1%, 50%, 100%
      - end-margin: 1000