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Chapter 3 ’Web User Graphical Interface’ — Workflow Library
Electra VS - Version 05.10 281
User Manual - Rev. A
Chunker
Description
This workflow defines chunks for adaptive bitrate outputs. It defines the
video frames that will be encoded as IDR frames among all following
encoders.
There is no need to define chunks for audio components.
Figure 3-251. Chunker parameters
Parameters
 Chunk duration : the duration of each chunk in seconds. Chunk is
also known as fragment.
 Chunk strategy :

Fixed duration : for example, when the video frame-rate is
29.97 fps, then a 1 second chunk will contain 29 or 30 frames (the
average value will be 29.97 frames per chunk). The chunk
duration is exactly 1 second.
 Fixed number of frames : for example, when the video
frame-rate is 29.97 fps, then a 1 second chunk will always
contain 30 frames. The chunk duration is more than 1 second.
 Segment duration :
 A segment definition may be used for HLS (which usually
requires higher chunk duration than the other formats) when a
single encoding shall be used for both HLS and another format.
 When the chunker is used for a TS output with EBP signaling, it
defines the video frames that will be considered as a start of
segment.
 When an HLS output is defined, its chunk duration will be based
on the segment duration if it exists, else it will be based on the
chunk duration.
 When used, this duration must be a multiple of the chunk
duration (the start of a segment is always the start of a chunk).