Cobalt Co9992-4ENC-4K-HEVC Software-Defined Broadcast Encoder - Manual (Page 44)

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
GOP Mode: Select between Open GOP and Closed GOP. The normal setting is Open
GOP, whereby the last frame(s) of a GOP can depend on frames in the next GOP. Closed
GOP is used for some storage applications, and is required by some CDNs (such as
YouTube); there is a very small negative impact in video quality if Closed GOP is
selected.

GOP Length (frames) : Select the GOP (Group Of Pictures) length, in frames. The
actual GOP length may be slightly different depending on the GOP structure. For
broadcast applications, a GOP corresponding to 0.5 sec is recommended. Larger GOP
values can improve video quality.

Adaptive GOP : Check this box to enable Adaptive GOP. When Adaptive GOP is
enabled, a GOP may be terminated earlier on a scene change. Scene change detection
can increase video quality for some content.

Scene and Pixel Picture Sensitivity : These controls are only active if Adaptive GOP is
checked. They control the scene change sensitivity at the pixel and frame levels.
Moving the control to the left reduces the sensitivity, and moving them to the right
increases it. For some content, having the sensitivity too high may cause video quality
issues.

Enable Video Signal Type: If this box is checked, video type information metadata is
inserted in the video elementary stream. Additional controls become available to
configure this metadata, as indicated below:
If necessary, these parameters should be set to match the characteristics of the incoming
video input signal. For example, for a PQ10 HDR signal with WCG, the following
settings are suggested:
Note that the Video Full Range checkbox is not available in MPEG-2 mode.