Cobalt Co9992-4ENC-4K-HEVC Software-Defined Broadcast Encoder - Manual (Page 49)

49

Low Latency (GDR) Mode: GDR (Gradual Decoder Refresh) is a technique that can
reduce the encoder latency. The actual GDR value (between 1 and 4 lines) makes little
difference in the latency.

PPS Insertion: This parameter controls where the Picture Parameter Set (PPS) is
inserted. It is usually not necessary to make changes to it. Setting it to Every
Field/Frame may have a negative quality impact at lower bit rates because the overhead
increases.

Deblocking Filter: Check this box to enable the deblocking filter. Disabling the
deblocking filter will degrade video quality. This control is provided for compatibility
with low-end decoders; do not disable unless absolutely necessary.

Weighted Prediction: Check this box to enable weighted prediction. Disabling weighed
prediction will degrade video quality. This control is provided for compatibility with
low-end decoders; do not disable unless absolutely necessary.
Advanced Tab–Additional MPEG-2 Video Parameters
The MPEG-2 specific Advanced Tab parameters are shown below.

GOP Structure: Select between IBBP, IBP and IP . Selecting IBBP gives the best
video quality, but some low-end decoders require IP .

Aspect Ratio: Selects the Aspect Ratio coded in the MPEG-2 bitstream. Choose it
according to your signal requirements.

VBV Value: This selects the value of the Video Buffer Verifier, which is the MPEG-2
equivalent of the CPB in AVC/HEVC. It represents a direct tradeoff between latency and
quality. It is recommended that this be left in the
Automatic setting. If Manual is
selected, an additional control becomes available:
o VBV Size (bytes): enter the desired VBV size. Reducing the VBV will reduce the
latency, but also the video quality.
Advanced Tab–VBI/Ancillary Data Insertion
The 9992-ENC can extract the following data types from the video input signal and insert them
in the compressed transport output: