MGW Ace Encoder
HEVC Encoding and Streaming Appliance
User Manual, Version 2.1
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by symbol. Choices are: CABAC (context-based adaptive binary arithmetic coding), or
CAVLC (Context-adaptive variable-length coding).
•
GOP Structure
- Specifies the order in which I, P, and B frames are arranged in the video
stream. GOP (Group of Pictures) choices are: IP (default), I, IBP, IBBP.
Compression settings may impact video latency. Using B-Frames will improve the quality of the compression,
achieving better quality at a given bitrate. However, usage of B-frame will increase latency. To achieve the
lowest end-to-end latency, disable B-Frames and use GOP structures with 'I' and 'P' frames only. When B-
Frames are not in use, you may decrease the buffer size of your decoder (when configurable in the video
decoder settings), to benefit from lower latency without impacting the viewing quality.
•
GOP Size
–
The intervals between I-Frames. Range is 2-300 (default is 30).
•
Closed GOP
–
The I-Frames do not contain information from previous GOPs. Select the
box to close each GOP with an I-Frame.
•
Timestamp
–
Enable to insert Timecode information within the video stream. If VITC is
available within the SDI input, it is used as the default Timecode value. If not present or
another video input is used, insert the system time.
If KLV is used, the precision timestamp from KLV metadata is also inserted in the Video
Elementary stream.
•
Latency Monitoring
–
Enable to allow end-to-end latency monitoring when decoding the
stream with MGW Ace Decoder. Latency can be monitored within MGW Ace Decoder web
interface or via HTTP command.
If enabled, Timecode input is not captured from SDI input anymore.
•
To ensure accurate Latency Monitoring, system date must be synchonized to an NTP server.
Ensure to correctly configure the NTP server in System/Date and Time section on both MGW
Ace Encoder and MGW Ace Decoder.
•
When Latency Monitoring is enabled, SDI timecode (VITC) is no more embedded.
•
VPS/SPS/PPS per Picture
- Select the box to enable Video Parameter Set (VPS),
Sequence Parameter Set (SPS), and Picture Parameter Set (PPS) within the NAL (Network
Abstraction Layer) of every picture. When the box is clear SPS and PPS will appear only in
I-Frames.
•
Insert AU Delimiters
- Select the box to enable Access Unit Delimiter in the NAL
(Network Abstraction Layer) unit of the H.264 frames.
•
Auto-Adapt to Stream Bitrates
- Select the box to allow the encoder to automatically
optimize advanced compression and streaming parameters to the bit-rate you defined for
the channel.
•
MuxRate Overhead %
- The average amount of null packets relative to the total bitrate
while streaming CBR. The default value (10) is designed for reaching the best video
quality in typical content. However, this parameter can be changed to achieve the best
quality in some other contents. Enter the allocated percentage of the stream for the
multiplexer (range is 5-1000, default is 10).
•
QP Base
- The initial quantization (compression) level value used (range is 1-51, default
is 24).
