HDMI 2.1 Terms with Explanations

HDMI 2.1 Terms with Explanations

HDMI 2.1 Terms

Auto Low Latency Mode (ALLM)

  1. HDMI Video Flag that automatically sets the display into the lowest latency settings.

Capabilities Data Structure (CDS)

  1. Describes Audio Capabilities of an eARC RX (Audio Playback Device) to an eARC TX (Display).

Dynamic HDR

  1. Allows for HDR metadata to dynamically change frame by frame (scene by scene).

Enhanced Audio Return Channel (eARC)

  1. Upgrade to the previous Audio Return Channel increasing bandwidth and improving discovery of devices and device capabilities. Supports 192KHz 24 Bit signals and up to 32 Channels of uncompressed audio, including object-based audio from an eARC TX (Display) to an eARC RX (Audio Playback Device).
  1. Signaling method featuring 16b/18b encoding consisting of 3-4 Fixed Rate Lanes.

Fixed Rate Lane

  1. Audio and Video transmission channel capable of carrying a fixed data rate of 3, 6, 8, 10, or 12Gbps.

Forward Error Correction (FEC)

  1. Algorithm used to correct possible transmission errors and ensure an error free transmission of the packets.

Gap Bit

  1. Data bit containing no information; Used to maintain data rate.

High Frame Rate (HFR)

  1. Traditionally used to describe films shot above 24fps. Today it is used to describe framerates above 60fps, usually 100-120fps.

Next Generation Audio (NGA)

  1. Used to describe the new audio formats for over the air broadcasting including object-based audio in ATSC 3.0. Typically referring to the Dolby AC-4 Codec.

Quick Frame Transport (QFT) or Fast VActive (FVA)

  1. Video Frames are sent faster from the source to sink (Frame Rate is not increased); Reducing overall latency.

Quick Media Switching (QMS) or VRR with M_CONST

  1. Allows Video at the same resolution to seamlessly switch between refresh rates.

Variable Refresh Rate (VRR)

  1. Dynamic refresh rate; allowing for content to be played as soon as it is rendered.