DxRate

DxRate is an element that adjusts the framerate of a video stream to match a defined target framerate.
DxRate achieves this by dropping or duplicating frames based on the timestamps of incoming buffers.
DxRate always recomputes output buffer timestamps based on the target framerate, producing evenly spaced output PTS regardless of the input PTS pattern. There is no conditional passthrough — even when the input framerate already matches the target, the output PTS is regenerated from the target rate.

Key Features

Framerate Adjustment

• Ensures the output stream matches the target framerate by dropping or duplicating frames.
• The output buffer's timestamps are adjusted relative to the first input buffer's timestamp.

Throttle QoS Event

• If throttle is set to true, a Throttle QoS Event is sent upstream when frames are dropped.
• DxInfer can respond this event by applying throttling, using the throttling_delay value.
• To enable this function properly, DxRate must be placed downstream of DxInfer in the pipeline.

Framerate and Video Speed

• Framerate refers to the number of frames per second (FPS) for visual smooth playback.
• Video speed refers to playback speed (e.g., fast-forward), which is a separate concept.

Hierarchy

GObject
 +----GInitiallyUnowned
       +----GstObject
             +----GstElement
                   +----GstBaseTransform
                         +----GstDxRate

Pad Templates

Sink (input)

Property	Value
Format	video/x-raw; application/x-dxvideoraw

Src (output)

Property	Value
Format	video/x-raw; application/x-dxvideoraw

Properties

Name	Description	Type	Default Value
name	Sets the unique name of the DxRate element.	String	"dxrate0"
framerate	Sets the target framerate (FPS). This property must be configured.	Unsigned Integer	0
throttle	Determines whether to send Throttle QoS Events upstream on frame drops.	Boolean	false

Domain Mode Behavior

dxrate is a dual-mode element (see Multi-Stream Domain).

• Normal mode (sink caps = video/x-raw): a single rate state controls drop/duplicate decisions for the single stream.
• Domain mode (sink caps = application/x-dxvideoraw): per-stream rate state. Each _stream_id from DXFrameMeta has its own first-PTS reference, drop counter and duplicate counter, so framerate adjustment is applied independently per stream.

NOTE

• The framerate property is mandatory and must be explicitly set for the element to function. Setting framerate=0 results in a GST_ELEMENT_ERROR during caps negotiation.

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