DxVnpuEnc

DxVnpuEnc is an element that encodes raw NV12 video frames into H.264 or H.265 bitstreams using the DEEPX VNPU hardware encoder.

Build Requirement

This element is only available when built with the --dxvnpu flag: ./build.sh --dxvnpu

Autoplugging (encodebin)

DxVnpuEnc's element rank is set dynamically at plugin initialization based on VNPU device availability:

Condition	Rank	Behavior
VNPU device present	GST_RANK_PRIMARY + 1	Preferred over SW encoders (e.g., x264enc) by encodebin
No VNPU device	GST_RANK_NONE	Excluded from autoplugging candidates

When VNPU hardware is available, encodebin will automatically select DxVnpuEnc without any explicit configuration.

Property Limitations

When autoplugged by encodebin, the codec and bitrate properties cannot be configured — the encoder will use the default values (H.264, 4096 kbps). To use custom encoding settings, instantiate dxvnpuenc explicitly in the pipeline.

Key Features

Hardware Encoding
Encodes NV12 video frames entirely on the VNPU device, offloading the CPU.

Codec Selection
Supports H.264 (AVC) and H.265 (HEVC) output codecs, configurable via the codec property.

Bitrate Control
Target encoding bitrate can be configured via the bitrate property (in kbps).

Hierarchy

GObject
 +----GInitiallyUnowned
       +----GstObject
             +----GstElement
                   +----GstVideoEncoder
                         +----GstDxVnpuEnc

Pad Templates

Sink (input)

Property	Value
Format	video/x-raw, format=(string)NV12

Src (output)

Property	Value
Format	video/x-h264, stream-format=(string)byte-stream, alignment=(string)au
	video/x-h265, stream-format=(string)byte-stream, alignment=(string)au

Properties

Name	Description	Type	Default Value	Range
codec	Video codec for encoding.	Enum (h264, h265)	h264	-
bitrate	Target encoding bitrate in kbps.	Unsigned Integer	4096	1 – 100000

Usage Example

Encode a decoded video to H.264:

gst-launch-1.0 \
  filesrc location=input.mp4 ! decodebin ! \
  video/x-raw,format=NV12 ! \
  dxvnpuenc codec=h264 bitrate=8000 ! \
  h264parse ! mp4mux ! filesink location=output.mp4

Transcode H.265 to H.264:

gst-launch-1.0 \
  filesrc location=input.h265 ! h265parse ! \
  dxvnpudec output-format=NV12 ! \
  dxvnpuenc codec=h264 bitrate=4096 ! \
  h264parse ! filesink location=output.h264

NOTE

• DxVnpuEnc accepts NV12 input only. Use DxConvert to convert other formats to NV12 before encoding.

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