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Gst-nvdsmetamux#

The Gst-nvdsmetamux plugin is a NvDsBatchMeta utils plugin which forms new NvDsBatchMeta from multiple input branches. When connecting a branch to nvdsmetamux, a new pad must be requested from the muxer using gst_element_get_request_pad and the pad template sink_%u. Application needs select one active sink pad which gstbuffer will be passed to src pad. The default active sink pad is the sink pad 0. nvdsmetamux will find the nearest video frame meta based on the active sink pad video frame PTS and merge the meta data into output buffer NvDsBatchMeta. Application can set the PTS tolerance threshold, if the difference of frame PTS for the same source id is bigger than the threshold, The meta data merge will be skipped. The default of the PTS match threshold is 60 ms. Input buffer will be return if all video frame PTS are less than current selected PTS for all source id in the batch. Application can filter meta data based on source id and model unique id.

Gst-nvdsmetamux

Inputs and Outputs#

  • Inputs

    • Gst Buffer (batched)

    • NvDsBatchMeta

  • Control parameters

    • active-pad

    • pts-tolerance

    • config-file

  • Output

    • Gst Buffer (batched)

    • NvDsBatchMeta merged NvDsBatchMeta from all sink pads

Features#

The following table summarizes the features of the plugin.

Gst-nvsmetamux features#

Feature

Description

Release

Supports merging NvDsBatchMeta

Merges NvDsBatchMeta from all sink pads to one NvDsBatchMeta.

DS 8.0

Supports syncing video frame

Syncs video frame based on the frame PTS in NvDsBatchMeta.

DS 8.0

Supports selecting active sink pad

The video buffer of active sink pad will be sent to the src pad of nvdsmetamux.

DS 8.0

Supports filting meta data

Filts meta data based on source id and model id.

DS 8.0

Gst-nvdsmetamux File Configuration Specifications#

The Gst-nvdsmetamux configuration file uses a “Key File” format. The [property] group configures the general behavior of the plugin. It is the only mandatory group. The following table describe the keys supported for [property] groups.

Gst-nvdsmetamux Property Group Supported Keys#

Property

Meaning

Type and Range

Example

active-pad

Active sink pad which video buffer will be send to src pad

String

active-pad=sink_0

pts-toleranc

If the diff of frame PTS for the same source id is bigger than the threshold, The meta data merge will be skipped

Integer

pts-tolerance=60000

src-ids-model

Source IDs which need to be merge

String

src-ids-model-1=0

Gst Properties#

The following table describes the Gst properties of the Gst-nvdsmetamux plugin.

Gst-nvsmetamux gst properties#

Property

Meaning

Type and Range

Example Notes

config-file

Absolute pathname of configuration file for the Gst-nvdsmetamux element

String

config-file-path=­metamux_config.txt

Sample pipelines#

Given below are some sample pipelines to demonstrate metamux plugin’s usage, please set the appropriate configuration file and library paths.

Merging metadata from two inputs:

gst-launch-1.0 uridecodebin uri=file:///opt/nvidia/deepstream/deepstream/samples/streams/sample_1080p_h264.mp4 \
! streammux.sink_0 nvstreammux name=streammux width=1920 height=1080 batch-size=1 ! \
nvinfer config-file-path=/opt/nvidia/deepstream/deepstream/samples/configs/deepstream-app/config_infer_primary.yml \
unique-id=1 ! tee name=t t.src_0 ! queue ! nvvideoconvert disable-passthrough=1 ! queue ! \
nvtracker ll-lib-file=/opt/nvidia/deepstream/deepstream/lib/libnvds_nvmultiobjecttracker.so \
ll-config-file=/opt/nvidia/deepstream/deepstream/samples/configs/deepstream-app/config_tracker_NvDCF_max_perf.yml \
! mux.sink_0 nvdsmetamux name=mux config-file=./metamux_config.txt ! nvmultistreamtiler columns=1 rows=1 \
width=1920 height=1080 ! nvdsosd ! nveglglessink t.src_1 ! queue ! \
nvinfer config-file-path=/opt/nvidia/deepstream/deepstream/samples/configs/deepstream-app/config_infer_secondary_vehiclemake.yml \
unique-id=2 infer-on-gie-id=1 ! mux.sink_1