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Metadata Preprocessing

If the source stream already contains KLV, KlvInjector lets you decide how that metadata should be handled before the final packet is injected.

Existing KLV Handling Modes​

  • Drop Existing KLV: remove the source KLV PID from the output.
  • Keep Existing KLV: pass the source KLV through unchanged.
  • Restamp Existing KLV: rewrite the source packet timestamp using current time or a predefined initial time.
  • Merge Existing KLV: merge the source packet with the default packet.

Template Packets​

You can add or replace selected metadata fields by providing a template packet. The template can be either:

  • a binary KLV packet
  • a JSON file that mirrors the MISB 0601 hierarchy

When Add/Replace is enabled, KlvInjector injects the template values into every resulting packet. If the same field already exists in the incoming metadata, it is replaced.

Preprocessing setup

Figure: Metadata preprocessing parameters.

The template packet timestamp is ignored, so Tag 2 may be omitted or left with any value.

Template packet

Figure: Example template packet.

Decoded template packet

Figure: Decoded template packet.

You can use the KlvComposer tool to build template packets.

KlvComposer

Figure: Creating template packets with KlvComposer.

Default Packet Insertion​

You can define a minimum interval between metadata packets. If no metadata arrives within that interval, KlvInjector generates and injects a default packet with a valid timestamp.

Default packet setup

Figure: Minimum interval for default-packet insertion.

note

If Min Interval is used together with Add/Replace or remove operations, the generated default packet is preprocessed in the same way as regular incoming packets.