Module hdr_passthrough 

HDR metadata passthrough and conversion for the transcode pipeline.

Supports HDR10 (static metadata via SMPTE ST 2086 + CTA-861.3), HLG (Hybrid Log-Gamma, ITU-R BT.2100), and a Dolby Vision profile descriptor. Metadata can be passed through unchanged, converted between compatible transfer-function families, or stripped.

Transfer function compatibility

  HDR10 (PQ/ST2084) <──> HLG (BT.2100)   ← approximate inverse-OOTF path
  HDR10 ──> SDR (BT.709)                  ← tone-map; PQ → BT.1886
  HLG   ──> SDR (BT.709)                  ← HLG OOTF collapse

Full pixel-level tone-mapping is provided by oximedia-hdr; this module handles the metadata side: mastering-display descriptors, content-light levels, and transfer-function flags embedded in the bitstream.

Structs

ContentLightLevel

Content light level metadata (CTA-861.3 MaxCLL / MaxFALL).

DolbyVisionMeta

Dolby Vision metadata payload attached to a stream.

DolbyVisionRpu

Dolby Vision RPU (Reference Processing Unit) passthrough handler.

DvRpuPassthrough

Manages a stream of Dolby Vision RPUs for passthrough mode.

Hdr10PlusDynamicMeta

HDR10+ dynamic metadata for a single scene or frame.

HdrMetadata

Unified HDR metadata attached to a video stream.

HdrProcessor

Applies an HdrPassthroughMode to a source HdrMetadata bundle, producing the metadata that should be written to the output stream.

HdrToSdrConfig

Configuration for HDR→SDR tonemapping.

MasteringDisplay

Mastering display colour volume (SMPTE ST 2086).

SdrToHdrConfig

Configuration for SDR→HDR inverse tonemapping.

Enums

ColourPrimaries

Video colour primaries (H.273 table 2).

DolbyVisionProfile

Dolby Vision profile and level.

HdrError

Errors that can occur during HDR metadata handling.

HdrPassthroughMode

How HDR metadata should be handled when transcoding.

MetadataRepairAction

Metadata repair actions that can be applied automatically.

TonemapCurve

Tonemapping curve type for HDR↔SDR conversion.

TransferFunction

Video transfer function (EOTF / OETF).

Functions

decode_cll_sei

Decodes a 4-byte CTA-861.3 payload back into ContentLightLevel.

decode_mastering_display_sei

Decodes a 24-byte SMPTE ST 2086 SEI payload back into a MasteringDisplay.

encode_cll_sei

Serialises ContentLightLevel into the 4-byte CTA-861.3 payload (MaxCLL u16 BE, MaxFALL u16 BE).

encode_mastering_display_sei

Serialises a MasteringDisplay into the 24-byte SMPTE ST 2086 SEI payload format used by HEVC and (via the same layout) AV1 metadata OBUs.

repair_hdr_metadata

Attempts to repair common HDR metadata issues in-place.