I am trying to understand what is Advanced HDR by Technicolor that will be implemented on 2017 LG TV.
"Advanced HDR by Technicolor combines award-winning technologies: Technicolor HDR ITM
and Technicolor HDR
This unique system, based on Technicolor’s open HDR approach, delivers networks in real-time with a mix of HDR and SDR in a single stream. No matter the content’s HDR curve, it ensures the best viewing quality for every end-user on every device type Technicolor.
HDR ITM up-converts legacy content to HDR, while Technicolor HDR, the distribution solution, ensures that it’s distributed and accurately displayed simultaneously on both HDR and SDR screens providing a consistent viewing experience."
I think Technicolor HDR is described in the ETSI TS 103 433 specification (i.e. SL-HDR1).
There is no standardized display adaptation in a legacy HDR10 ecosystem.
Technicolor HDR introduces a standardized display adaptation in a HDR10 ecosystem using the SMPTE ST 2094-20 (Philips) / 2094-30 (Technicolor) dynamic metadata.
"The system typically uses HEVC Main 10 profile for the bitstream generation and decoding. It includes a pre-processing block, prior to encoding, that converts an input HDR signal into an SDR version. Metadata can be generated in this step. After encoding and decoding the SDR signal, such metadata can be used in a post-processing step to reconstruct an HDR version of the signal. The decoded SDR video can be directly rendered on an SDR display without adaptation."
Decoder in a set-top box
Decoder in a TV
"The pre-encoding conversion process converts an input linear RGB 4:4:4 signal to SDR 10-bit Y’CbCr 4:2:0 signal by applying the following successive steps:
a) a conversion from an input linear RGB 4:4:4 representation to a non-linear representation using the inverse PQ EOTF,
b) a colour format conversion from non-linear PQ R’G’B’ 4:4:4 signal to Y’CbCr 4:4:4,
c) a conversion step that converts a floating-point to a fixed-point representation (i.e. 10 bits), narrow range,
d) a chroma down-conversion component that converts data from 4:4:4 to 4:2:0, resulting in a PQ 10-bit 4:2:0 Y’CbCr signal (PQ10),
e) a dynamic range adaptation (DRA) step that applies three different transfer functions to the 4:2:0 Y’, Cb, and Cr components of the PQ10 signal to generate a 10-bit SDR 4:2:0 Y’CbCr signal.
The resulting Y’CbCr signal, having BT.709/BT.2020 transfer characteristics and BT.2020 color primaries, is then encoded, using an HEVC Main 10 compliant encoder. The DRA transfer functions can be implemented in the shape of 1D-LUTs that directly apply to the PQ10 Y, Cb and Cr components, in 4:2:0 format.
After HEVC Main 10 compliant decoding, the decoded signal has BT.709/BT.2020 transfer characteristics and BT.2020 colour primaries. The post-decoding inverse conversion processing is the inverse of the pre-encoding processing. It is made of the following steps:
a) an inverse DRA process, converting the SDR 10-bits Y’CbCr 4:2:0 signal into a PQ10 compatible signal using the inverse DRA transfer functions,
b) a chroma up-conversion that converts data from Y’CbCr 4:2:0 to Y’CbCr 4:4:4,
c) a conversion step that converts a fixed-point representation, i.e. 10 bits, to a floating-point representation,
d) a colour representation conversion from Y’CbCr 4:4:4 to R’G’B’ 4:4:4,
e) a conversion using the PQ EOTF from the input R’G’B’ 4:4:4 to linear RGB 4:4:4."
Decoder in a set-top box
Input HDR video >> Pre-processing >> SDR + dynamic metadata >> HEVC encoder >> SDR bitstream + dynamic metadata in HEVC SEI >> HEVC decoder > Post-processing > CTA HDR10 uncompressed video >> HDMI 2.0a >> HDR10 compliant TV
Input HDR video >> Pre-processing >> SDR + dynamic metadata >> HEVC encoder >> SDR bitstream + dynamic metadata in HEVC SEI >> HEVC decoder > Post-processing > HLG uncompressed video >> HDMI 2.0b >> HLG compliant TV
Input HDR video >> Pre-processing >> SDR + dynamic metadata >> HEVC encoder >> SDR bitstream + dynamic metadata in HEVC SEI >> HEVC decoder >> HDMI >> SDR compliant TV