10-bit Video Streaming

10-Bit Video Streaming

Starting in May 2016 with Encoder version 3.164.01 and Decoder version 3.161.05, Streambox Rackmount Encoders/Decoders now support 10-bit video input and output.

The process does reduce the video to 8 bit during the course of the video compression process, but the video is upconverted (dithered) to 10-bit by the Decoder, to prevent 8-bit color banding.

Required/Recommended Settings:
On Encoder: Enable 4:2:2 color, Dither OFF †(VANC ON or OFF doens't matter, but OFF may be faster)
On Decoder: VANC ON, Dither ON
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http://10.0.2.69/wiki/index.php/Encoder_changelog#Encoder_v3.164.01_.282014.2F11.2F03.29
  • New HD-Encoder setting: AJA dither 10-bit input (on/off), controls the 10 bit to 8 bit conversion on input:
    • dither=0 - (default). The incoming 10 bit samples are truncated to 8 bits
    • dither=1 - two bits of random data are added to the 10 bit sample before truncation
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http://10.0.2.69/wiki/index.php/Decoder_changelog#Decoder_v3.161.05_.282014.2F11.2F26.29
  • VANC modes fixed for AJA LHe+
  • Add dithering mode for 10-bit output (Output - DITHER), new INI flag Enable10bitDither=ON
  • Add dithering mode for VANC output (Output - DITHER), new INI value EnableVANC=2
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You will need to have encoder in 4:2:2 mode for 10-bit dithering to happen on decoder, when enabled. Besides actual color check, you can confirm in decoder log output that you see line like "DITHER IS ENABLED FOR 4:2:2 output"
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Alex writes:
HD -SDI is always 10-bit in in out inside HD-SDI protocol.
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However, unless VANC mode is selected †AJA driver is sending or receiving with 8-bit data to/from application and converts to 10-bit on output by padding 2 zero bits.
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Since working with NBC we implemented special mode on decoder to up convert 8-bit decoder output to 10-bit SDI bypassing AJA brute force algorithm.
Our 10-bit †dithering output correctly handles very dark areas improving color reproduction and significantly reducing †difference vs original.
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Only dithering on DECODER is suggested. Dithering on Encoder is not producing improvements unless content was initially handled by some 3-party 8-bit software.
Hopefully it answer your question regarding dithering on Encoder. Normally it was not recommended and can increase data rate/reduce quality if selected at lower bitrates.
We only recommend Dithering on DECODER.
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Keep in mind, that encoding/decoding path is always lossy, so some loss of information happens, however our 10-bit upconvert in VANC mode†is significantly improving on color space rendering for postproduction workflow. We were already better in color reproduction vs H264 systems due to†better codec math in pure 8-bit mode. With up convert for 10-bit we are competitive quality with 200-Mbps JPEG2000 systems at lower bitrates.
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RE VANC:†
in VANC mode, application can communicate with driver in full 10-bit mode. †All VANC data is 10-bit numbers. So video part of the signal is 10-bit too. †Thus allow us to output 10-bit video to SDI.†
Inside the codec processing is 8-bit, but 10-bit up convert on output turns it into 10 with algorithm design to handle color properly.
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There is new 8->10 bit dithering we did for NBC when VANC is enabled on newer software, so results will be much better than older systems.†That is not HDR codec though, it?s still 8-bit inside, but output is 10.
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FOR BEST 10-BIT WORKFLOW:
On Encoder: Enable 4:2:2 color, Dither OFF †(VANC ON or OFF doens't matter, but OFF may be faster)
On Decoder: VANC ON, Dither ON