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• lavu/frame : Add Dolby Vision metadata side data type

  3 janvier 2022, par Niklas Haas

  lavu/frame : Add Dolby Vision metadata side data type
  In order to be able to extend this struct later (as the Dolby Vision RPU
  
  evolves), all of the 'container' structs are considered extensible, and
  
  the individual constituent fields must instead be accessed via offsets.
  
  The precedent for this style of access is set in
  
  <libavutil/detection_bbox.h>
  Signed-off-by : Niklas Haas <git@haasn.dev>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] doc/APIchanges
  • [DH] libavutil/dovi_meta.c
  • [DH] libavutil/dovi_meta.h
  • [DH] libavutil/frame.c
  • [DH] libavutil/frame.h
  • [DH] libavutil/version.h

• lavc : Implement Dolby Vision RPU parsing

  3 janvier 2022, par Niklas Haas

  lavc : Implement Dolby Vision RPU parsing
  Based on a mixture of guesswork, partial documentation in patents, and
  
  reverse engineering of real-world samples. Confirmed working for all the
  
  samples I've thrown at it.
  Contains some annoying machinery to persist these values in between
  
  frames, which is needed in theory even though I've never actually seen a
  
  sample that relies on it in practice. May or may not work.
  Since the distinction matters greatly for parsing the color matrix
  
  values, this includes a small helper function to guess the right profile
  
  from the RPU itself in case the user has forgotten to forward the dovi
  
  configuration record to the decoder. (Which in practice, only ffmpeg.c
  
  and ffplay do..)
  Notable omissions / deviations :
  
   CRC32 verification. This is based on the MPEG2 CRC32 type, which is
  
    similar to IEEE CRC32 but apparently different in subtle enough ways
  
    that I could not get it to pass verification no matter what parameters
  
    I fed to av_crc. It's possible the code needs some changes.
  
   Linear interpolation support. Nothing documents this (beyond its
  
    existence) and no samples use it, so impossible to implement.
  
   All of the extension metadata blocks, but these contain values that
  
    seem largely congruent with ST2094, HDR10, or other existing forms of
  
    side data, so I will defer parsing/attaching them to a future commit.
  
   The patent describes a mechanism for predicting coefficients from
  
    previous RPUs, but the bit for the flag whether to use the
  
    prediction deltas or signal entirely new coefficients does not seem to
  
    be present in actual RPUs, so we ignore this subsystem entirely.
  
   In the patent's spec, the NLQ subsystem also loops over
  
    num_nlq_pivots, but even in the patent the number is hard-coded to one
  
    iteration rather than signalled. So we only store one set of coefs.
  Heavily influenced by https://github.com/quietvoid/dovi_tool
  
  Documentation drawn from US Patent 10,701,399 B2 and ETSI GS CCM 001
  Signed-off-by : Niklas Haas <git@haasn.dev>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] configure
  • [DH] libavcodec/Makefile
  • [DH] libavcodec/dovi_rpu.c
  • [DH] libavcodec/dovi_rpu.h

• fate : Limit Dolby Vision RPU test frame count

  3 janvier 2022, par Niklas Haas

  fate : Limit Dolby Vision RPU test frame count
  To avoid the ref for this growing to a very large size when attaching
  
  the parsed RPU side data. Since this sample does not have any dynamic
  
  metadata, two frames will serve just as well as 100.
  Signed-off-by : Niklas Haas <git@haasn.dev>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] tests/fate/hevc.mak
  • [DH] tests/ref/fate/hevc-dv-rpu