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% Formats.tex
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% Blackmagic Libre
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% Copyright (C) 2023, Jeff Moe
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% This document is licensed under the Creative Commons Attribution 4.0
% International Public License (CC BY-SA 4.0) by Jeff Moe.
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\section{Formats and Codecs Used by Blackmagic}
\label{sec:overview-formats}
\index{formats}\index{codecs}

An overview of the formats used by Blackmagic.


\section{Video Samples}
Video samples of every format and codec combination from the
Cinema 6K are available here:

\url{https://spacecruft.org/spacecruft/blackmagic-libre-data}


\section{LUT}
Film to Video LUT, etc.
Dynamic range.

\begin{mdframed}[backgroundcolor=blue!10,linecolor=blue!30]
\begin{description}
  \item [Ext Video]
  \item [Video]
  \item [Film]
\end{description}
\end{mdframed}


\section{CinemaDNG}
Notes.

So CinemaDNG is the "open" HDR-like video format. Blackmagic was using it in their earlier cameras.(edited)
But they got a patent threat, so switched to their proprietary .braw, and removed support for CinemaDNG.
Patent threat may have come from "Red" (camera brand).
Or maybe Adobe.
So if you want to take a "HDR"-like photo with a DSLR, you take a picture "normal", then down a step, then up a step, for example.
But this means there can be movement between the shots, even if the camera is programmed to take the shots quickly.
With the Blackmagic internal hardware, all steps (13 of them in fact) are all taken in one shot.
Their old cameras with that feature + CinemaDNG could be a good combo.
Not sure if kdenlive etc can do CinenaDNG though.
Taking a pic with 13 steps all in one shot. wowza, that's pretty cool.
So later, you can just go in post processing and set light how you want, it is very detailed, etc.   It would pixelize dark areas that are brightened, or example.


\section{Unorganized Notes}

\begin{description}
  \item Blackmagic BRAW (somemovie.braw) format is proprietary.
  \item There is a Linux player, but you need their proprietary SDK, with registration required.
  \item The camera can do a .mov format, which linux can read.
  \item But that doesn't do the max pixel sizes (6k).
  \item I think the BRAW format is a video HDR format (e.g. takes each photo at multiple exposures).
  \item The raw still images can't be read by gimp or darktable, but rawtherapee can read them.
  \item There is one crappy ffmpeg implementation for braw, but not maintained, doesnt really work.
  \item The 4k .mov works ok.
  \item Video .mov on device at 4k looks good played with mpv. But something is a bit off with colorspace, it is like looking thru an ND filter.
  \item Like Blackmagic RAW (.braw) doesn't work by default in debian, but the ProRes (.mov) does.
  \item I can get HDMI out working. I can get 4K video recording to SD working with libre software.
  \item Not working: 6K, due to it only recording to their proprietary format.
  \item Not working: HDR (multi exposure per frame), due to it only recording to their proprietary format, afact.
  \item Definitely not libre stuff.
  \item But one of their formats is .mov, which ffmpeg, etc can read.
  \item Their other format is .braw, their proprietary raw, which can't really be read libre.
  \item One feature is interlacing of frames with different exposure levels.
  \item So "in software"/postprocessing you can set exposure values with far more control.
  \item And just better detail overall.
  \item Canon has HDR still photo built into the camera.  Or on other cameras you can just do 3 (or whatever) then use software such as darkdable to make the final image.
  \item The Blackmagic has HDR Still Image, .dng, that rawtherapee can read, but nothng else i tried can.(edited)
  \item For use with a libre toolchain, the older generation to the 6K series is better for recording video.
  \item Because it can do the CinemaDNG that in theory can by read with free software.
  \item Even their cams that at 10+ years old are still quite good, if the hunt isn't for megapixels, but image quality.
  \item The v2 series cameras all appear to use the newer proprietary Blackmagic RAW format.
  \item The DNG files, both the CinemaDNG and supposedly the braw files, are series of tiff files, or similar. This is how ffmpeg handles them, afaict.
  \item The sensor on the Blackmagic can take multiple exposures in a single shot.
  \item This makes for a better picture with more detail, better in dark areas, etc. in general.
  \item With the .braw format and the proprietary app that reads it, you can access all of these layers.
  \item So, for instance, if one part is too blown out, you can select that area and get a darker version of it, as taken by the camera, not kludge later with an algorithm. So the picture is much better.
  \item With kdenlive, iit can only read the .mov format of Blackmagic. So there is no way to access these other exposure layers.
\end{description}

