One of the  places JPEG2000 is heavily used is in DCP (Digital Cinema Package) 
- the format used for distribution of digital films to cinemas.

It is kind of important for me (at least notionally - I can't recall having to 
look at frames in a DCP package recently) to have support for these formats, 
and it would likely be important in many other VFX/Post production scenarios.

libjpeg-turbo does not implement JPEG2000 and its wavelet compression, or some 
additional jpeg v 7/8/9 features - its basically libjpeg6 with major 
performance improvements which does indeed cover most use cases for web / 
consumer digital photography / 8-bpp imagery.

It looks like JPEG2000 and 'normal' JPEG support are implemented as separate 
plugins in the code, and there is a cmake compile option USE_OPENJPEG which 
makes it possible to build OIIO without OpenJPEG, so it should be easy to 
remove the openpeg dependency in FreeBSD - however I thought I should highlight 
one of the areas JPEG2000 is relevant in.

-Pete



> On 23/11/2015, at 3:37 am, Shane Ambler <[email protected]> wrote:
> 
> Is switching to jpeg-turbo a possibility?
> Is there a benefit to keep using openjpeg?
> 
> I am only asking as I have been asked about disabling openjpeg in the
> oiio builds as it is one of the last to still use openjpeg. I don't
> think disabling jpeg support would be very beneficial so am exploring
> the need to use openjpeg.
> 
> Looking at the freebsd ports jpeg-turbo is used by 103 ports while
> openjpeg15 by 13 and openjpeg2 by only 4
> 
> I am not certain that jpeg-turbo supports jpeg 2000 - I don't see any
> mention in the docs. I do know that blender uses both openjpeg and
> libjpeg with a copy of openjpeg within it's source tree and the first
> commit mentions adding openjpeg for jpeg 2000 support. This would also
> indicate the two don't conflict and aren't just drop in replacements.
> 
> The goal of libjpeg-turbo is making use of SIMD instructions to get
> better performance, it claims a 2-4x speed increase, this may be a
> reason to consider using jpeg-turbo even if openjpeg is left as an
> option for only jpeg 2000 support.
> 
> I also wonder how much jpeg 2000 is used if the most popular library
> doesn't support it.
> 
> -- 
> FreeBSD - the place to B...Software Developing
> 
> Shane Ambler
> 
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> Oiio-dev mailing list
> [email protected]
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