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Subject: Re: [AE] Lossless movie format
From: Brendan Bolles <brendan@fnordware.com>
In-Reply-To: <list-5472542@media-motion.tv>
Date: Tue, 13 May 2014 14:38:12 -0700
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Message-Id: <6A1755AB-00AA-49D6-BAD0-894CDD93D805@fnordware.com>
References: <list-5472542@media-motion.tv>
To: "After Effects Mail List" <AE-List@media-motion.tv>

On May 13, 2014, at 1:16 PM, Jim Curtis wrote:

> As I recall from many years ago, OMF was announced by Avid to be an =
Open (source) Media Framework that they hoped would be adopted by the =
world. =20
>=20
> That didn't happen.
>=20
> http://www.edlmax.com/FormatOmf.htm


Right.  Maybe you can fill me in on the history of OMF and we can use it =
as a cautionary tale.  There doesn't seem to be a whole lot of info =
about it.  Maybe that's part of the problem.

I'm following the example set by OpenEXR for this, and in fact will use =
a lot of OpenEXR code in this project.  A few things I think OpenEXR did =
right:


1. OpenEXR has a website.  Simple enough, but you know exactly where to =
go for the latest information.  Included on this website are links to =
sample files, right from the source.  So you know if a program can't =
read one of those files, the problem is on the program's end.


2. OpenEXR is a container plus codecs.  Containers like MXF, Matroska, =
MP4, and TIFF let you use any codec you want with them.  So you may =
think you can read that random MXF into Premiere, but then it turns out =
you often can't, which I would find very frustrating.  I don't think =
there's a program that can read every flavor of MXF, but the OpenEXR =
plug-in for After Effects can read virtually every EXR ever made.


3. OpenEXR has a high-quality open source software library that includes =
all the codecs.  The library is very easy to use: just get the file, =
point to a pixel buffer, and read.  It handles all the complexity on its =
own; you don't even have to know what a codec is.  For example, when =
OpenEXR added support for tiles, people using the scanline API just had =
to update the the latest code and the library handled all the tiling =
business for them.  They even did this with the recent addition of deep =
images.


3a. The OpenEXR library uses the BSD license.  Some licenses like the =
GPL would prevent commercial programs from using the library.  POM will =
only use code under the BSD license or similar.


4. OpenEXR is patent-free.  Most of these MXF camera files use MPEG-2 or =
H.264 as their video compression format.  But both of those are =
patent-encumbered so you can't just go make a program that uses those =
formats without going through legal hurdles.  Not a problem with OpenEXR =
or POM.


5. OpenEXR is simple.  It doesn't try to be a full-fledged media format, =
it just holds an image and metadata.  The MXF container is a complex =
media format, but POM will only use it to create self-contained movies.


Seems to me that OMF didn't have an open source library and probably =
used some sort of patent-encumbered video encoding.  All they had was a =
spec and then demanded that developers write their own software to deal =
with it.  OMF also tried to be a quasi-project file with transitions and =
such, forcing developers to handle that too.  No wonder it wasn't widely =
adopted.


Brendan=