| Re: Problem with MJ2 extension [message #60639 is a reply to message #60536] |
Thu, 29 May 2008 05:26   |
Haje Korth
Messages: 651
Registered: May 1997
|
Senior Member |
|
|
Mark,
I agree that in principle inter-frame compression does not necessarily have
to result quality loss by definition. However, my statement was based on
real-life my experience with the MPEG codec, which yields terrible results
all the time. MJ2 is the only built-in IDL format which gives presentable
animation results. As someone else here pointed out that without an IDL
installation you need to pay for the playback codec, which is less than
ideal. Therefore I still use VP3 (predecessor of theora) codec with the AVI
DLM, which works just as well -- at least on Windows.
Haje
"Mark" <mark.hadf@gmail.com> wrote in message
news:825110b6-dbe0-4e6c-8a00-4a64aabab84c@p39g2000prm.google groups.com...
> On May 28, 12:14 am, "Haje Korth" <haje.ko...@nospam.jhuapl.edu>
> wrote:
>> I agree that the MJ2 format is still poorly supported. But the fact that
>> no
>> inter-frame compression is used is THE advantage of the format. This way
>> each image accurately represents the underlying scientific dataset and
>> individual images are not smeared by the codec algorithm. It is accuracy
>> that matters, not file size!
>
> It depends on the purpose, obviously, and there are purposes for which
> MJ2 is appropriate (or will be when it's more widely supported)
> however those purposes generally don't match my needs.
>
> However I would like to dispute your suggestion that inter-frame
> compression necessarily degrades accuracy. In principle, animations
> with inter-frame compression can store all the information required to
> reconstruct any given frame, it's just that they spread it over
> several frames.
>
> For scenes with a limited number of colours, the old-style AVI codecs
> like Microsoft RLE (8-bit) and Microsoft Video 1 (16-bit) work very
> well. These use simple intra-frame compression plus simple inter-frame
> compression. They are either lossless (RLE) or nearly so (Video 1) and
> they achieve reasonably small file sizes and very fast playback.
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
