Login
Username:

Password:

Remember me



Lost Password?

Register now!

Sections

Who's Online
81 user(s) are online (48 user(s) are browsing Forums)

Members: 1
Guests: 80

emeck, more...

Support us!

Headlines

 
  Register To Post  

(1) 2 »
JPEG codec library
Just can't stay away
Just can't stay away


See User information
Please change the description on this file to something like "JPEG 2000 codec library".

Since jpeg (.jpg) and jpeg (.jp2) are two entirely different formats the current description (which is different from the one I set, which I admit was rather minimal) is very confusing IMO.

Jpeg 2000 is the successor of jpeg format and offers better compression/quality than jpeg but is from what I've read supported by none of the major browsers ATM.

Go to top
Re: JPEG codec library
Supreme Council
Supreme Council


See User information
@salass00

So it doesn't handle normal jpeg files then?

Vacca foeda. Sum, ergo edo

Mr Bobo Cornwater
Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@orgin

Thanks for fixing the description so quickly.

Quote:

So it doesn't handle normal jpeg files then?


Correct. It only has codecs for JPEG 2000 formats.

Quote:

/**
Supported codec
*/
typedef enum CODEC_FORMAT {
CODEC_UNKNOWN = -1, /**< place-holder */
CODEC_J2K = 0, /**< JPEG-2000 codestream : read/write */
CODEC_JPT = 1, /**< JPT-stream (JPEG 2000, JPIP) : read only */
CODEC_JP2 = 2 /**< JPEG-2000 file format : read/write */
} OPJ_CODEC_FORMAT;

Go to top
Re: JPEG codec library
Amigans Defender
Amigans Defender


See User information
@salass00

So, does the OS4 JPEG Datatype support JPEG2000? If not, are you planning on releasing a JPEG2000 Datatype?

Chris

Go to top
Re: JPEG codec library
Supreme Council
Supreme Council


See User information
@salass00

I see.

OT: Just e general question. Is the API on the original .so stable? Linux shared object API's doesn't always stay backwards compatible with earlier versions of the same libraries like amiga libraries does. Will your port stay backwards compatible even if the so doesn't?

Vacca foeda. Sum, ergo edo

Mr Bobo Cornwater
Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@Chris

Quote:

So, does the OS4 JPEG Datatype support JPEG2000?


No.

Quote:

If not, are you planning on releasing a JPEG2000 Datatype?


I'm looking into it, yes.

I originally created the library for my icns.datatype. Using static linking the size of the datatype was increased from about 14000 bytes to about 140000 bytes (a few k less when stripped).

Go to top
Re: JPEG codec library
Not too shy to talk
Not too shy to talk


See User information
@orgin

Quote:

OT: Just e general question. Is the API on the original .so stable? Linux shared object API's doesn't always stay backwards compatible with earlier versions of the same libraries like amiga libraries does. Will your port stay backwards compatible even if the so doesn't?

I dont see a problem here, if the API changes salass00 could simply add a new Interface to the Library.

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information

Go to top
Re: JPEG codec library
Supreme Council
Supreme Council


See User information
@ZeroG

Which does not answer the question now does it.

Vacca foeda. Sum, ergo edo

Mr Bobo Cornwater
Go to top
Re: JPEG codec library
Amigans Defender
Amigans Defender


See User information
@salass00

Cool, I'll give it a try (I'll need to find some JPEG2000s first though!)

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@orgin

If it is possible without too much work I will try to keep the API compatible by writing wrapper functions f.e. if needed. Without knowing what the possible incompatible API changes might be it is a little hard to answer more clearly though.

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@Chris

There are some .jp2 files here:
http://www.openjpeg.org/index.php?menu=samples

and a couple here:
http://www.codinghorror.com/blog/archives/000794.html

Note that I haven't added .j2k support to the datatype yet.

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@Chris

I have uploaded 0.2 which has j2k support now.

Just as a warning the Bretagne2.j2k pic (~5MB) runs out of memory here and crashes when I try to open it, others work ok except for Facade.j2k which doesn't work for some reason.

Go to top
Re: JPEG codec library
Amigans Defender
Amigans Defender


See User information
@salass00

Facade is a JPWL, whatever one of those is. It must be a slightly different form of J2K.

That compression is really good, much better than standard JPEG.

Any chance of an Installer script for your datatypes? (you're welcome to nick and modify one from one of my datatype archives)

All I need now is a utility to convert my JPEGs to JPEG2000 format

Chris

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@Chris

You can try image_to_j2k (also converts to jp2) from here:
http://os4depot.net/index.php?functio ... ary/graphics/openjpeg.lha

Quote:

Any chance of an Installer script for your datatypes? (you're welcome to nick and modify one from one of my datatype archives)


Maybe in the next version(s).

Thanks for the offer. IIRC I used one of your scripts as an example when writing the Install script for diskimage.device.

Go to top
Re: JPEG codec library
Amigans Defender
Amigans Defender


See User information
@salass00

Quote:

Just as a warning the Bretagne2.j2k pic (~5MB) runs out of memory here and crashes when I try to open it


I suspect a memory allocation function either in openjpeg.library or in the datatype, is not checking that it actually got memory.

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@Chris

The problem is in libopenjpeg. When I program I always check memory allocations and other functions that can fail so that I can handle such conditions without crashing.

The stack trace also seems to confirm this.

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@Chris

Quote:

Facade is a JPWL, whatever one of those is. It must be a slightly different form of J2K.


It didn't work because libopenjpeg wasn't compiled with -DUSE_JPWL. The file does work with v52.2 of openjpeg.library I just uploaded to OS4Depot.

Go to top
Re: JPEG codec library
Not too shy to talk
Not too shy to talk


See User information
@salass00

I have just compiled libopenjpeg 1.3, it should be faster and use less memory. I will do some tests and if all is fine, it should be in OS4Depot this weekend.

Go to top
Re: JPEG codec library
Just can't stay away
Just can't stay away


See User information
@salass00

I just have a few minor comments.

The version reported for the DT descriptors is:
"J2K . (29.7.08)" & "JP2 . (29.7.08)"
They need to be fixed so the version command interprets them correctly. (That way the version of the descriptors and the datatype will match)


The source files for the descriptors (J2K,JP2) start with the comment:
# DataType file for a RIFF-WAVE Sound

You might want to change RIFF-WAVE to JPEG2000 to avoid any confusion for developers.


Could you place the next upload in a directory before you archive it so the files don't get mixed with other files that might already exist in the destination dir?

Thanks for the good work.

P.S. Why do we need 2 descriptors (J2K, JP2)??

Go to top

  Register To Post
(1) 2 »

 




Currently Active Users Viewing This Thread: 1 ( 0 members and 1 Anonymous Users )




Powered by XOOPS 2.0 © 2001-2023 The XOOPS Project