APOLLO & ECW/JP2 Discussions

[Christiaan]

I'm attempting to evaluate the capabilities and speed of the ECW JP2 SDK for one of our projects. Unfortunately, while using the decompressor example 4 (the one demonstrating NCSSetIOCallbacks) I've run into a problem opening anything other than sample data .jp2 files. Specifically, I'm using p0_07.j2k file used in the OpenJPEG conformance tests. The callbacks eventually fail in a seek call that attempts to access an address way past the end of the file. It appears that .j2k files work correctly using the C++ interface but due to our intended use, I'm limited to using the C functions. Any help would be greatly appreciated.

Christiaan

[JoeBob]

So...what version of the ECWSDK are you using?  Windows or Linux?  Do you have any small code snippets that can be sharred to see if it can be reproduced??

[Christiaan]

I'm using version 5.3.0 of the SDK on Windows 10. The code I used was sample 4 in the decompressor examples of the SDK, built using vc14 as x64 executable. Also, here's a link to the image I was trying to read:

https://github.com/uclouvain/openjpeg-data/blob/master/input/conformance/p0_07.j2k

Thanks.

[haiyan_qu]

Do you mean you get this error? 

best

haiyan

[Christiaan]

Yes, that would be the one. It appears that the problem is caused by the Library calling the provided FileSeekCB function with a file offset of 0xff4fff51 (which happens to be the first 4 "magic" bytes of any j2k file). This in turn forces the FileSeekCB function to return NCS_FILEIO_ERROR (48).

[haiyan_qu]

I see, the fseek return -1, and FileSeekCB returns NCS_FILEIO_ERROR.

According to SDK development team, this seems to be a known issue. Anyway I will report CR defect for this issue.

static NCSError FileSeekCB(void *pClientData, UINT64 nOffset, UINT32 nOrigin)
{
	MyDataStruct *pData = (MyDataStruct*)pClientData;

	if(pData && pData->pFile) {
		int nRet;
		
		nRet = fseek(pData->pFile, (long)nOffset, nOrigin);
			
		if(nRet == 0) {
			return(NCS_SUCCESS);
		}
		return(NCS_FILEIO_ERROR);
	}
	return(NCS_INVALID_PARAMETER);
}

Thanks & best regards!

haiyan

[haiyan_qu]

Here is the CR defect

CR 1-QR3Z2P Unable to load .j2k files using provided decompress example 4 (SDK 5.3.0 Windows) 

[Christiaan]

Thanks for submitting the defect. Do you know if there is an ETA on the fix? Also, is there somewhere I can track the status of this CR and be notified of it's resolution?

[haiyan_qu]

You can create SR (service request), and then you should be able to get notification for the status.

Are you use the free Read-only SDK or Read-write SDK?

best

haiyan

[Christiaan]

Read only, for the time being.