jpeg sample with ia32 ipp lib

[hongling_meng]

hello,I amtesting jpeg decoder with intel ia 32 ipp 5.1. But I found intel jpegview decoder is not complete.It can decode most jpeg file,but I have a jpeg file encodered by TI DSP board,and it can be viewed withIE andsome viewers in windows and linux.

when I decode this jpeg,I find the functionenters into DecodeScanMultiple funtion,and the result is not correct.The program do not show any error,but the picture is not correct,it looks like the pixmap is divided into 2 parts.the attachment is the jpeg file.

Can you help mewith this problem?

p.s.I can use ijg to change it to bmp file and jpegview canshowthebmp file correctly.I am puzzled.

[Vladimir_Dudnik]

Hello, thanks for reporting this. You are right, there was mistake in decoder.cpp file, you can find fix in thread at this link

http://softwareforums.intel.com/ids/board/message?board.id=IPP&message.id=4087

We also interested to know your opinion about other features of that JPEG sample. How do you find it's functionality, performance, interface and so on.

Regards,
Vladimir

[hongling_meng]

hello,thank you for your answer.I can now decode that jpeg file.But I met new problem that is strange.I test ixp ipp 5.1 lib on Intel sitsang pxa 250 Evaluation platform. At first I could not right compile jpeg apps because of the FPA and VFP error.later ,I got another crosstool that could solve this problem.I konw that intel ixp ipp 5.1 lib is compiled with MontaVista linux tool,but I do not have that tool,so I use another instead of it.

As I test ipp lib on sitsang platform,I use ijg/ijg_timing to test decode and encode time.I test the source with ipp lib and without ipp lib by setting define/undefineUSE_IPP ininclude/jconfig.h file.I found when I use ipp lib on pc,it is faster than without ipp lib.But if I test on my sitsang platform,the result is opposite.Time spent with ipp is about twice without ipp!

for example,I test ijg_timing -a

when I print the CLK variable, when decode 1024x768x4 444 jpeg file

I got 2460192 cpu_clocks with ipp lib but 1256018 cpu_clockswithout ipp lib.

what may cause this problem?It seems that this ipp lib do not work rightly/

[Vladimir_Dudnik]

It might be related to different toolchain you use to compile sample.

Vladimir