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jpeg codec help with libjpeg6-b

Started by giobeniamino May 29, 2006
Hi,

My name is Giorgio, i'm student ( Electrical and Conputer Science
Engineer) and new on the DSP. For my final test i've to implement a
JPEG real-time decoder on BF-533 EZKIT-lite. On Google's Group i've
read that some of you used the lib of IJG (libjpeg6-b) for coding the
jpeg format.
I would like to use the same library instead of the analog SDK ( the
jpeg6-b is open source with full code access and with good
documentation), so I'm trying to optmize part of the code of the
library ( decompress only)  but i don't know where to start.
Have any one any suggest to how i can optimize the code in order to do
real-time decoding application ?

thanks for your patience and availability

giobeniamino wrote:
> Hi, > > My name is Giorgio, i'm student ( Electrical and Conputer Science > Engineer) and new on the DSP. For my final test i've to implement a > JPEG real-time decoder on BF-533 EZKIT-lite. On Google's Group i've > read that some of you used the lib of IJG (libjpeg6-b) for coding the > jpeg format. > I would like to use the same library instead of the analog SDK ( the > jpeg6-b is open source with full code access and with good > documentation), so I'm trying to optmize part of the code of the > library ( decompress only) but i don't know where to start. > Have any one any suggest to how i can optimize the code in order to do > real-time decoding application ?
I don't know anything about Analog's SDK, but if their C compiler is reasonably good, you should be able to port that library relatively easily. As for where to start, look in the documentation (or failing that, in a sample program or utility) that comes with the library that describes/shows you how to use it. You probably only need to know about a few select functions in order to use the library, and one of them is probably named something like jpeg_decode(). Locate that function, and then start porting all the other code that it needs to operate. You may want to strip out unecessary features (arithmetic coding, progressive coding, etc.) to meet your project's requirements and/or your chips memory limitations. If you have more specific questions, feel free to ask. Cheers! --M
thanks for your help,

now i'm doing some reverse to find out the functions that i need most
to realize the firmware.
thanks again and if i've trouble i'll ask....

Cheers! --- GB

mlimber ha scritto:

> giobeniamino wrote: > > Hi, > > > > My name is Giorgio, i'm student ( Electrical and Conputer Science > > Engineer) and new on the DSP. For my final test i've to implement a > > JPEG real-time decoder on BF-533 EZKIT-lite. On Google's Group i've > > read that some of you used the lib of IJG (libjpeg6-b) for coding the > > jpeg format. > > I would like to use the same library instead of the analog SDK ( the > > jpeg6-b is open source with full code access and with good > > documentation), so I'm trying to optmize part of the code of the > > library ( decompress only) but i don't know where to start. > > Have any one any suggest to how i can optimize the code in order to do > > real-time decoding application ? > > I don't know anything about Analog's SDK, but if their C compiler is > reasonably good, you should be able to port that library relatively > easily. As for where to start, look in the documentation (or failing > that, in a sample program or utility) that comes with the library that > describes/shows you how to use it. You probably only need to know about > a few select functions in order to use the library, and one of them is > probably named something like jpeg_decode(). Locate that function, and > then start porting all the other code that it needs to operate. You may > want to strip out unecessary features (arithmetic coding, progressive > coding, etc.) to meet your project's requirements and/or your chips > memory limitations. > > If you have more specific questions, feel free to ask. > > Cheers! --M