LPC2478 arm7tdmi 56mhz 8kb cache 32mb ram, jpeg decoding performance
in [ASM]
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From: Branimir Maksimovic on 8 Nov 2009 02:43 Im interested if someone has experience with this controller or processor and jpeg decoding performance. Friend of mine asked me if I can make assembler program for jpeg decoding as he said open source c programs for jpeg decoding (from jpeg site and what he can find) does not give satisfying performance. He said decoding 800x600 jpeg pictures is very slow. It would be hobby project for me (learning asm for arm7 architecture) What can I expect? Is it possible to get significant speed boost in assembly? Compiler used is gcc for c programs. Thx, Branimir.
From: Herbert Kleebauer on 8 Nov 2009 13:08 Branimir Maksimovic wrote: > Im interested if someone has experience with this controller or > processor and jpeg decoding performance. > > Friend of mine asked me if I can make assembler program for jpeg > decoding as he said open source c programs for jpeg decoding (from jpeg > site and what he can find) does not give satisfying performance. > He said decoding 800x600 jpeg pictures is very slow. Take a look at http://www.bitlib.de/pub/jpeg/pfp.zip There is a C source of a very simple jpeg decoder. The debug version (pfpdebug.c) has some loops unrolled so it is, at least on a 486, faster (this may depend on the CPU and compiler used). > It would be hobby project for me (learning asm for arm7 > architecture) Good luck. I don't think the ARM instruction set was designed for assembly programming. > What can I expect? Is it possible to get significant speed > boost in assembly? If you really try it, please report your results.
From: Branimir Maksimovic on 8 Nov 2009 17:16 Herbert Kleebauer wrote: > > Take a look at http://www.bitlib.de/pub/jpeg/pfp.zip > > >> What can I expect? Is it possible to get significant speed >> boost in assembly? > > If you really try it, please report your results. Thank you very much!
From: Branimir Maksimovic on 12 Nov 2009 18:23 Herbert Kleebauer wrote: > Branimir Maksimovic wrote: > >> Im interested if someone has experience with this controller or >> processor and jpeg decoding performance. >> >> Friend of mine asked me if I can make assembler program for jpeg >> decoding as he said open source c programs for jpeg decoding (from jpeg >> site and what he can find) does not give satisfying performance. >> He said decoding 800x600 jpeg pictures is very slow. > > Take a look at http://www.bitlib.de/pub/jpeg/pfp.zip > > There is a C source of a very simple jpeg decoder. Thank you! Because I have 64kb of high speed cpu access memory, to put there code, data and stack. SDRAM of 32 MB is on external controller which is something like usb key ;) > > If you really try it, please report your results. I will if we don;t succeed to achieve time of 5 seconds per picture. Damn external memory ;) Greets!
From: Herbert Kleebauer on 13 Nov 2009 08:48
Branimir Maksimovic wrote: > >> He said decoding 800x600 jpeg pictures is very slow. > > I will if we don;t succeed to achieve time of 5 seconds per > picture. > > Damn external memory ;) 5 seconds for one 800x600 jpeg? There must be some infinite loop in the code. |