SGI: Computer Graphics

hi everyone

hmmm was experementing a little with my O2 lately with image formats and this is what i notice.
.jpeg - loaded two halves at a time with a little delay which looks slow?
.sgi - loaded from bottom to top? or either way, with steps but a bit faster than jpeg
.pic - one time loading, very fast!

all formats uses the same picture with 1600x1024 resolution.

does it mean images using SOFTIMAGE format are fast to be rendered because it utilize the ICE? i thought JPEG should be faster coz O2 has a built-in for JPEGs? or its just for motion JPEG?

also, why did the native .sgi/.rgb format was slow compared to .pic from softimage?

sorry for this noob question

Not exactly sure but .sgi files I think are uncompressed, Jpeg uses complex compression algorithms and I am not sure about .pic but maybe it uses some simple compression like run length encoding and therefore is quick to unpack. Maybe the code that unpacks the .pic file was better written than the others... Other images have different information density and compress by different amounts. A sample set of just one image is not a good dataset to make comparisons about. Something that is all one colour will compress remarkably and uncompress formats might lose but something really complex with lots of colours might favor uncompressed format more.

R.

thanks PS! hmmm i see, and yes, .pic use rle as so as .sgi , they have this option
hmmm ok will put that on my todo list on compressed and complex algo comparison.

my purpose for this test is to find which things utilize the ICE of the O2, i use Ian's melting the ICE as reference

lets say if .pic was fast with imgview, is it safe to say if i compile a movie out of .pic images, it would be faster than a movie compose of jpegs or rgb images?

Not sure of the question but probably faster as the sum of all parts equals the speed of the whole but then it probably depends on other things like how the images are combined, I don't have the source code and I am not even sure how it is meant to work.

R.

Hi,


The O2 VICE was designed to process standard definition video in real time. If your images are bigger than this then it will take longer to decompress. From memory, the VICE supported MJPEG, h.261, and DV/DVCPRO. MJPEG is just a stream of frames, each individually compressed with JPEG.

In order to take advantage of VICE you need to use SGIs DM APIs. I seem to remember that not all the supplied SGI tools supported everything in every version but I might be mistaken. Check that the tools you are using take advantage of VICE when it's available.

You seem to have found Ian's "Melting the ICE" page which supports some of my recollections: he mentions that dmconvert doesn't always take full advantage of VICE but he doesn't mention DV/DVCPRO support.
However, it is mentioned here: http://www.futuretech.blinkenlights.nl/o2/2145.pdf


You may also want to have a look at:
+ http://www.futuretech.blinkenlights.nl/o2arch.html#ICE
+ http://www.futuretech.blinkenlights.nl/ice.html (Melting the ICE)
+ http://www.futuretech.blinkenlights.nl/o2/
+ viewtopic.php?f=16&t=15285
+ http://techpubs.sgi.com/library/tpl/cgi ... z&srch=ice
+ http://www.nekochan.net/wiki/O2#O2_Video_System

Regards,
@ndy

hehe i found this nice link for reference http://paulbourke.net/dataformats/
geeez i check the dmconvert man and i really thought i can input compiled image files and output it to a movie file hehe
but actually it can do the other way, from movie file to image files... or does it both ways? geeez i hate being dumb hehe

but hmm if mjpeg consist of jpegs, is it possible to make one with .pic images?
i want to try to play a mjpeg movie but unfortunately i couldn't find a movie in that format. tried to find converter for WinXP but its output is not supported.

Hi,



You might like to check out ffmpeg (I'm not sure what the builds for Windows are like). Be careful tho': to be useful with VICE you need to ensure that you use an SGI compatible version of MJPEG.

Have you got the AV card for your O2? If so it's probably easiest to plug a video source into that and capture it: that way it'll be in the correct format. (The VICE can encode MJPEG as well as decode it. I think there was both realtime encoding and decoding for a lot of the codecs, except DV which was never publically released; most DV comes in via IEEE1394 where it's already encoded.)


Regards,
@ndy

wow! thanks andy for this reply!
yes i check melting ICE by ian and i read this line:
"Here is a summary of those operations and actions which are accelerated by ICE (info supplied by Max Waterman of SGI):
- Selected image processing functions in imgview, imgworks, Photoshop, etc."

so hmm that's why i tried different fomrats of one picture maybe ICE will depend on file formats?
aha! i read one from the links you share:

" The default use of hardware acceleration is system dependent. On systems
with ICE hardware (O2), the default is to use hardware acceleration when
the movie is compatible with the hardware. On all other systems, the
default is not to use hardware acceleration."

ok2 will keep digging here, really thanks for the guide!

yes2 the one i tried use that ffmpeg library but i forgot where i installed it my PC is a mess hehe and yes i already tried many options? but all its MJPEG outputs is not SGI compatible

yes2 i have AV card and yes i already tried capture video from my VCR which was perfect! and indeed fast, i can feel that ICE was utilized

the reason why i dig about this is i want to make a converter in my PC side. Convert any movie file into a playable movie file in my O2 coz waaah most movies i downloaded to my O2 really slow or even will hang-up really strange i cannot play movies using mplayer.. mediaplayer only few files. even the avi's i got it will complain. i try the divx player by hmm forgot his name, also didn't work..

hehe so that's why i arrive to this noob limbo

Hi,



Ah... Now I understand more about your objectives. Try encoding on the PC side to DV. I imagine that it'll be easier than working out the esoteric MJPEG options and the quality will be higher. If the disk on your O2 can sustain 4MB/s then VICE should be able to play that file in realtime. Lots of PC video editing software knows how to export in DV.


Regards,
@ndy

No I did not write that.

R.

Hi,



Oops... Sorry. I must have had an editor error.


Regards,
@ndy

hehe my english grammar made it complicated hehe hmm ok ill try DV then, i got a software from Pinnacle maybe it have that option? will see



haha sorry it was my fault, i modify the quotes coz i cant make it work the same as before? like highlighting just specific words then quote? hehe sorry



ok time to go home guys! tonight is the start of cold winter here in my location.. till tomorrow ciao!!
btw really thanks, many is learned

Yeah, it drops down below 70 sometimes ...

waaah hamei! whats up! how is it in your side? here is weird, suddenly weather looks like summer but only with cold winter breeze hehe this CNY ill go to Henan to my girls hometown and christmas just here in shenzhen, ni na? (not sure if pinyen is right ^^)

You realize if she's taking you to meet the parents then you're going to get married ? I'm serious. You should probably not do that unless you are willing to take her for life.

On this occasion I am not being humorous ... you are playing with fire.

ey hamei! thanks hehe but lets talk about this on email, contact you there
waaah really cold down here.. i can imagine you up there!! hehehe