Image rendering

Danny769 · Post by **Danny769** » Wed Apr 26, 2006 1:14 pm

I need to load several images in sequence to imatate a movie.
All it does is crash

I currently load a picture in place for background, and then bliz it and flip it.

It does about 9 and then crashes.
Any ideas?

I need closer to 200 images to load, and yes i relize that is asking alot of lua, but how would i go about doing it, in a maner that will work

RanDom_ErrOr · Post by **RanDom_ErrOr** » Wed Apr 26, 2006 4:12 pm

wouldnt it be easier to make a .gif or a .avi and then render that as a texture onto a sprite that is the same size as the screen (or whatever size you need)

that way you can do things like dynamic resizing, layering, alpha transperiencies... etc... etc... etc...

Danny769 · Post by **Danny769** » Wed Apr 26, 2006 8:57 pm

Do you have an example as for the code for avi?

And will it look like a vid?

Giuliano · Post by **Giuliano** » Thu Apr 27, 2006 4:02 am

Why do you need to load 200 images and how big are they ? I can't think of a reason why you would need this, the best way is to load each as necessary (ie: if in a game env't then load necessary imgs for each level)

imhotep · Post by **imhotep** » Thu Apr 27, 2006 5:48 am

1. code please
2. use timers and load a new image when timer:time()>timelimit
3. don't load all images before the loop, the psp doesn't have that much resources
4. unassign the old picture when the new one is blitted
5. oldpic=""

Danny769 · Post by **Danny769** » Thu Apr 27, 2006 11:18 am

How do i unasign a pic.

All i have been doing is loding a new on to replace it

KawaGeo · Post by **KawaGeo** » Fri Apr 28, 2006 1:35 am

No need to unassign anything in Lua. Use the same variable name for a new value of *any* type. Lua has a built-in garbage collector to take care of cleaning up inside.

Altair · Post by **Altair** » Sat May 20, 2006 2:40 am

Yeah i was wondering how that works. It doesn't clean it up when you use another variable, right? Because if i do that and i don't empty the old var. myself, it crashes if i do that a couple of times.

KawaGeo · Post by **KawaGeo** » Sat May 20, 2006 3:34 am

All global non-nil variables can be left untouched in the namespace. It has been advised to declare all variables as locals if possible since they can be garbage-collected sooner or later automatically.

All parameters in every Lua function are locals.

romero126 · Post by **romero126** » Sat May 20, 2006 5:24 am

The crash sounds like a memory error, try freeing up images as you display them and dont load them all up at once. That could possibly be your biggest issue.

Altair · Post by **Altair** » Sat May 20, 2006 7:24 am

romero126 wrote:The crash sounds like a memory error, try freeing up images as you display them and dont load them all up at once. That could possibly be your biggest issue.

Yeah thats what i figured. I clear the images, but it crashes always (if it crashes) at the moment it loads four 1000x1000 images after eachother. However it doesn't crash alot anymore, since i clear the unused images. I guess i dont clear everything. I'll look for more stuff i can kick out of the memory.

romero126 · Post by **romero126** » Sun May 21, 2006 11:12 am

1000x1000px?

The limits on the PSP is only 480x272px size

Altair · Post by **Altair** » Sun May 21, 2006 11:57 am

romero126 wrote:1000x1000px?

The limits on the PSP is only 480x272px size

nope thats the resolution of the screen. I use 1000x1000 images but ofcourse can only blit part of it to the screen.

KawaGeo · Post by **KawaGeo** » Sun May 21, 2006 12:50 pm

A single 1000x1000 image loaded would eat up about 4MB of VRAM, would it?

The VRAM is only 32MB in PSP, I believe.

PS Is it VRAM or just RAM?

Altair · Post by **Altair** » Sun May 21, 2006 8:32 pm

i dont know if its vram or ram, but the image itself is only 58 kB. Well thats the biggest. The others are smaller. I also have a 11 kB one.

KawaGeo · Post by **KawaGeo** » Mon May 22, 2006 4:21 am

Aren't they all compressed before loading?

When loaded unto the memory, each image is uncompressed, that's, pixel by pixel, correct?

Teggles · Post by **Teggles** » Mon May 22, 2006 5:36 am

LuaPlayer cannot support loading images larger than 512x512. Fact.

For your "animation", you'd do something like this:

image = Image.load("")
screen:clear()
screen:blit(0, 0, image)
screen.flip()
image = Image.load("")
screen.waitVblankStart(25)

...then back to the screen:clear and go from there. The vBlank function is how long it will stay on screen. Note this is only an example.

romero126 · Post by **romero126** » Mon May 22, 2006 9:14 am

Im so glad teggles came to this website. Its about time.

youresam · Post by **youresam** » Mon May 22, 2006 11:21 am

I have heard that LuaPlayer can load 1000x1000 jpgs, but I havent tried it out.

I was helping someone out with code today, and the same thing happened. For some reason, a 480x272 image takes up exactly 1mb RAM. Now, with Lowser, Lua has only 16mb to use.

As for how to remove images, you should.
theimage = nil
collectgarbage()

that will remove the image from memory then garbage collect to rid of it forever.

KawaGeo · Post by **KawaGeo** » Mon May 22, 2006 1:50 pm

youresam wrote:... a 480x272 image takes up exactly 1mb RAM.

Are you referring to the double buffer which occupies exactly 1 MB in the memory space, 4 bytes for the front and 4 for the back buffer?

That explains why the funny number of 272 for the height.

Altair · Post by **Altair** » Tue May 23, 2006 6:22 am

Ok im getting a little tired of this. How about you guys try something out yourself first. Im using a 1000x1000 JPG image of 58 kB and it works. It wont work with PNG but it does with JPG. And yoursam I was the one who told you this remember?