View Full Version : Save to image file

04-10-2003, 01:36 AM
I'd like to be able to draw to the p-buffer then save the scene to a file, e.g. in jpeg format. I have a demo program that draws to the p-buffer, but I don't know the easiest way to write the pixel data to a file. Any suggestions? (I can work in either W32 or Linux).

My ultimate goal is to create a video (e.g. mpeg or avi). I can do this externally from a collection of jpegs, using various programs. It would be cool to be able to encode to an mpeg file within my own program. Is this feasible?


04-10-2003, 01:48 AM

why yes, yes it is. I do it, too. You need to a) work out some way of encoding a bitmap into jpeg (i recommend libjpeg), and b) to copy the framebuffer.

There isn't much more I can say about it; its just code monkey work. Get libjpeg and work out how to encode a jpeg from a char*, then grab a char* from the screen. easy


04-10-2003, 02:25 AM
John, I believe you were responding to my first question, about writing to a jpeg file. What about the second part (creating a video)?


04-10-2003, 02:47 AM

04-10-2003, 10:35 PM
I'm currently using the libjpeg to save screenshots, and then I use mencoder(see mplayer) under Linux to encode them into a divx video.

This works well, except that saving let's say 25 jpeg/second slow down quite much my engine. I'll try to save raw data. Mencoder can read them I think, that would save quite a lot of processing. If that does not work, I'll try another image format that requires less processing power, like pcx (which still have some compression, to save on disk access).