Creating a GdkPixbuf from raw Bitmap data

Question

I am trying to port a Clean graphics library (specifically, ObjectIO) to Linux with GDK. The library consists of a non-OS-specific part, which I don't want to touch because of compatibility issues, and an OS-specific part which I can touch.

One of the functions I have to implement is one that takes raw data from a .bmp file and has to build a GdkPixbuf from this. This function has to be written in C.

I am aware of the function gdk_pixbuf_new_from_file(), but I do not get the file name (and can't change that, as it's in the non-OS-specific part of the library). I only get the raw data.

I saw this manual entry, and I guess I could use gdk_pixbuf_new_from_data(), but this requires that you know the row stride of the image, of which I'm unsure how to get it.

Is there a way to get the row stride from the file? If not, the only possibility I see is to create a temporary file with the data and then call gdk_pixbuf_new_from_file() - but that would be really ugly.

I wouldn’t be surprised if the row stride was always equal to the width. — icktoofay, Aug 23 '15 at 22:35
@icktoofay at first, I thought width * 3 (you need three bytes for a 24-bit image), but that doesn't show good results yet. I also tried numbers around that. It doesn't seem to be that simple, unfortunately ... — , Aug 23 '15 at 22:50

score 1 · Answer 1 · edited Jul 06 '16 at 03:40

1

You want to use the function:

int stride = cairo_format_stride_for_width(CAIRO_FORMAT_RGB24, ImageWidth);

edited Jul 06 '16 at 03:40

Des Horsley

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answered Jul 06 '16 at 02:29

Paul

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Creating a GdkPixbuf from raw Bitmap data

1 Answers1