[SOLVED] gdk_pixbuf_get_n_channels query

[dosh]

I am having problems with the gdk_pixbuf_get_n_channels command
I have the following code inside a program


GdkPixbuf *img;
int c;
......
img=gdk_pixbuf_new_from_file("test.png");
......
c=gdk_pixbuf_get_n_channels(img);
......


the result value of c comes out to be less than 0. I am very confused by the result as obviously I can't have a negative number of channels.

[WW]

It is probably an error code. You should check that gk_pixbuf_new_from_file succeeded before calling gdk_pixbuf_get_n_channel(img).

By the way, according to this page (http://library.gnome.org/devel/gdk-pixbuf/stable/gdk-pixbuf-file-loading.html), gdk_pixbuf_new_from_file takes two arguments.

[dosh]

Thanks WW

Yes a typo on mine it should read
img=gdk_pixbuf_new_from_file("test.png",err);
I actullay pulled the loading of the file bit of code straight from a previous working program I had. I think you are right though I will see if the "err" part of the code brings up any info that might help me.

[dosh]

worked out the error
the problem was in the err being incorrectly referenced should be as below

GdkPixbuf *img;
int c;
GError *err \* this was GError **err *\
......
img=gdk_pixbuf_new_from_file("test.png",&err); \* NOT (...,err) *\
......
c=gdk_pixbuf_get_n_channels(img);
......