NAME¶

Prima::Image::Loader - progressive loading and saving for multiframe images

DESCRIPTION¶

The toolkit provides functionality for session-based loadign and saving of multiframe images to that is is not needed to store all images in memory at once. Instead, the "Prima::Image::Loader" and "Prima::Image::Saver" classes provide the API for operating on a single frame at a time.

Prima::Image::Loader¶

        use Prima::Image::Loader;
        my $l = Prima::Image::Loader->new($ARGV[0]);
        printf "$ARGV[0]: %d frames\n", $l->frames;
        while ( !$l->eof ) {
                my ($i,$err) = $l->next;
                die $err unless $i;
                printf "$n: %d x %d\n", $i->size;
        }

new FILENAME|FILEHANDLE, %OPTIONS

Opens a filename or a file handle, tries to deduce if the toolkit can recognize the image, and creates an image loading handler. The %OPTIONS are same as recognized by "load" in Prima::Image except "map", "loadAll", and "profiles". The other options apply to each frame that will be coonsequently loaded, but these options could be overridden by supplying parameters to the "next" call.

Returns either a new loader object, or "undef" and the error string.

Note that it is possible to supply the "onHeaderReady" and "onDataReady" callbacks in the options, however, note that the first arguments in these callbacks will the newly created image.

current INDEX

Manages the index of the frame that will be loaded next. When set, requests repositioning of the frame pointer so that the next call to "next" would load the INDEXth image.

eof

Return the boolean flag is the end of the file is reached.

extras

Returns the hash of extra file data filled by the codec

frames

Returns number of frames in the file

next %OPTIONS

Loads the next image frame.

Returns either a newly loaded image, or "undef" and the error string.

reload

In case an animation file is defect, and cannot be loaded in full, the toolkit will not allow to continue the loading session and will close it automatically. If it is desired to work around this limitation, a new session must be opened. The "reload" method does this by reopening the loading session with all the parameters supplied to "new". The programmer thus has a chance to record how many successful frames were loaded, and only navigate these after the reload.

rescue BOOLEAN

If set, reopens the input stream or file on ever new frame. This may help recover broken frames.

source

Return the filename or the file handle passed to the "new" call.

Prima::Image::Saver¶

        my $fn = '1.webp';
        open F, ">", $fn or die $!;
        my ($s,$err) = Prima::Image::Saver->new(\*F, frames => scalar(@images));
        die $err unless $s;
        for my $image (@images) {
                my ($ok,$err) = $s->save($image);
                next if $ok;
                unlink $fn;
                die $err;
        }

new FILENAME|FILEHANDLE, %OPTIONS

Opens a filename or a file handle and an image saving handler. The %OPTIONS are same as recognized by "save" in Prima::Image except "images". The other options apply to each frame that will be coonsequently saved, but these options could be overridden by supplying parameters to the "save" call.

Returns either a new saver object, or "undef" and the error string.

save %OPTIONS

Saves the next image frame.

Returns a success boolean flag and an eventual error string

AUTHOR¶

Dmitry Karasik, <dmitry@karasik.eu.org>.

SEE ALSO¶

Prima::Dialog::Animate.