int ok = hw_RegisterFileType(hwPluginBase *self, int type, STRPTR name,
                STRPTR mime, STRPTR ext, ULONG formatid, ULONG flags);

You have to pass a pointer to your plugin's hwPluginBase in parameter 1. Hollywood passes this pointer to you when it first calls your InitPlugin() function. You also have to specify the root type of the file format you want to register. The following types are currently supported:

HWFILETYPE_IMAGE:

Register specified file type as an image file format.

HWFILETYPE_ANIM:

Register specified file type as an animation file format.

HWFILETYPE_SOUND:

Register specified file type as a sound file format.

HWFILETYPE_VIDEO:

Register specified file type as a video file format.

HWFILETYPE_ICON:

Register specified file type as an icon file format. (V9.0)

HWFILETYPE_FONT:

Register specified file type as a font file format. (V10.0)

The name you have to specify in parameter 3 must be a human-readable name of the file type you want to register, e.g. "IFF ILBM". The name you specify here may use spaces. The fourth parameter is optional and allows you to specify the MIME type for the file format you want to register. If you don't want to provide this, pass NULL as the fourth parameter. Parameter number 5 must contain the extension(s) used by this file type. The extension(s) must be specified without the dot. If the file type supports more than one extension, separate the individual extensions using a vertical bar character (|), e.g. "iff|ilbm|lbm". The formatid parameter is only used if HWFILETYPEFLAGS_SAVE is set in the flags parameter. In that case, you have to pass the identifier of this file format here. This must match the identifier that is returned by your implementations of functions like RegisterImageSaver() or RegisterAnimSaver().

Finally, RegisterFileType() accepts the following flags:

HWFILETYPEFLAGS_SAVE:

If this flag is set, you're registering a saver file type. You must register loaders and savers in two separate calls. It is not possible to register loader and saver within a single call to hw_RegisterFileType().

HWFILETYPEFLAGS_ALPHA:

This flag indicates that your plugin can load or save alpha channel information, depending on whether HWFILETYPEFLAGS_SAVE is set. This is only applicable for HWFILETYPE_IMAGE and HWFILETYPE_ANIM.

HWFILETYPEFLAGS_QUALITY:

This flag indicates that your plugin supports lossy compression of image data. It is only supported by for HWFILETYPE_IMAGE and HWFILETYPE_ANIM and the HWFILETYPEFLAGS_SAVE flag must be set. The quality level is passed to your plugin saver as a value ranging between 0 (bad quality) to 100 (excellent quality).

HWFILETYPEFLAGS_FPS:

This flag indicates that your plugin can save animations with different frames per second settings. It is only supported by HWFILETYPE_ANIM together with the HWFILETYPEFLAGS_SAVE flag set.

RegisterFileType() is usually called in your InitPlugin() function but make sure that you have at least Hollywood 5.3 before attempting to call this function!

self

pointer to a hwPluginBase as passed to your InitPlugin() function

type

file type to register (see above)

name

human-readable name of this file type

mime

MIME type for this file format or NULL

ext

extension(s) for this file type; multiple extensions must be separated by a vertical bar (|)

formatid

when registering output file types, the unique identifier used by this format (see above)

flags

additional flags (see above)

ok

True for success, False on failure

hw_RegisterFileType(self, HWFILETYPE_IMAGE, "JPEG 2000", NULL,
                      "jp2|j2k", 0, HWFILETYPEFLAGS_ALPHA);

hw_RegisterFileType(self, HWFILETYPE_IMAGE, "JPEG 2000 (JP2)", NULL,
                      "jp2", outfmt[0], HWFILETYPEFLAGS_SAVE|
                      HWFILETYPEFLAGS_ALPHA|HWFILETYPEFLAGS_QUALITY);

hw_RegisterFileType(self, HWFILETYPE_IMAGE, "JPEG 2000 (J2K)", NULL,
                      "j2k", outfmt[1], HWFILETYPEFLAGS_SAVE|
                      HWFILETYPEFLAGS_ALPHA|HWFILETYPEFLAGS_QUALITY);