AmigaFFH-package: The Amiga File Format Handler package
In AmigaFFH: Commodore Amiga File Format Handler

AmigaFFH-package

R Documentation

The Amiga File Format Handler package

Description

The Amiga File Format Handler package (AmigaFFH) is designed to interpret file formats that were native to Commodore Amiga machines.

Details

In combination with the adfExplorer package this package can be used to interpret older file formats that were native to the Commodore Amiga. The focus of this package will be on the older system (Amiga OS <= 3.0). This will allow you to analyse and interpret these files in the scripted environment of R.

Note that all functions and methods in this package are implemented as scripted source code and may not run very fast.

Supported File Formats

This package supports a number of file formats. The ProTracker module file format requires sophisticated interpretation and a dedicated package (ProTrackR) is developed for that purpose.

The following formats are supported by this package (to some extend):

Amiga Basic binary encode scripts and Amiga Basic shapes which were used by such scripts to display specific graphics.
Bitmap Font (*.font). Originally fonts were stored in separate files on the Amiga. An overarching *.font file contained generic information, amongst others the specific pixel heights that were available for a font. The actual font bitmap images were stored in separate files. There was a file available for each individual font height. For more details see AmigaBitmapFont and AmigaBitmapFontSet.
Interchange File Format (IFF). This file format is actually a container for a wide variety of data flavours. Of which the following are supported:
- 8SVX (8-bit sampled voices (i.e., audio)). There are no major restrictions in this package's implementation.
- ANIM (animations). Not all display modes are supported as per ILBM. Furthermore, the vertical byterun encoding for the animation frames is the only encoding currently supported.
- ILBM (InterLeaved BitMap images). Specific display modes (such as ‘extra halfbrite’) can in some cases be decoded, but encoding for these modes may not (yet) be supported.
For more details see IFFChunk, interpretIFFChunk, read.iff and write.iff.
Hardware sprites. This format follows the hardware structure for displaying sprites on the screen. It is usually not used as a file format as such, but it can be found embedded in some files (for instance the mouse pointer is embeded as a hardware sprite in the ‘system-configuration’ file). For more details see hardwareSprite.
System-configuration. A file that was stored in the ‘devs’ directory of a system disk. As the file name suggests, it holds many of the systems configurations. See SysConfig for more details.
Workbench icons (*.info). Icons (i.e., graphical representation of files and directories on the Amiga) were stored as separate files with the extension *.info. See AmigaIcon for more details.

In future versions of this package more file types may be added to this list.

In Addition...

Several helper functions are also exported by this package. This will give you access to older compression techniques, such as the run length encoding (packBitmap) and delta Fibonacci compression (deltaFibonacciCompress). But also other techniques that will help in converting modern files into classic file formats and vice versa. Such as for instance the function to dither full colour images to a limited colour palette.