Acorn Sprite
From Just Solve the File Format Problem
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'''Acorn Sprite''' (also known as '''RISC OS Sprite''') files are the native format for graphics on RISC OS systems. Traditionally, sprites were used to store all kinds of images. Since they support colour depths up to 32 bits per pixel it is possible to use this format to record photorealistic images (for example, from digital cameras) in this format, but improved support for compressed image formats ([[JPEG]], [[PNG]]) in RISC OS means that sprites are typically used to hold images for application icons and screen dumps. | '''Acorn Sprite''' (also known as '''RISC OS Sprite''') files are the native format for graphics on RISC OS systems. Traditionally, sprites were used to store all kinds of images. Since they support colour depths up to 32 bits per pixel it is possible to use this format to record photorealistic images (for example, from digital cameras) in this format, but improved support for compressed image formats ([[JPEG]], [[PNG]]) in RISC OS means that sprites are typically used to hold images for application icons and screen dumps. | ||
| − | == Format == | + | == Format details == |
A Sprite file consists of a 12-byte header, possibly followed by some extension data, followed by a sequence of images. Each image object begins with a 4-byte integer indicating its size. | A Sprite file consists of a 12-byte header, possibly followed by some extension data, followed by a sequence of images. Each image object begins with a 4-byte integer indicating its size. | ||
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On other platforms, at least some applications use the filename extension '''.acorn''', though it does not appear to be very common. | On other platforms, at least some applications use the filename extension '''.acorn''', though it does not appear to be very common. | ||
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| + | == Specifications == | ||
| + | * [https://www.riscosopen.org/wiki/documentation/show/Format%20Of%20Sprite Format Of Sprite] | ||
| + | * [https://www.4corn.co.uk/articles/websites/www95/acorn/library/ref/sprite.html Sprite file format] | ||
| + | * [http://www.geraldholdsworth.co.uk/Sprite/RISC_OS_Sprite_formats.pdf RISC OS Sprite Formats compiled by Gerald J Holdsworth] | ||
| + | * [http://www.wss.co.uk/pinknoise/Docs/index.html Documentation on Acorn Computers] → [http://www.wss.co.uk/pinknoise/Docs/Arc/Sprites/32bit.html 16/32 bit sprite format] | ||
| + | * [https://www.riscosopen.org/wiki/documentation/show/Screen%20Modes Screen Modes] | ||
== Software == | == Software == | ||
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* [http://www.boddie.org.uk/david/Projects/Python/Spritefile/ Spritefile] - a Python module for reading and writing Sprite files | * [http://www.boddie.org.uk/david/Projects/Python/Spritefile/ Spritefile] - a Python module for reading and writing Sprite files | ||
* [http://www.netsurf-browser.org/projects/librosprite/ LibROSprite] | * [http://www.netsurf-browser.org/projects/librosprite/ LibROSprite] | ||
| − | * [[XnView]] ( | + | * [[XnView]] (may require .acorn file extension) |
* {{Deark}} | * {{Deark}} | ||
* [https://armclub.org.uk/free/ SPRtools] | * [https://armclub.org.uk/free/ SPRtools] | ||
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* APDL DTP [https://archive.org/details/cdrom-riscos-apdl-dtp1 CD1], [https://archive.org/details/cdrom-riscos-apdl-dtp2 CD2], [https://archive.org/details/cdrom-riscos-apdl-dtp3 CD3] | * APDL DTP [https://archive.org/details/cdrom-riscos-apdl-dtp1 CD1], [https://archive.org/details/cdrom-riscos-apdl-dtp2 CD2], [https://archive.org/details/cdrom-riscos-apdl-dtp3 CD3] | ||
* [https://archive.org/details/cdrom-riscos-clipart ArtWorks ClipArt CD1] | * [https://archive.org/details/cdrom-riscos-clipart ArtWorks ClipArt CD1] | ||
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[[Category:RISC OS]] | [[Category:RISC OS]] | ||
Revision as of 15:32, 13 April 2019
Acorn Sprite (also known as RISC OS Sprite) files are the native format for graphics on RISC OS systems. Traditionally, sprites were used to store all kinds of images. Since they support colour depths up to 32 bits per pixel it is possible to use this format to record photorealistic images (for example, from digital cameras) in this format, but improved support for compressed image formats (JPEG, PNG) in RISC OS means that sprites are typically used to hold images for application icons and screen dumps.
Contents |
Format details
A Sprite file consists of a 12-byte header, possibly followed by some extension data, followed by a sequence of images. Each image object begins with a 4-byte integer indicating its size.
The 4-byte integer at offset 0 is the number of images in the file.
The 4-byte integer at offset 4 is the offset of the first image, plus 4. It is usually 16, meaning 12.
The 4-byte integer at offset 8 is the file size, plus 4.
Identifiers
On RISC OS, Sprite files have a file type of ff9 (Sprite).
On other platforms, at least some applications use the filename extension .acorn, though it does not appear to be very common.
Specifications
- Format Of Sprite
- Sprite file format
- RISC OS Sprite Formats compiled by Gerald J Holdsworth
- Documentation on Acorn Computers → 16/32 bit sprite format
- Screen Modes
Software
- Konvertor
- Spritefile - a Python module for reading and writing Sprite files
- LibROSprite
- XnView (may require .acorn file extension)
- Deark
- SPRtools
Sample files
- RISC OS Icons
- Arcade BBS: Sprite Picture files (These files may use Spark, ZIP, or other archive formats.)
- APDL DTP CD1, CD2, CD3
- ArtWorks ClipArt CD1
