Format:SGX (SymbOS graphic files) - Revision history

Prodatron: /* Web links */

2024-08-10T07:40:41Z

Web links

← Older revision		Revision as of 07:40, 10 August 2024
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	==Web links==		==Web links==

	* [~~http~~://www.symbos.de/~~download~~.htm~~#marke3~~ SGX file downloads]		* [https://www.symbos.org/media.htm?1 SGX file downloads]

	[[Category:SymbOS]]		[[Category:SymbOS]]
	[[Category:Programming]]		[[Category:Programming]]

Prodatron: /* Graphic data compression */

2023-08-13T16:50:24Z

Graphic data compression

← Older revision		Revision as of 16:50, 13 August 2023
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	<pre>		<pre>
	00 4B last 4 bytes of the data (not compressed)		00 4B last 4 bytes of the data (not compressed)
	04 1W size of non compressed part at the beginning (~~usual~~ 0)		04 1W size of non compressed part at the beginning (always 0 for SGX files)
	06 ?B not compressed part of the data		06 ?B not compressed part of the data (not existing in SGX files)
	?? ?B compressed part of the data without the last 4 bytes		?? ?B compressed part of the data without the last 4 bytes
	using the "ZX0 data compressor" by Einar Saukas, see		using the "ZX0 data compressor" by Einar Saukas, see

Prodatron at 14:45, 30 May 2023

2023-05-30T14:45:18Z

← Older revision		Revision as of 14:45, 30 May 2023
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	if compressed:		if compressed:
	byte 3,4: size of compressed graphic data		byte 3,4: size of compressed graphic data
	byte 5-n: compressed linear graphic data (ZX0 with ~~special~~ SymbOS header)		byte 5-n: compressed linear graphic data (ZX0 with SymbOS-specific header, see below)
	</pre>		</pre>

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	if compressed:		if compressed:
	byte 8,9: size of compressed graphic data		byte 8,9: size of compressed graphic data
	byte 10-n: compressed linear graphic data (ZX0 with ~~special~~ SymbOS header)		byte 10-n: compressed linear graphic data (ZX0 with SymbOS-specific header, see below)
	</pre>		</pre>

Prodatron: data compression

2023-05-30T14:44:19Z

data compression

← Older revision		Revision as of 14:44, 30 May 2023
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	</pre>		</pre>

	===Extended 4 and 16 colour graphic===		===Extended 4 and 16 colour graphic part===

	<pre>		<pre>
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	Please note, that currently there are some limitations:		Please note, that currently there are some limitations:
	* the maximum width for 4 colour ~~graphics~~ is 1020 pixel		* the maximum width for a 4 colour graphic part is 1020 pixel
	* the maximum width for 16 colour ~~graphics~~ is 508 pixel		* the maximum width for a 16 colour graphic part is 508 pixel
	* 16 colour ~~graphics~~ must always have an even width in bytes (2,4,...,254)		* 16 colour graphic parts must always have an even width in bytes (2,4,...,254)

	===Line feed===		===Line feed===
Line 77:		Line 77:

	This chunk has a length of 3 bytes and can be recognized with 255 in the first byte. Usually every graphic part will be linked right to the previous part. After a line feed the next graphic part will be linked below the first graphic of the previous "line".		This chunk has a length of 3 bytes and can be recognized with 255 in the first byte. Usually every graphic part will be linked right to the previous part. After a line feed the next graphic part will be linked below the first graphic of the previous "line".


	===EOF===		===EOF===
Line 115:		Line 114:

	[[Image:symbosSGX.jpg]]		[[Image:symbosSGX.jpg]]

			==Graphic data compression==

			Both simple and extended graphic parts can be stored in a compressed way.
			Compressed data has to be stored in the following SymbOS-specific way, which is used for all kind of compressed data in SymbOS:
			<pre>
			00 4B last 4 bytes of the data (not compressed)
			04 1W size of non compressed part at the beginning (usual 0)
			06 ?B not compressed part of the data
			?? ?B compressed part of the data without the last 4 bytes
			using the "ZX0 data compressor" by Einar Saukas, see
			https://github.com/einar-saukas/ZX0
			</pre>

	==See also==		==See also==

Prodatron: /* Extended 4 and 16 colour graphic */

2023-05-30T14:35:22Z

Extended 4 and 16 colour graphic

← Older revision		Revision as of 14:35, 30 May 2023
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	<pre>		<pre>
	byte 0: 64		byte 0: [bit0-6] 64
			[bit7] flag, if graphic data is compressed
	byte 1: type (0=4 colour graphic, 5=16 colour graphic)		byte 1: type (0=4 colour graphic, 5=16 colour graphic)
	byte 2,3: width in bytes (1-255 [4c] or 2-254 [16c])		byte 2,3: width in bytes (1-255 [4c] or 2-254 [16c])
	byte 4,5: width in pixel (1-1020 [4c] or 1-508 [16c])		byte 4,5: width in pixel (1-1020 [4c] or 1-508 [16c])
	byte 6,7: height in pixel (1-65535)		byte 6,7: height in pixel (1-65535)
			if uncompressed:
	byte 8-n: linear graphic data (size = byte2,3 * byte6,7)		byte 8-n: linear graphic data (size = byte2,3 * byte6,7)
			if compressed:
			byte 8,9: size of compressed graphic data
			byte 10-n: compressed linear graphic data (ZX0 with special SymbOS header)
	</pre>		</pre>

	This chunk type can be recognized with 64 in the first byte. 4 colour graphics are encoded in CPC Mode 1 format (see above). 16 colour graphics are encoded in MSX Screen 5/7 format. Every byte contains 2 pixels:		This chunk type can be recognized with 64 (uncompressed) or 192 (compressed) in the first byte. 4 colour graphics are encoded in CPC Mode 1 format (see above). 16 colour graphics are encoded in MSX Screen 5/7 format. Every byte contains 2 pixels:
	<pre>		<pre>
	bit7-4 (high nibble): left pixel		bit7-4 (high nibble): left pixel
Line 63:		Line 68:
	* the maximum width for 16 colour graphics is 508 pixel		* the maximum width for 16 colour graphics is 508 pixel
	* 16 colour graphics must always have an even width in bytes (2,4,...,254)		* 16 colour graphics must always have an even width in bytes (2,4,...,254)


	===Line feed===		===Line feed===

Prodatron: /* Simple 4 colour graphic */ infos on compression added

2023-05-30T14:33:55Z

Simple 4 colour graphic: infos on compression added

← Older revision		Revision as of 14:33, 30 May 2023
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	==Chunk types==		==Chunk types==

	===Simple 4 colour graphic===		===Simple 4 colour graphic part===

	<pre>		<pre>
	byte 0: width in bytes (1-63)		byte 0: [bit0-6] width in bytes (1-63)
			[bit7] flag, if graphic data is compressed
	byte 1: width in pixel (1-252)		byte 1: width in pixel (1-252)
	byte 2: height in pixel (1-255)		byte 2: height in pixel (1-255)
			if uncompressed:
	byte 3-n: linear graphic data (size = byte0 * byte2)		byte 3-n: linear graphic data (size = byte0 * byte2)
			if compressed:
			byte 3,4: size of compressed graphic data
			byte 5-n: compressed linear graphic data (ZX0 with special SymbOS header)
	</pre>		</pre>

	This chunk type can be recognized, if the first byte has a value between 1 and 63. The 4 colour graphic data is encoded in CPC Mode 1 format. Every byte contains 4 pixels:		This chunk type can be recognized, if the first byte has a value between 1 and 63 (uncompressed) or between 129 and 191 (compressed). The 4 colour graphic data is encoded in CPC Mode 1 format. Every byte contains 4 pixels:
	<pre>		<pre>
	bit7 = bit0 of pixel0 (left pixel)		bit7 = bit0 of pixel0 (left pixel)
Line 36:		Line 41:
	pixel3 = bit4 + 2 * bit0 (right pixel)		pixel3 = bit4 + 2 * bit0 (right pixel)
	</pre>		</pre>


	===Extended 4 and 16 colour graphic===		===Extended 4 and 16 colour graphic===

MarMSX: /* Palette */

2006-09-24T23:11:17Z

Palette

← Older revision		Revision as of 23:11, 24 September 2006
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	~~Pallete~~ configuration an colors (for 16 colors):		Palette configuration and colors (for 16 colors format):

	[[Image:symbosSGX.jpg]]		[[Image:symbosSGX.jpg]]

Prodatron at 20:48, 24 September 2006

2006-09-24T20:48:22Z

← Older revision		Revision as of 20:48, 24 September 2006
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	[[Image:symbosSGX.jpg]]		[[Image:symbosSGX.jpg]]

			==See also==

			* [[SymSee\|SymSee (picture viewer)]]
			* [[SymbOS\|SymbOS (operating system)]]
			* [[Format:VID (SymbOS video files)\|VID (SymbOS video files)]]

	==Web links==		==Web links==

MarMSX: /* Palette */

2006-09-24T17:36:12Z

Palette

← Older revision		Revision as of 17:36, 24 September 2006
Line 104:		Line 104:


	Pallete configuration an colors:		Pallete configuration an colors (for 16 colors):

	[[Image:symbosSGX.jpg]]		[[Image:symbosSGX.jpg]]

MarMSX: /* Palette */

2006-09-24T17:35:15Z

Palette

← Older revision		Revision as of 17:35, 24 September 2006
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	On the CPC old generation it means: red=2, green=2, blue=1 (= 13^0 + 23^1 + 2*3^2 = 25).		On the CPC old generation it means: red=2, green=2, blue=1 (= 13^0 + 23^1 + 2*3^2 = 25).


			Pallete configuration an colors:

			[[Image:symbosSGX.jpg]]

	==Web links==		==Web links==