Format:SGX (SymbOS graphic files) - Revision history

Prodatron: /* Web links */

2024-08-10T07:40:41Z

‎Web links

2023-08-13T16:50:24Z

‎Graphic data compression

2023-05-30T14:45:18Z

2023-05-30T14:44:19Z

data compression

2023-05-30T14:35:22Z

‎Extended 4 and 16 colour graphic

2023-05-30T14:33:55Z

‎Simple 4 colour graphic: infos on compression added

2006-09-24T23:11:17Z

‎Palette

2006-09-24T20:48:22Z

2006-09-24T17:36:12Z

‎Palette

2006-09-24T17:35:15Z

‎Palette

@@ Line 136: / Line 136: @@
 ==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:Programming]]

@@ Line 121: / Line 121: @@
 <pre>
   4B  last 4 bytes of the data (not compressed)
-  1W  size of non compressed part at the beginning (usual 0)
+  1W  size of non compressed part at the beginning (always 0 for SGX files)
-  ?B  not compressed part of the data
+  ?B  not compressed part of the data (not existing in SGX files)
 ??  ?B  compressed part of the data without the last 4 bytes
          using the "ZX0 data compressor" by Einar Saukas, see

@@ Line 19: / Line 19: @@
 if compressed:
 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>
@@ Line 55: / Line 55: @@
 if compressed:
 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>

@@ Line 42: / Line 42: @@
 </pre>
-===Extended 4 and 16 colour graphic===
+===Extended 4 and 16 colour graphic part===
 <pre>
@@ Line 65: / Line 65: @@
 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 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".
 ===EOF===
@@ Line 115: / Line 114: @@
 [[Image:symbosSGX.jpg]]
 ==See also==

@@ Line 45: / Line 45: @@
 <pre>
-byte 0: 64
+byte 0: [bit0-6] 64
 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 4,5: width in pixel (1-1020 [4c] or 1-508 [16c])
 byte 6,7: height in pixel (1-65535)
 byte 8-n: linear graphic data (size = byte2,3 * byte6,7)
 </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>
 bit7-4 (high nibble): left pixel
@@ Line 63: / Line 68: @@
 * the maximum width for 16 colour graphics is 508 pixel
 * 16 colour graphics must always have an even width in bytes (2,4,...,254)
 ===Line feed===

@@ Line 8: / Line 8: @@
 ==Chunk types==
-===Simple 4 colour graphic===
+===Simple 4 colour graphic part===
 <pre>
-byte 0: width in bytes (1-63)
+byte 0: [bit0-6] width in bytes (1-63)
 byte 1: width in pixel (1-252)
 byte 2: height in pixel (1-255)
 byte 3-n: linear graphic data (size = byte0 * byte2)
 </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>
 bit7 = bit0 of pixel0 (left pixel)
@@ Line 36: / Line 41: @@
 pixel3 = bit4 + 2 * bit0 (right pixel)
 </pre>
 ===Extended 4 and 16 colour graphic===

← Older revision		Revision as of 23:11, 24 September 2006
Line 104:		Line 104:


−	~~Pallete~~ configuration an colors (for 16 colors):	+	Palette configuration and colors (for 16 colors format):

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

← Older revision		Revision as of 20:48, 24 September 2006
Line 107:		Line 107:

	[[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==

← 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]]

← Older revision		Revision as of 17:35, 24 September 2006
Line 103:		Line 103:
	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==