Difference between revisions of "Myst PICT resources"

From A look inside The Link @ wiki
Jump to: navigation, search
m (Protected "Myst PICT resources" [edit=autoconfirmed:move=autoconfirmed])
(DirectBits PICTs are RLE compressed)
 
(2 intermediate revisions by the same user not shown)
Line 3: Line 3:
 
PICT resources contain the main game graphics in Myst Masterpiece Edition, replacing most [[Myst_WDIB_resources|WDIBs]] of the original edition with true-color versions.
 
PICT resources contain the main game graphics in Myst Masterpiece Edition, replacing most [[Myst_WDIB_resources|WDIBs]] of the original edition with true-color versions.
  
They contain pictures stored in plain [http://en.wikipedia.org/wiki/PICT Apple PICT] format. They start with the usual 512 byte block of platform-dependent data as in regular MacOS PICT resources. JPEG contents have been observed and correctly decoded; the JPEG block starts at offset 726 and can be simply extracted and decoded.
+
The data is usually stored in plain [http://en.wikipedia.org/wiki/PICT Apple PICT] format. It starts with the usual 512 byte block of platform-dependent data as in regular MacOS PICT resources. The PICT opcodes are usually a bunch of utility ones (e.g. PnSize and DefHilite) together with a CompressedQuickTime one containing JPEG data. The JPEG block seems to always start at offset 726 into the resource and can thus be simply extracted and decoded, ignoring the complicated PICT format.
  
However, a few cases do not contain JPEG data (e.g. PICT 2258 from STONE.DAT, PICT 4109, 4112, 4113, 4447, 4461, 4462, 4479-4483, 4551, 4779, 11221, 11222 from MYST.DAT). These contain sort of invalid PICT data, as no program is able to decode them. Also note that a few perverse PICT resources just retain the WDIB format (i.e. PICT 2105 and 2112 from STONE.DAT).
+
However, a few PICT resources contain more complex PICT data, also including LongComment opcodes. Pixels are given by a DirectBitsRect opcode and they are compressed using a run-length encoding similar to [http://en.wikipedia.org/wiki/PackBits PackBits] (packType = 4 in the PixMap). You spot these cases immediately from their large size with respect to JPEG ones. Among these exceptions there are PICT 2258 from STONE.DAT, PICTs 4109, 4112, 4113, 4447, 4461, 4462, 4479-4483, 4551, 4779, 11221, 11222 from MYST.DAT.
 +
 
 +
Finally, a few perverse PICT resources just retain the WDIB format. Examples are PICTs 2105 and 2112 from STONE.DAT. Fortunately, it is quite easy to discriminate between WDIB and Apple PICT data.

Latest revision as of 22:32, 17 October 2008

Myst
Mohawk Overview
CLRC EXIT HINT INIT
MJMP MSND PICT RLST
VIEW WDIB HELP RSFL
Scripts Variables

PICT resources contain the main game graphics in Myst Masterpiece Edition, replacing most WDIBs of the original edition with true-color versions.

The data is usually stored in plain Apple PICT format. It starts with the usual 512 byte block of platform-dependent data as in regular MacOS PICT resources. The PICT opcodes are usually a bunch of utility ones (e.g. PnSize and DefHilite) together with a CompressedQuickTime one containing JPEG data. The JPEG block seems to always start at offset 726 into the resource and can thus be simply extracted and decoded, ignoring the complicated PICT format.

However, a few PICT resources contain more complex PICT data, also including LongComment opcodes. Pixels are given by a DirectBitsRect opcode and they are compressed using a run-length encoding similar to PackBits (packType = 4 in the PixMap). You spot these cases immediately from their large size with respect to JPEG ones. Among these exceptions there are PICT 2258 from STONE.DAT, PICTs 4109, 4112, 4113, 4447, 4461, 4462, 4479-4483, 4551, 4779, 11221, 11222 from MYST.DAT.

Finally, a few perverse PICT resources just retain the WDIB format. Examples are PICTs 2105 and 2112 from STONE.DAT. Fortunately, it is quite easy to discriminate between WDIB and Apple PICT data.