Difference between revisions of "User:Buddha^/GSoC2007-ProjectDiary"

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Added info on SIERRASTANDARD's samples.
(Update to used commands in Apple IIGS AGI midi resources (Correction).)
(Added info on SIERRASTANDARD's samples.)
Line 1,461: Line 1,461:
As a sidenote program 17 seems ok but for some reason it seems not to be used
As a sidenote program 17 seems ok but for some reason it seems not to be used
at all. Maybe just not a particularly popular instrument?-)
at all. Maybe just not a particularly popular instrument?-)
== 2007-08-30 (Thursday) - SIERRASTANDARD investigation etc ==
The Apple IIGS AGI uses a file named SIERRASTANDARD that holds
the sample data used by the instruments. It's 65536 bytes in size,
it holds 8-bit unsigned sample data and all the different samples
start on 256 byte boundaries. None of the SIERRASTANDARD files I've
tested have zeroes in them (A zero would mark a premature end of a sample).
After some investigation (Looking at the file rawly imported into Audacity) etc
here's some info on it (This info applies directly to the newer SIERRASTANDARD
file used with Apple IIGS AGI v1.003+. There are some little differences in
the older SIERRASTANDARD file that's used at least with Space Quest I (AGI v1.002)):
* Number of samples (Not all unique!):
** 34
* Sample sizes log2 (2**x will give the true sample size):
** sampleSizesLog2 = [10, 10, 10, 9, 9, 10, 10, 10, 10, 10, 10, 11, 10, 10, 10, 10, 10, 10, 11, 10, 10, 11, 10, 10, 11, 10, 10, 11, 14, 13, 11, 11, 11, 11]
* Sample sizes (This table can be calculated from the sample sizes log2):
** sampleSizes = [1024, 1024, 1024, 512, 512, 1024, 1024, 1024, 1024, 1024, 1024, 2048, 1024, 1024, 1024, 1024, 1024, 1024, 2048, 1024, 1024, 2048, 1024, 1024, 2048, 1024, 1024, 2048, 16384, 8192, 2048, 2048, 2048, 2048]
*** Way to calculate this with Python: sampleSizes = map(lambda x: 2**x, sampleSizesLog2)
*** Note that sum(sampleSizes) should always be 65536 (The size of SIERRASTANDARD)
* Sample positions (This table can be calculated from the sample sizes):
** samplePos = [0, 1024, 2048, 3072, 3584, 4096, 5120, 6144, 7168, 8192, 9216, 10240, 12288, 13312, 14336, 15360, 16384, 17408, 18432, 20480, 21504, 22528, 24576, 25600, 26624, 28672, 29696, 30720, 32768, 49152, 57344, 59392, 61440, 63488]
*** Way to calculate this with Python:  samplePos = [sum(sampleSizes[:end]) for end in xrange(len(sampleSizes))]
417

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