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

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Added info on done work on 2007-08-14 - 2007-08-17.
(Added info on done work on 2007-08-13.)
(Added info on done work on 2007-08-14 - 2007-08-17.)
Line 1,125: Line 1,125:
is next monday, on the 20th. That hadn't really sunk in yet in my mind so this means
is next monday, on the 20th. That hadn't really sunk in yet in my mind so this means
this week's going to include lots of ScummVM hacking :).
this week's going to include lots of ScummVM hacking :).
== 2007-08-14 (Tuesday) - General Apple IIGS sound hacking #1 ==
Worked on the Apple IIGS sound code.
== 2007-08-15 (Wednesday) - General Apple IIGS sound hacking #2 ==
More work on the Apple IIGS sound code.
== 2007-08-16 (Thursday) - Inspecting Apple IIGS MIDI sound resources ==
Played around with the Apple IIGS AGI midi sound resources. Yep, they're
standard MIDI files with a 16-bit little endian 0x0002 header. Sometimes they
start with 0xFC (Stop sequence) right after the header with no encoded delta-time
before the command. And sometimes they end by simply exhausting the midi stream's
length and not giving a 0xFC (Although it might be just that I'm not parsing the
files 100% correctly yet and that's what's making it happen). Also some of the
midi streams seem to have additional data after the first encountered 0xFC. I
looked at the additional trailing data from some of the files and at a first
glance it seems they're full of commands for centering the pitch wheel on different
channels, setting some default values for different controllers or something like that.
Here are some statistics about the Apple IIGS AGI midi sound resources I tested:
* Used commands in the Apple IIGS AGI midi resources (Approximate counts):
** 0x80: 00064488 "Note off" (Varying parameters)
** 0x90: 00065516 "Note on" (Varying parameters)
** 0xB0: 00006252 "Controller" (Varying parameters)
** 0xC0: 00001574 "Program Change" (Varying parameters)
** 0xE0: 00000146 "Pitch Wheel" (Only used with parameter 0x2000 i.e. wheel center)
** 0xFC: 00000271 "Stop sequence" (No parameters for this, ends the stream)
== 2007-08-17 (Friday) - First Apple IIGS sample playing! ==
Got an experimental and not-pretty sound mixing code to run and heard the first
Apple IIGS sample playing at a near reasonable pitch too :-). Whee! Getting something
concrete done raises the spirit! Had some red wine and blue cheese for
celebration :-).
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