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[timidity-talk] Re: extended GUS patches
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From: TAMUKI S. <ta...@li...> - 2004-07-14 15:30:45
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Hello,
On Tue, 13 Jul 2004, at 07:48:46 -1000, Greg Lee wrote:
> I don't exactly follow what you're suggesting. If a midi player
> knows only about ordinary GUS patches, how can it read extra
> information in the sample headers in order to figure out which
> samples it needs to load? It won't know about that extra
> information, because it knows only about ordinary GUS patches.
Yes, a midi player that knows only about ordinary GUS/patches, can't
read extra information in the patch header and in the sample headers.
> I've arranged things so that the first velocity layer following
> the patch header will look just like the single set of keyrange
> samples that a naive midi player expects to see and knows how
> to deal with.
You mean that "number of waveforms" in the patch header indicates the
number of the single set of keyrange samples. At this point, The
example of extended GUS/patch structure in my previous mail might
mislead. Here is the revised one:
[Patch header information (first: 5 samples, all: 11 samples)]
[Sample for low freq. range, mid vel. range, left]
[Sample for low freq. range, mid vel. range, right]
[Sample for mid freq. range, high vel. range, left]
[Sample for mid freq. range, high vel. range, right]
[Sample for high freq. range, mid vel. range, mono]
[Sample for low freq. range, low vel. range, left]
[Sample for low freq. range, low vel. range, right]
[Sample for mid freq. range, low vel. range, left]
[Sample for mid freq. range, low vel. range, right]
[Sample for low freq. range, high vel. range, left]
[Sample for low freq. range, high vel. range, right]
# The low frequency set has three velocity ranges of stereo samples;
# mid velocity range is the widest.
# The mid frequency set has two velocity ranges of stereo samples;
# high velocity range is the widest.
# The high frequency set has one velocity range of mono sample.
In this way, someone might want to create a extended GUS/patch that
has different number of velocity or channels among frequency ranges.
So, I propose the revised extended GUS/patch format:
[Extended GUS/patch format]
Byte Order: Little-endian
Patch header
Offset Bytes Contents
0 22 "GF1PATCH110\0ID#000002\0" or
"GF1PATCH100\0ID#000002\0"
22 60 Discription (in ASCII)
82 1 Number of instruments (To some patch makers, 0 means 1)
83 1 Voices (Always 14?)
84 1 Channels
85 2 Conventional waveforms
87 2 Master volume [0..127]
89 4 Data size
93 7 "SF2EXT\0" (magic) (new)
100 29 Reserved
129 2 Instrument ID [0..0xffff]
131 16 Instrument name (in ASCII)
147 4 Instrument size
151 1 Layers
152 1 Extended waveforms (new)
153 39 Reserved
192 1 Layer duplicate
193 1 Layer
194 4 Layer size
198 1 Number of samples
199 40 Reserved
:::239 bytes total
Sample header
Offset Bytes Contents
0 7 Wave name (in ASCII)
7 1 Fractions
bit 0..3: Loop offset start fractions [0/16..15/16]
bit 4..7: Loop offset end fractions [0/16..15/16]
8 4 Sample data size (s)
12 4 Loop start
16 4 Loop end
20 2 Sample rate
22 4 Low frequency
26 4 High frequency
30 4 Root frequency
34 2 Tune (Always 1, not used anymore)
36 1 Panning [0(left)..15(right)]
37 3 Envelope rates (on) (stage 0,1,2)
40 3 Envelope rates (off) (stage 3,4,5)
43 3 Envelope offsets (on) (stage 0,1,2)
46 3 Envelope offsets (off) (stage 3,4,5)
stage 0: Attack
1: Decay
2: Sustain
3,4,5: Release
49 1 Tremolo sweep
50 1 Tremolo rate
51 1 Tremolo depth
52 1 Vibrato sweep
53 1 Vibrato rate
54 1 Vibrato depth
55 1 Sampling modes
bit 0: 16-bit (versus 8-bit)
bit 1: Unsigned (versus signed)
bit 2: Looping
bit 3: Pingpong
bit 4: Reverse
bit 5: Sustain
bit 6: Envelope
bit 7: Clamped release (6th point of envelope)
56 2 Scale frequency
58 2 Scale factor [0..2048] (1024 is normal)
60 1 Low velocity (new)
61 1 High velocity (new)
62 1 Channel mode (new)
0: Mono
1: Left
2: Right
63 2 Sample volume (new)
65 1 Volume envelope delay (new)
66 1 Exclusive class (new)
67 1 Vibrato delay (new)
68 3 Mod envelope rates (on) (stage 0,1,2) (new)
71 3 Mod envelope rates (off) (stage 3,4,5) (new)
74 3 Mod envelope offsets (on) (stage 0,1,2) (new)
77 3 Mod envelope offsets (off) (stage 3,4,5) (new)
stage 0: Attack
1: Decay
2: Sustain
3,4,5: Release
80 1 Mod envelope delay (new)
81 1 Chorus effect send (new)
82 1 Reverb effect send (new)
83 2 Resonance (new)
85 2 Cutoff frequency (new)
87 1 ModEnvToPitch (new)
88 1 ModEnvToFilterFc (new)
89 1 ModLfoToFilterFc (new)
90 1 KeynumToModEnvHold (new)
91 1 KeynumToModEnvDecay (new)
92 1 KeynumToVolEnvHold (new)
93 1 KeynumToVolEnvDecay (new)
94 2 Reserved
:::96 bytes total
96 (s) Sample data
Regards,
TAMUKI Shoichi
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