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Instrument sample loop points, correct pitch interpretation

This commit is contained in:
Luke Hubmayer-Werner 2023-07-26 14:41:05 +09:30
parent b5800ae0fa
commit 91181e1a78
1 changed files with 28 additions and 8 deletions
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36
scripts/loaders/sound_loader.gd
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@ -25,6 +25,14 @@ const MAX_16B = 1 << 16
func unsigned16_to_signed(unsigned):
return (unsigned + MAX_15B) % MAX_16B - MAX_15B
func get_reference_pitch_samplerate(tuning1: int, tuning2: int = 0) -> int:
# This is non-trivial and subject to change
var pitch_scale = tuning1/256.0 + tuning2/65536.0
if tuning1 < 0x80:
pitch_scale += 1.0
return int(pitch_scale * 36000)
# return (unsigned16_to_signed(pitch) + 0x8000) * 32000/4096
func process_sample(mantissa: int, exponent: int) -> int:
# For filter arithmetic the samples need to be in signed form.
# Sign-extend
@ -80,7 +88,7 @@ func make_sample(rom: File, size: int, sample_rate: int) -> AudioStreamSample:
for i in range(samples.size()-8, samples.size()):
samples[i] = clamp_short(samples[i] + (samples[i-1]*115)/64 - (samples[i-2]*13)/16)
if end:
print('End flag on packet')
# print('End flag on packet')
break
var audio_data = PoolByteArray()
for i in range(2, samples.size()):
@ -92,22 +100,34 @@ func make_sample(rom: File, size: int, sample_rate: int) -> AudioStreamSample:
func get_inst_sample_data(rom: File, id: int) -> AudioStreamSample:
rom.seek(INST_SR + (id*2))
var sample_rate := (rom.get_16() * 32000)/4096
var tuning1 := rom.get_8()
var tuning2 := rom.get_8()
var sample_rate := get_reference_pitch_samplerate(tuning1)
rom.seek(INST_LOOP + (id*2))
var loop_start_packet := rom.get_16()/9 # Note that Instrument $1F Steel Guitar has a length of $088B but a loop point of $088D which is 243.22... packets. Luckily it doesn't matter.
var lookup_offset := INST_BRR_LOOKUP + (id*3)
rom.seek(lookup_offset)
var brr_offset := read_rom_address(rom)
rom.seek(brr_offset)
var size := rom.get_16()
var sample := make_sample(rom, size, sample_rate)
#print_debug('Loaded sample instrument #%02X with lookup offset $%06X, BRR data offset $%06X and length $%04X (%f packets)' % [id, lookup_offset, brr_offset, size, size/9.0])
return sample
var num_samples := (size/9)*16
var audio := make_sample(rom, size, sample_rate)
audio.loop_mode = AudioStreamSample.LOOP_FORWARD
audio.loop_begin = loop_start_packet * 16 # Each 9byte packet is 16 samples
audio.loop_end = num_samples-1
print_debug('Loaded instrument #%02X with lookup offset $%06X, BRR data offset $%06X, length $%04X (%f packets, %d samples) and loop point %d samples' % [id, lookup_offset, brr_offset, size, size/9.0, num_samples, audio.loop_begin])
return audio
func load_sfx_samples_data(rom: File):
var sample_rates = []
rom.seek(SFX_SR)
for i in SFX_NUM:
sample_rates.append((rom.get_16() * 32000)/4096)
var tuning1 := rom.get_8()
var tuning2 := rom.get_8()
sample_rates.append(get_reference_pitch_samplerate(tuning1))
var brr_spc_addrs = []
var brr_spc_loop_addrs = []
rom.seek(SFX_BRR_SPC_TABLE)
@ -119,9 +139,9 @@ func load_sfx_samples_data(rom: File):
brr_spc_addrs[i] += SFX_BRR_START - brr_spc_start
for i in SFX_NUM:
rom.seek(brr_spc_addrs[i])
print('Loading sfx sample #%X with BRR data offset $%06X' % [i, rom.get_position()])
# print('Loading sfx sample #%X with BRR data offset $%06X' % [i, rom.get_position()])
sfx_samples.append(make_sample(rom, 900, sample_rates[i])) # Use 900 as a limit, it won't be hit, parser stops after End packet anyway
print('size of %d samples' % sfx_samples[i].data.size())
# print('size of %d samples' % sfx_samples[i].data.size())
# Called when the node enters the scene tree for the first time.