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665 lines
25 KiB
Python
665 lines
25 KiB
Python
#!/usr/bin/env python3
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"""s3m2taud.py — Convert Scream Tracker 3 (.s3m) to TSVM Taud (.taud)
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Usage:
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python3 s3m2taud.py input.s3m output.taud [-v]
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Limits:
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- Up to 15 S3M channels (excess disabled; hard error if pattern count
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× channel count > 256).
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- Sample bin is 770048 bytes; if all samples together exceed this, every
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sample is globally resampled down (with c2spd adjusted) so pitch is
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preserved.
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- AdLib instruments are skipped.
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- Effects mapped: D (vol-slide), E/F (pitch slide, rough approx),
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SC (note-cut), A (initial speed), T (initial BPM). Others dropped.
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Pitch-slide approximation:
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Amiga-period mode: taud_arg ≈ s3m_arg * 2 (mid-register heuristic)
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Linear-slide mode: taud_arg = s3m_arg * 4 (exact)
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"""
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import argparse
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import gzip
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import math
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import struct
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import sys
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VERBOSE = False
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def vprint(*a, **kw):
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if VERBOSE:
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print(*a, **kw, file=sys.stderr)
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# ── S3M constants ────────────────────────────────────────────────────────────
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S3M_MAGIC = b"SCRM"
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S3M_TYPE_PCM = 1
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S3M_NOTE_EMPTY = 0xFF
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S3M_NOTE_OFF = 0xFE
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S3M_ORDER_SKIP = 0xFE
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S3M_ORDER_END = 0xFF
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# S3M effect letters (1-based: 1='A', 2='B', …)
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EFF_A = 1 # set speed
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EFF_B = 2 # jump to order
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EFF_C = 3 # pattern break
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EFF_D = 4 # volume slide
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EFF_E = 5 # porta down
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EFF_F = 6 # porta up
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EFF_G = 7 # tone porta
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EFF_H = 8 # vibrato
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EFF_I = 9 # tremor
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EFF_J = 10 # arpeggio
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EFF_K = 11 # vibrato+volslide
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EFF_L = 12 # porta+volslide
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EFF_M = 13 # channel vol
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EFF_N = 14 # chan vol slide
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EFF_O = 15 # sample offset
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EFF_P = 16 # pan slide
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EFF_Q = 17 # retrigger
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EFF_R = 18 # tremolo
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EFF_S = 19 # special (sub-cmds)
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EFF_T = 20 # set BPM
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EFF_U = 21 # fine vibrato
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EFF_V = 22 # global vol
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EFF_W = 23 # global vol slide
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EFF_X = 24 # set pan
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EFF_Y = 25 # panbrello
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EFF_Z = 26 # sync
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# ── Taud constants ───────────────────────────────────────────────────────────
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TAUD_MAGIC = bytes([0x1F,0x54,0x53,0x56,0x4D,0x61,0x75,0x64])
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TAUD_VERSION = 1
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TAUD_HEADER_SIZE = 32 # magic(8)+ver(1)+numSongs(1)+compSize(4)+rsvd(2)+sig(16)
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TAUD_SONG_ENTRY = 16 # offset(4)+voices(1)+pats_lo(1)+pats_hi(1)+bpm(1)+tick(1)+pad(7)
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SAMPLEBIN_SIZE = 770048
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INSTBIN_SIZE = 16384 # 256 instruments × 64 bytes
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SAMPLEINST_SIZE = SAMPLEBIN_SIZE + INSTBIN_SIZE # 786432
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PATTERN_ROWS = 64
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PATTERN_BYTES = PATTERN_ROWS * 8 # 512
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NUM_PATTERNS_MAX = 4095
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NUM_CUES = 1024
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CUE_SIZE = 32 # packed 12-bit×20 voices + instruction + pad
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NUM_VOICES = 20
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SIGNATURE = b"s3m2taud/TSVM " # 16 bytes
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# Taud note constants
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NOTE_NOP = 0xFFFF
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NOTE_KEYOFF = 0x0000
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NOTE_CUT = 0xFFFE
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TAUD_C3 = 0x4000
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# ── S3M parser ───────────────────────────────────────────────────────────────
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class S3MHeader:
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__slots__ = ('title','order_count','inst_count','pat_count',
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'flags','cwt_v','sample_type','global_vol',
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'initial_speed','initial_tempo','master_vol',
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'linear_slides','default_pan_flag',
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'channel_settings','pan_values','order_list',
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'inst_ptrs','pat_ptrs')
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def parse_s3m(data: bytes) -> S3MHeader:
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if len(data) < 0x60:
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sys.exit("error: file too short to be S3M")
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if data[0x2C:0x30] != S3M_MAGIC:
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sys.exit("error: not an S3M file (bad magic at 0x2C)")
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h = S3MHeader()
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h.title = data[0x00:0x1C].rstrip(b'\x00').decode('latin-1', errors='replace')
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h.order_count = struct.unpack_from('<H', data, 0x20)[0]
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h.inst_count = struct.unpack_from('<H', data, 0x22)[0]
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h.pat_count = struct.unpack_from('<H', data, 0x24)[0]
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h.flags = struct.unpack_from('<H', data, 0x26)[0]
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h.cwt_v = struct.unpack_from('<H', data, 0x28)[0]
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h.sample_type = data[0x2B] # 1=signed, 2=unsigned
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h.global_vol = data[0x30]
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h.initial_speed = data[0x31] # ticks per row
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h.initial_tempo = data[0x32] # BPM
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h.master_vol = data[0x33]
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h.linear_slides = bool(h.flags & 0x40) # flag bit 6 → linear freq slides
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h.default_pan_flag = data[0x35] # 0xFC → use pan values
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# Channel settings: bytes 0x40..0x5F; bit 7 = disabled
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h.channel_settings = list(data[0x40:0x60])
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# Order list
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off = 0x60
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h.order_list = list(data[off:off + h.order_count])
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# Instrument parapointers (×16 = file offset)
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off2 = off + h.order_count
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h.inst_ptrs = [struct.unpack_from('<H', data, off2 + i*2)[0] * 16
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for i in range(h.inst_count)]
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# Pattern parapointers
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off3 = off2 + h.inst_count * 2
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h.pat_ptrs = [struct.unpack_from('<H', data, off3 + i*2)[0] * 16
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for i in range(h.pat_count)]
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# Default pan values (if present)
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pan_off = off3 + h.pat_count * 2
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h.pan_values = []
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if h.default_pan_flag == 0xFC and pan_off + h.inst_count <= len(data):
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for i in range(h.inst_count):
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h.pan_values.append(data[pan_off + i])
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# per-channel pan is in channel settings nibbles (separate from above)
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return h
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class S3MInstrument:
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__slots__ = ('itype','filename','memseg','length','loop_begin','loop_end',
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'volume','flags','c2spd','name','sample_data','signed')
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def parse_instruments(data: bytes, h: S3MHeader) -> list:
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insts = []
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for ptr in h.inst_ptrs:
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if ptr + 0x50 > len(data):
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vprint(f" warning: instrument pointer {ptr:#x} out of range, skipping")
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insts.append(None)
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continue
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inst = S3MInstrument()
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inst.itype = data[ptr]
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inst.filename = data[ptr+1:ptr+13].rstrip(b'\x00').decode('latin-1', errors='replace')
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# memseg: 3 bytes at offsets 0x0D,0x0E,0x0F — high byte first (quirk)
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memseg_hi = data[ptr + 0x0D]
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memseg_lo = struct.unpack_from('<H', data, ptr + 0x0E)[0]
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inst.memseg = (memseg_hi << 16) | memseg_lo
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inst.length = struct.unpack_from('<I', data, ptr + 0x10)[0]
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inst.loop_begin = struct.unpack_from('<I', data, ptr + 0x14)[0]
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inst.loop_end = struct.unpack_from('<I', data, ptr + 0x18)[0]
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inst.volume = data[ptr + 0x1C]
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inst.flags = data[ptr + 0x1F] # bit0=loop, bit1=stereo, bit2=16bit
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inst.c2spd = struct.unpack_from('<I', data, ptr + 0x20)[0] or 8363
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inst.name = data[ptr + 0x30:ptr + 0x4C].rstrip(b'\x00').decode('latin-1', errors='replace')
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inst.signed = (h.sample_type == 1)
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inst.sample_data = b''
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if inst.itype == S3M_TYPE_PCM:
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sample_off = inst.memseg * 16
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sample_len = inst.length
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is_16bit = bool(inst.flags & 4)
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is_stereo = bool(inst.flags & 2)
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if sample_off + sample_len > len(data):
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vprint(f" warning: sample '{inst.name}' data out of range, zeroing")
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inst.sample_data = bytes(min(sample_len, 256))
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else:
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raw = data[sample_off:sample_off + sample_len]
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inst.sample_data = _normalise_sample(raw, inst.signed, is_16bit, is_stereo, inst.name)
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inst.length = len(inst.sample_data)
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inst.loop_begin = min(inst.loop_begin, inst.length)
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inst.loop_end = min(inst.loop_end, inst.length)
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insts.append(inst)
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return insts
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def _normalise_sample(raw: bytes, signed: bool, is_16bit: bool, is_stereo: bool, name: str) -> bytes:
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"""Return unsigned 8-bit mono sample bytes."""
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out = []
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stride = (2 if is_16bit else 1) * (2 if is_stereo else 1)
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i = 0
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while i + stride <= len(raw):
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if is_16bit:
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if is_stereo:
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l16 = struct.unpack_from('<h', raw, i)[0]
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r16 = struct.unpack_from('<h', raw, i+2)[0]
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s = (l16 + r16) >> 1
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else:
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s = struct.unpack_from('<h', raw, i)[0]
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v = (s >> 8) + 128
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else:
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if is_stereo:
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l8 = raw[i]; r8 = raw[i+1]
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raw_s = (l8 + r8) // 2
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else:
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raw_s = raw[i]
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if signed:
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v = ((raw_s ^ 0x80) & 0xFF) # signed→unsigned
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else:
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v = raw_s
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out.append(v & 0xFF)
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i += stride
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if is_16bit or is_stereo:
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vprint(f" info: '{name}' converted to unsigned 8-bit mono ({len(out)} samples)")
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return bytes(out)
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# ── S3M pattern parser ───────────────────────────────────────────────────────
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class S3MRow:
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"""One cell in a pattern grid."""
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__slots__ = ('note','inst','vol','effect','effect_arg')
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def __init__(self):
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self.note = S3M_NOTE_EMPTY # 0xFF=empty, 0xFE=off, else (oct<<4|pitch)
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self.inst = 0
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self.vol = -1 # -1 = not set (use instrument default)
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self.effect = 0 # 1-based letter index (0=none)
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self.effect_arg = 0
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def parse_patterns(data: bytes, h: S3MHeader) -> list:
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"""Returns list[pat_idx] of list[channel][row] → S3MRow."""
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patterns = []
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for pi, ptr in enumerate(h.pat_ptrs):
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# 32 channels × 64 rows
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grid = [[S3MRow() for _ in range(PATTERN_ROWS)] for _ in range(32)]
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if ptr == 0 or ptr + 2 > len(data):
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patterns.append(grid)
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continue
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pat_len = struct.unpack_from('<H', data, ptr)[0]
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end = min(ptr + 2 + pat_len, len(data))
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pos = ptr + 2
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row = 0
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while row < PATTERN_ROWS and pos < end:
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b = data[pos]; pos += 1
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if b == 0:
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row += 1
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continue
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ch = b & 0x1F
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has_n = bool(b & 0x20)
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has_v = bool(b & 0x40)
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has_e = bool(b & 0x80)
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cell = grid[ch][row] if ch < 32 else S3MRow()
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if has_n:
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if pos + 1 >= end: break
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cell.note = data[pos]; pos += 1
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cell.inst = data[pos]; pos += 1
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if has_v:
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if pos >= end: break
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cell.vol = data[pos]; pos += 1
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if has_e:
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if pos + 1 >= end: break
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cell.effect = data[pos]; pos += 1
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cell.effect_arg = data[pos]; pos += 1
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patterns.append(grid)
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return patterns
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# ── Note / effect encoding ───────────────────────────────────────────────────
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def encode_note(s3m_note: int) -> int:
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if s3m_note == S3M_NOTE_EMPTY:
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return NOTE_NOP
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if s3m_note == S3M_NOTE_OFF:
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return NOTE_KEYOFF
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octave = (s3m_note >> 4) & 0xF
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pitch = s3m_note & 0xF
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if pitch > 11:
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return NOTE_NOP
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semitones = (octave - 4) * 12 + pitch
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val = round(TAUD_C3 + semitones * 4096 / 12)
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return max(1, min(0xFFFD, val))
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def encode_effect(cmd: int, arg: int, linear: bool) -> tuple:
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"""Return (taud_op, taud_arg16) or (0, 0) for no-op."""
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if cmd == EFF_D:
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# Volume slide: same nibble layout
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return (0x0A, arg & 0xFF)
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if cmd == EFF_E:
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# Porta down
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if linear:
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targ = min(arg * 4, 0xFFFF)
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else:
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targ = min(arg * 2, 0xFFFF)
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return (0x02, targ)
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if cmd == EFF_F:
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# Porta up
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if linear:
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targ = min(arg * 4, 0xFFFF)
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else:
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targ = min(arg * 2, 0xFFFF)
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return (0x01, targ)
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if cmd == EFF_S:
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sub = (arg >> 4) & 0xF
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val = arg & 0xF
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if sub == 0xC: # SC - note cut
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return (0xEC, val)
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return (0x00, 0x0000)
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# ── Taud builders ────────────────────────────────────────────────────────────
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def _resample_linear(data: bytes, ratio: float) -> bytes:
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"""Resample bytes by ratio (< 1 = downsample) using linear interpolation."""
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if not data:
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return data
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n_out = max(1, int(len(data) * ratio))
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out = bytearray(n_out)
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for i in range(n_out):
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src = i / ratio
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i0 = int(src)
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frac = src - i0
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i1 = min(i0 + 1, len(data) - 1)
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v = data[i0] * (1.0 - frac) + data[i1] * frac
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out[i] = int(v + 0.5) & 0xFF
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return bytes(out)
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def build_sample_inst_bin(instruments: list) -> tuple:
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"""
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Returns (bin_bytes[786432], offsets_list, updated_insts).
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Resamples globally if total exceeds SAMPLEBIN_SIZE.
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"""
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pcm_insts = [(i, inst) for i, inst in enumerate(instruments)
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if inst is not None and inst.itype == S3M_TYPE_PCM and inst.sample_data]
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total = sum(len(inst.sample_data) for _, inst in pcm_insts)
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ratio = 1.0
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if total > SAMPLEBIN_SIZE:
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ratio = SAMPLEBIN_SIZE / total
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vprint(f" info: sample bin overflow ({total} bytes); resampling all by {ratio:.4f}")
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for _, inst in pcm_insts:
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new_data = _resample_linear(inst.sample_data, ratio)
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old_len = len(inst.sample_data)
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inst.sample_data = new_data
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inst.length = len(new_data)
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inst.loop_begin = max(0, int(inst.loop_begin * ratio))
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inst.loop_end = max(0, min(int(inst.loop_end * ratio), inst.length))
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inst.c2spd = max(1, int(inst.c2spd * ratio))
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sample_bin = bytearray(SAMPLEBIN_SIZE)
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offsets = {}
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pos = 0
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for idx, inst in pcm_insts:
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n = min(len(inst.sample_data), SAMPLEBIN_SIZE - pos)
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if n <= 0:
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vprint(f" warning: sample bin full, dropping '{inst.name}'")
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offsets[idx] = 0
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inst.length = 0
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continue
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sample_bin[pos:pos+n] = inst.sample_data[:n]
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offsets[idx] = pos
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if n < len(inst.sample_data):
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vprint(f" warning: '{inst.name}' truncated from {len(inst.sample_data)} to {n}")
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inst.length = n
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inst.loop_end = min(inst.loop_end, n)
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pos += n
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# Build instrument bin (256 × 64 bytes)
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inst_bin = bytearray(INSTBIN_SIZE)
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for i, inst in enumerate(instruments):
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if i >= 256:
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break
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if inst is None or inst.itype != S3M_TYPE_PCM:
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continue
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ptr = offsets.get(i, 0)
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ptr_lo = ptr & 0xFFFF
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ptr_hi = (ptr >> 16)
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s_len = min(inst.length, 65535)
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c2spd = min(inst.c2spd, 65535)
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ps = 0
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ls = min(inst.loop_begin, 65535)
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le = min(inst.loop_end, 65535)
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loop_mode = 1 if (inst.flags & 1) else 0
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flags_byte = (ptr_hi << 4) | (loop_mode & 0x3) # hhhh 00pp
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base = i * 64
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struct.pack_into('<H', inst_bin, base + 0, ptr_lo)
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struct.pack_into('<H', inst_bin, base + 2, s_len)
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struct.pack_into('<H', inst_bin, base + 4, c2spd)
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struct.pack_into('<H', inst_bin, base + 6, ps)
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struct.pack_into('<H', inst_bin, base + 8, ls)
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struct.pack_into('<H', inst_bin, base + 10, le)
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inst_bin[base + 12] = flags_byte
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# Volume envelope: hold at instrument volume (vol*4 clamped to 255)
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env_vol = min(inst.volume * 4, 255)
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inst_bin[base + 16] = env_vol # volume
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inst_bin[base + 17] = 0 # offset minifloat = 0 → hold
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vprint(f" instrument '{inst.name}' ptr: '{ptr}', sampling rate: '{inst.c2spd}'")
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if inst.c2spd > 65535:
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vprint(f" warning: sampling rate of '{inst.name}' exceeds 65535 (got '{inst.c2spd}')")
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return bytes(sample_bin) + bytes(inst_bin), offsets
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def _default_channel_pan(ch_setting: int) -> int:
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"""Return Taud pan 0..63 from S3M channel-setting byte."""
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# Bits 4-7 of channel setting are ignored; left/right from bit 3
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# Actually the channel type (0-7 left, 8-15 right) encodes stereo side
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ch_type = ch_setting & 0x7F
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if 0 <= ch_type <= 7:
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return 16 # left
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elif 8 <= ch_type <= 15:
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return 47 # right
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return 31 # centre
|
||
|
||
|
||
def build_pattern(s3m_grid: list, ch_idx: int, default_pan: int,
|
||
linear_slides: bool) -> bytes:
|
||
"""Build a 512-byte Taud pattern for one S3M channel."""
|
||
out = bytearray(PATTERN_BYTES)
|
||
rows = s3m_grid[ch_idx] if ch_idx < len(s3m_grid) else [S3MRow()] * PATTERN_ROWS
|
||
for r, row in enumerate(rows[:PATTERN_ROWS]):
|
||
note = encode_note(row.note)
|
||
inst = max(0, row.inst - 1) # S3M 1-based → Taud 0-based
|
||
vol = min(row.vol, 63) if row.vol >= 0 else 63
|
||
pan = default_pan
|
||
op, arg = encode_effect(row.effect, row.effect_arg, linear_slides)
|
||
if row.effect != 0 and op == 0:
|
||
eff_name = chr(ord('A') + row.effect - 1) if 1 <= row.effect <= 26 else '?'
|
||
vprint(f" dropped effect {eff_name}{row.effect_arg:02X} at ch{ch_idx} row{r}")
|
||
base = r * 8
|
||
struct.pack_into('<H', out, base + 0, note)
|
||
out[base + 2] = inst & 0xFF
|
||
out[base + 3] = vol & 0x3F
|
||
out[base + 4] = pan & 0x3F
|
||
out[base + 5] = op & 0xFF
|
||
struct.pack_into('<H', out, base + 6, arg & 0xFFFF)
|
||
return bytes(out)
|
||
|
||
|
||
def deduplicate_patterns(pat_bin: bytes, num_pats: int) -> tuple:
|
||
"""
|
||
Consolidate identical 512-byte Taud patterns into a single copy.
|
||
Returns (deduped_bin, remap, num_unique) where remap[original_idx] = canonical_idx.
|
||
"""
|
||
seen = {} # pattern_bytes -> canonical_index
|
||
remap = {} # original_index -> canonical_index
|
||
canonical = []
|
||
for i in range(num_pats):
|
||
pat = pat_bin[i * PATTERN_BYTES : (i + 1) * PATTERN_BYTES]
|
||
if pat in seen:
|
||
remap[i] = seen[pat]
|
||
else:
|
||
ci = len(canonical)
|
||
seen[pat] = ci
|
||
remap[i] = ci
|
||
canonical.append(pat)
|
||
return b''.join(canonical), remap, len(canonical)
|
||
|
||
|
||
def _encode_cue(patterns12: list, instruction: int) -> bytearray:
|
||
"""Encode a 32-byte cue entry for up to 20 voices with 12-bit pattern numbers."""
|
||
# patterns12: list of up to NUM_VOICES 12-bit values (0xFFF = disabled)
|
||
pats = list(patterns12) + [0xFFF] * NUM_VOICES
|
||
pats = pats[:NUM_VOICES]
|
||
entry = bytearray(CUE_SIZE)
|
||
for i in range(10): # 10 bytes: 2 voices per byte
|
||
v0, v1 = pats[i*2], pats[i*2+1]
|
||
entry[i] = ((v0 & 0xF) << 4) | (v1 & 0xF) # low nybbles
|
||
entry[10 + i] = (((v0 >> 4) & 0xF) << 4) | ((v1 >> 4) & 0xF) # mid nybbles
|
||
entry[20 + i] = (((v0 >> 8) & 0xF) << 4) | ((v1 >> 8) & 0xF) # high nybbles
|
||
entry[30] = instruction & 0xFF
|
||
return entry
|
||
|
||
|
||
def build_cue_sheet(order_list: list, num_pats_s3m: int, num_channels: int,
|
||
pat_remap: dict = None) -> bytes:
|
||
"""Build the 1024×32-byte cue sheet with 12-bit packed pattern numbers."""
|
||
sheet = bytearray(NUM_CUES * CUE_SIZE)
|
||
# Fill entire sheet with the "all disabled" cue (patterns=0xFFF, instr=0)
|
||
for c in range(NUM_CUES):
|
||
sheet[c*CUE_SIZE : c*CUE_SIZE+CUE_SIZE] = _encode_cue([], 0)
|
||
|
||
cue_idx = 0
|
||
for order in order_list:
|
||
if order == S3M_ORDER_END or cue_idx >= NUM_CUES:
|
||
break
|
||
if order == S3M_ORDER_SKIP:
|
||
cue_idx += 1
|
||
continue
|
||
orig = [order * num_channels + v for v in range(num_channels)]
|
||
pats = [pat_remap[p] if pat_remap else p for p in orig]
|
||
sheet[cue_idx*CUE_SIZE : cue_idx*CUE_SIZE+CUE_SIZE] = _encode_cue(pats, 0)
|
||
cue_idx += 1
|
||
|
||
# Halt at end
|
||
if cue_idx < NUM_CUES:
|
||
sheet[cue_idx*CUE_SIZE : cue_idx*CUE_SIZE+CUE_SIZE] = _encode_cue([], 0x01)
|
||
|
||
return bytes(sheet)
|
||
|
||
|
||
def find_initial_bpm_speed(patterns: list, order_list: list,
|
||
default_speed: int, default_tempo: int) -> tuple:
|
||
"""Scan first pattern in order for Axx/Txx in row 0 of any channel."""
|
||
speed = default_speed or 6
|
||
tempo = default_tempo or 125
|
||
for order in order_list:
|
||
if order >= S3M_ORDER_END:
|
||
break
|
||
if order >= len(patterns):
|
||
continue
|
||
grid = patterns[order]
|
||
for ch_rows in grid:
|
||
row = ch_rows[0]
|
||
if row.effect == EFF_A and row.effect_arg > 0:
|
||
speed = row.effect_arg
|
||
if row.effect == EFF_T and row.effect_arg > 0:
|
||
tempo = row.effect_arg
|
||
break
|
||
return speed, tempo
|
||
|
||
|
||
def assemble_taud(h: S3MHeader, instruments: list, patterns: list) -> bytes:
|
||
# Determine active channels (bit7 clear = enabled)
|
||
active_channels = [i for i, cs in enumerate(h.channel_settings)
|
||
if i < 32 and not (cs & 0x80)][:NUM_VOICES]
|
||
C = len(active_channels)
|
||
P = len(patterns)
|
||
|
||
if P * C > NUM_PATTERNS_MAX:
|
||
sys.exit(
|
||
f"error: {P} S3M patterns × {C} channels = {P*C} > {NUM_PATTERNS_MAX} Taud pattern limit.\n"
|
||
f" Reduce the S3M to ≤ {NUM_PATTERNS_MAX // max(C,1)} patterns, or mute "
|
||
f"channels to bring active count below {NUM_PATTERNS_MAX // max(P,1) + 1}."
|
||
)
|
||
|
||
vprint(f" channels: {C}, s3m patterns: {P}, taud patterns: {P*C}")
|
||
|
||
# Build sample+instrument bin
|
||
vprint(" building sample/instrument bin…")
|
||
sampleinst_raw, _offsets = build_sample_inst_bin(instruments)
|
||
assert len(sampleinst_raw) == SAMPLEINST_SIZE
|
||
|
||
# Compress
|
||
compressed = gzip.compress(sampleinst_raw, compresslevel=9, mtime=0)
|
||
comp_size = len(compressed)
|
||
vprint(f" sample+inst bin: {SAMPLEINST_SIZE} → {comp_size} bytes (gzip)")
|
||
|
||
# Initial BPM / speed
|
||
speed, tempo = find_initial_bpm_speed(patterns, h.order_list,
|
||
h.initial_speed, h.initial_tempo)
|
||
tempo = max(24, min(280, tempo))
|
||
bpm_stored = (tempo - 24) & 0xFF
|
||
vprint(f" initial speed={speed}, tempo(BPM)={tempo}")
|
||
|
||
# Song offset = header(32) + compressed + song_table(8)
|
||
song_offset = TAUD_HEADER_SIZE + comp_size + TAUD_SONG_ENTRY
|
||
num_taud_pats = P * C
|
||
|
||
# Header (32 bytes): magic(8)+ver(1)+numSongs(1)+compSize(4)+rsvd(2)+sig(16)
|
||
sig = (SIGNATURE + b' ' * 16)[:16]
|
||
header = (
|
||
TAUD_MAGIC +
|
||
bytes([TAUD_VERSION, 1]) +
|
||
struct.pack('<I', comp_size) +
|
||
b'\x00\x00' +
|
||
sig
|
||
)
|
||
assert len(header) == TAUD_HEADER_SIZE
|
||
|
||
# Pattern bin: for each s3m pattern, for each active channel, 512 bytes
|
||
vprint(" building pattern bin…")
|
||
default_pans = [_default_channel_pan(h.channel_settings[ch]) for ch in active_channels]
|
||
pat_bin = bytearray()
|
||
for pi in range(P):
|
||
grid = patterns[pi]
|
||
for vi, ch in enumerate(active_channels):
|
||
pat_bin += build_pattern(grid, ch, default_pans[vi], h.linear_slides)
|
||
assert len(pat_bin) == num_taud_pats * PATTERN_BYTES
|
||
|
||
# Deduplicate identical patterns
|
||
vprint(" deduplicating patterns…")
|
||
orig_count = num_taud_pats
|
||
pat_bin, pat_remap, num_taud_pats = deduplicate_patterns(bytes(pat_bin), orig_count)
|
||
vprint(f" patterns: {orig_count} → {num_taud_pats} unique ({orig_count - num_taud_pats} deduplicated)")
|
||
|
||
# Song table row (16 bytes): offset(4)+voices(1)+patsLo(1)+patsHi(1)+bpm(1)+tick(1)+pad(7)
|
||
# Built after dedup so num_taud_pats reflects the unique count.
|
||
num_taud_pats_lo = num_taud_pats & 0xFF
|
||
num_taud_pats_hi = (num_taud_pats >> 8) & 0xFF
|
||
song_table = struct.pack('<IBBBBB',
|
||
song_offset,
|
||
C,
|
||
num_taud_pats_lo,
|
||
num_taud_pats_hi,
|
||
bpm_stored,
|
||
speed,
|
||
) + b'\x00' * 7
|
||
assert len(song_table) == TAUD_SONG_ENTRY
|
||
|
||
# Cue sheet (using remapped pattern indices)
|
||
vprint(" building cue sheet…")
|
||
cue_sheet = build_cue_sheet(h.order_list, P, C, pat_remap)
|
||
assert len(cue_sheet) == NUM_CUES * CUE_SIZE
|
||
|
||
return header + compressed + song_table + bytes(pat_bin) + cue_sheet
|
||
|
||
|
||
# ── Main ─────────────────────────────────────────────────────────────────────
|
||
|
||
def main():
|
||
global VERBOSE
|
||
ap = argparse.ArgumentParser(description=__doc__,
|
||
formatter_class=argparse.RawDescriptionHelpFormatter)
|
||
ap.add_argument('input', help='Input .s3m file')
|
||
ap.add_argument('output', help='Output .taud file')
|
||
ap.add_argument('-v', '--verbose', action='store_true',
|
||
help='Print conversion details to stderr')
|
||
args = ap.parse_args()
|
||
|
||
VERBOSE = args.verbose
|
||
|
||
with open(args.input, 'rb') as f:
|
||
data = f.read()
|
||
|
||
vprint(f"parsing '{args.input}' ({len(data)} bytes)…")
|
||
h = parse_s3m(data)
|
||
vprint(f" title: '{h.title}'")
|
||
vprint(f" orders={h.order_count}, instruments={h.inst_count}, patterns={h.pat_count}")
|
||
|
||
instruments = parse_instruments(data, h)
|
||
patterns = parse_patterns(data, h)
|
||
|
||
taud = assemble_taud(h, instruments, patterns)
|
||
|
||
with open(args.output, 'wb') as f:
|
||
f.write(taud)
|
||
|
||
print(f"wrote {len(taud)} bytes to '{args.output}'")
|
||
if VERBOSE:
|
||
print(f" magic ok: {taud[:8].hex()}", file=sys.stderr)
|
||
|
||
|
||
if __name__ == '__main__':
|
||
main()
|