nx_nv1_lpc_gate.nx source

1// nx_nv1_lpc_gate.nx -- ENGINEER gate for the NV1 LPC rung (nx_nv1_lpc.nx). 2// Evidence-driven, re-runnable, no network. Proves: 3// 1. BIT-EXACT round-trip (decode(encode(x)) == x byte-for-byte) on every 4// signal class: silence, DC, ramp, triangle, full-range LCG noise, 5// speech-ish (triangle + dither), alternating extremes, tiny blocks. 6// 2. FLAC-CLASS compression measured in permil of raw bytes (asserted 7// ceilings per class; printed so the ratio is ON the log). 8// 3. The verbatim escape: noise NEVER expands past 6 + 2n. 9// 4. Container integration: an 'L' chunk validates under nv1_validate 10// and its samples are counted. 11// 5. Every decoder rejection class fires its named negative. 12// license_tier: ORIGINAL 13 14import "nx_nv1_lpc.nx" 15import "nx_g_check_lib.nx" 16import "nx_g_puts_lib.nx" 17 18func g_dec(v: i64) -> i64 { 19 let d: *u8 = sys_mmap(32) 20 let t: *u8 = sys_mmap(32) 21 if v == 0 { d[0] = 48 as u8; sys_write(1, d, 1); return 0 } 22 var x: i64 = v 23 var n: i64 = 0 24 while x > 0 { t[n] = (48 + x % 10) as u8; x = x / 10; n = n + 1 } 25 var i: i64 = 0 26 while i < n { d[i] = t[n - 1 - i]; i = i + 1 } 27 sys_write(1, d, n) 28 return 0 29} 30 31// encode -> decode -> byte-compare; returns payload len, or a negative 32// (-100x encode fail, -200 wrong count, -300 byte mismatch) 33func g_rt(pcm: *u8, n: i64, pay: *u8, dec: *u8) -> i64 { 34 let el: i64 = nv1l_encode(pcm, n, pay, 6 + 2 * n + 64) 35 if el < 0 { return 0 - 1000 + el } 36 let dn: i64 = nv1l_decode(pay, el, dec, 2 * n + 64) 37 if dn != n { return 0 - 200 } 38 var i: i64 = 0 39 var ok: i64 = 1 40 while i < 2 * n { 41 if dec[i] != pcm[i] { ok = 0; i = 2 * n } else { i = i + 1 } 42 } 43 if ok == 0 { return 0 - 300 } 44 return el 45} 46 47func g_wr_i16(b: *u8, idx: i64, v: i64) -> i64 { 48 var u: i64 = v 49 if u < 0 { u = u + 65536 } 50 b[idx * 2] = (u & 255) as u8 51 b[idx * 2 + 1] = ((u / 256) & 255) as u8 52 return 0 53} 54 55// triangle wave sample: amp ~8128, period 256 (corner-rich = LPC stress) 56func g_tri(i: i64) -> i64 { 57 let ph: i64 = i % 256 58 if ph >= 128 { return 8128 - (ph - 128) * 127 } 59 return ph * 127 - 8128 60} 61 62func g_ratio_line(name: *u8, paylen: i64, rawlen: i64) -> i64 { 63 g_puts(" RATIO " as *u8); g_puts(name) 64 g_puts(" payload=" as *u8); g_dec(paylen) 65 g_puts("B raw=" as *u8); g_dec(rawlen) 66 g_puts("B permil=" as *u8); g_dec((paylen * 1000) / rawlen) 67 g_puts("\n" as *u8) 68 return (paylen * 1000) / rawlen 69} 70 71func main() -> i64 { 72 g_puts("nx_nv1_lpc gate (NV1 FLAC-class LPC rung)\n" as *u8) 73 var pass: i64 = 0 74 var total: i64 = 0 75 let N: i64 = 4096 76 let pcm: *u8 = sys_mmap(2 * N + 64) 77 let pay: *u8 = sys_mmap(2 * N + 256) 78 let dec: *u8 = sys_mmap(2 * N + 256) 79 var i: i64 = 0 80 var el: i64 = 0 81 var pm: i64 = 0 82 83 // ---- 1. silence ---- 84 i = 0 85 while i < 2 * N { pcm[i] = 0 as u8; i = i + 1 } 86 el = g_rt(pcm, N, pay, dec) 87 pass = pass + g_check("silence round-trip bit-exact" as *u8, el > 0) 88 total = total + 1 89 pm = g_ratio_line("silence" as *u8, el, 2 * N) 90 pass = pass + g_check("silence permil <= 120" as *u8, pm <= 120) 91 total = total + 1 92 93 // ---- 2. DC 1000 ---- 94 i = 0 95 while i < N { g_wr_i16(pcm, i, 1000); i = i + 1 } 96 el = g_rt(pcm, N, pay, dec) 97 pass = pass + g_check("DC round-trip bit-exact" as *u8, el > 0) 98 total = total + 1 99 100 // ---- 3. ramp (order-2 territory) ---- 101 i = 0 102 while i < N { g_wr_i16(pcm, i, i * 8 - 16384); i = i + 1 } 103 el = g_rt(pcm, N, pay, dec) 104 pass = pass + g_check("ramp round-trip bit-exact" as *u8, el > 0) 105 total = total + 1 106 var predicted: i64 = 0 107 if el > 0 { if (pay[0] & 0xff) != 255 { predicted = 1 } } 108 pass = pass + g_check("ramp uses a predictor (mode != verbatim)" as *u8, predicted) 109 total = total + 1 110 pm = g_ratio_line("ramp" as *u8, el, 2 * N) 111 pass = pass + g_check("ramp permil <= 100" as *u8, pm <= 100) 112 total = total + 1 113 114 // ---- 4. triangle wave (corner-rich; ~311 permil expected) ---- 115 i = 0 116 while i < N { g_wr_i16(pcm, i, g_tri(i)); i = i + 1 } 117 el = g_rt(pcm, N, pay, dec) 118 pass = pass + g_check("triangle round-trip bit-exact" as *u8, el > 0) 119 total = total + 1 120 pm = g_ratio_line("triangle" as *u8, el, 2 * N) 121 pass = pass + g_check("triangle permil <= 400" as *u8, pm <= 400) 122 total = total + 1 123 124 // ---- 5. full-range LCG noise: verbatim escape, never expands ---- 125 var seed: i64 = 12345 126 i = 0 127 while i < N { 128 seed = (seed * 1103515245 + 12345) & 0x7fffffff 129 g_wr_i16(pcm, i, ((seed >> 8) % 65536) - 32768) 130 i = i + 1 131 } 132 el = g_rt(pcm, N, pay, dec) 133 pass = pass + g_check("noise round-trip bit-exact" as *u8, el > 0) 134 total = total + 1 135 pass = pass + g_check("noise never expands (<= 6 + 2n)" as *u8, el <= 6 + 2 * N) 136 total = total + 1 137 138 // ---- 6. speech-ish: triangle + small dither ---- 139 seed = 777 140 i = 0 141 while i < N { 142 seed = (seed * 1103515245 + 12345) & 0x7fffffff 143 g_wr_i16(pcm, i, g_tri(i) + ((seed >> 8) & 127) - 64) 144 i = i + 1 145 } 146 el = g_rt(pcm, N, pay, dec) 147 pass = pass + g_check("speech-ish round-trip bit-exact" as *u8, el > 0) 148 total = total + 1 149 pm = g_ratio_line("speechish" as *u8, el, 2 * N) 150 pass = pass + g_check("speech-ish permil <= 700 (FLAC-class)" as *u8, pm <= 700) 151 total = total + 1 152 153 // ---- 7. alternating extremes (zigzag/k stress) ---- 154 i = 0 155 while i < N { 156 var av: i64 = 32767 157 if (i & 1) == 1 { av = 0 - 32768 } 158 g_wr_i16(pcm, i, av) 159 i = i + 1 160 } 161 el = g_rt(pcm, N, pay, dec) 162 pass = pass + g_check("alternating extremes bit-exact" as *u8, el > 0) 163 total = total + 1 164 165 // ---- 8. tiny blocks n=1,2,3 ---- 166 var tiny: i64 = 1 167 g_wr_i16(pcm, 0, 0 - 12345) 168 g_wr_i16(pcm, 1, 31000) 169 g_wr_i16(pcm, 2, 0 - 1) 170 var tn: i64 = 1 171 while tn < 4 { 172 if g_rt(pcm, tn, pay, dec) < 0 { tiny = 0 } 173 tn = tn + 1 174 } 175 pass = pass + g_check("tiny blocks n=1,2,3 bit-exact" as *u8, tiny) 176 total = total + 1 177 178 // ---- 9. n=0 ---- 179 el = nv1l_encode(pcm, 0, pay, 64) 180 var z: i64 = 0 181 if el == 6 { if nv1l_decode(pay, 6, dec, 64) == 0 { z = 1 } } 182 pass = pass + g_check("empty block encodes to 6B, decodes to 0" as *u8, z) 183 total = total + 1 184 185 // ---- 10. container: L chunk validates + samples counted ---- 186 i = 0 187 while i < 1024 { g_wr_i16(pcm, i, g_tri(i)); i = i + 1 } 188 el = nv1l_encode(pcm, 1024, pay, 6 + 2048 + 64) 189 let cbuf: *u8 = sys_mmap(65536) 190 var w: i64 = nv1_write_header(cbuf, 48000) 191 w = nv1_write_chunk(cbuf, w, 76, 0, pay, el) 192 w = nv1_write_end(cbuf, w, 21) 193 let info: *i64 = sys_mmap(64) as *i64 194 var rc: i64 = nv1_validate(cbuf, w, info) 195 var cok: i64 = 0 196 if rc == 0 { if info[1] == 1 { if info[2] == 1024 { cok = 1 } } } 197 pass = pass + g_check("container with L chunk: rc=0, 1024 samples counted" as *u8, cok) 198 total = total + 1 199 200 // L chunk with len < 6 sub-header -> -9 201 w = nv1_write_header(cbuf, 48000) 202 w = nv1_write_chunk(cbuf, w, 76, 0, pay, 4) 203 w = nv1_write_end(cbuf, w, 1) 204 rc = nv1_validate(cbuf, w, info) 205 pass = pass + g_check("L chunk shorter than sub-header -> -9" as *u8, rc == 0 - 9) 206 total = total + 1 207 208 // ---- 11. decoder rejection classes ---- 209 rc = nv1l_decode(pay, 5, dec, 8192) 210 pass = pass + g_check("payload < 6 -> -1" as *u8, rc == 0 - 1) 211 total = total + 1 212 213 // rebuild a known-good payload (triangle 1024 from above is in pay/el) 214 let save0: i64 = pay[0] & 0xff 215 pay[0] = 7 as u8 216 rc = nv1l_decode(pay, el, dec, 8192) 217 pass = pass + g_check("bad mode 7 -> -2" as *u8, rc == 0 - 2) 218 total = total + 1 219 pay[0] = save0 as u8 220 221 let save1: i64 = pay[1] & 0xff 222 pay[1] = 31 as u8 223 rc = nv1l_decode(pay, el, dec, 8192) 224 pass = pass + g_check("k=31 -> -3" as *u8, rc == 0 - 3) 225 total = total + 1 226 pay[1] = save1 as u8 227 228 rc = nv1l_decode(pay, el, dec, 100) 229 pass = pass + g_check("output cap overrun -> -4" as *u8, rc == 0 - 4) 230 total = total + 1 231 232 rc = nv1l_decode(pay, el / 2, dec, 8192) 233 pass = pass + g_check("truncated bitstream -> -5" as *u8, rc == 0 - 5) 234 total = total + 1 235 236 // mode >= nsamples -> -6 (hand-built: mode 3, ns 2) 237 pay[0] = 3 as u8 238 pay[1] = 0 as u8 239 nv1_wr_u32(pay, 2, 2) 240 rc = nv1l_decode(pay, 16, dec, 8192) 241 pass = pass + g_check("order >= nsamples -> -6" as *u8, rc == 0 - 6) 242 total = total + 1 243 244 // out-of-range reconstruction -> -7 (mode 1, k 0, ns 2, warmup 32767, 245 // residual +1 => 32768): bitstream u=2 (LSB-first 1,1,0) = 0x03 246 pay[0] = 1 as u8 247 pay[1] = 0 as u8 248 nv1_wr_u32(pay, 2, 2) 249 g_wr_i16(pay, 3, 32767) // warmup at byte offset 6 = idx 3 250 pay[8] = 3 as u8 251 rc = nv1l_decode(pay, 9, dec, 8192) 252 pass = pass + g_check("out-of-range reconstruction -> -7 (tamper-evident)" as *u8, rc == 0 - 7) 253 total = total + 1 254 255 // verbatim shorter than claimed -> -6 256 pay[0] = 255 as u8 257 pay[1] = 0 as u8 258 nv1_wr_u32(pay, 2, 100) 259 rc = nv1l_decode(pay, 50, dec, 8192) 260 pass = pass + g_check("verbatim shorter than claimed -> -6" as *u8, rc == 0 - 6) 261 total = total + 1 262 263 g_puts("---- nv1_lpc gate: passed " as *u8) 264 g_dec(pass) 265 g_puts(" / " as *u8) 266 g_dec(total) 267 g_puts(" ----\n" as *u8) 268 if pass == total { return 0 } 269 return 1 270}