nx_audio_lossless_gate.nx source

1// nx_audio_lossless_gate.nx -- MEASURES the two audio-SOTA claims the operator named ("audio where its 2// FLAC but with the dog hearing"): (1) LOSSLESS = bit-exact PCM round-trip through the sovereign LPC codec 3// (the FLAC guarantee: integer linear prediction + exactly-coded residuals, no quantization); (2) WIDE 4// SPECTRUM = a 30kHz "dog whistle" tone (human-inaudible >20kHz, dogs hear to ~45kHz) sampled at 96kHz 5// (Nyquist 48kHz) survives encode->decode UNFILTERED. Three signals stress all codec paths: a voice+ 6// ultrasonic tone mix (the headline), a predictable ramp (the LPC-compresses path), and pseudo-random 7// noise (the raw-fallback path). GREEN iff EVERY signal round-trips bit-exact (max-err = 0) -- proven, 8// not asserted. Reports the compression ratio vs raw PCM (the FLAC comparison). If any max-err != 0 the 9// codec is NOT lossless and this goes RED (measure, don't assume). expect_exit: 0 license_tier: ORIGINAL 10import "nx_syscalls.nx" 11import "nx_video_client_wasm.nx" // vc_lpc_encode / vc_lpc_decode / vc_lpc_rd_i16 / vc_lpc_wr_i16 12 13func aw(s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(1,s,n); return 0 } 14func an(v: i64) -> i64 { 15 let b: *u8=sys_mmap(28); var m: i64=v; if m<0{sys_write(1,"-" as *u8,1);m=0-m} 16 let t: *u8=sys_mmap(28); var k: i64=0; if m==0{t[0]=48 as u8;k=1} while m>0{t[k]=(48+(m%10)) as u8;m=m/10;k=k+1} 17 var i: i64=0; while i<k{b[i]=t[k-1-i];i=i+1} sys_write(1,b,k); return 0 } 18 19// 16-entry sine period, i16 amplitude ~+-8000 (one full cycle). step=1 -> 96000/16 = 6kHz (voice/audible); 20// step=5 -> 96000*5/16 = 30000 Hz = the 30kHz dog-audible ultrasonic tone. Both from ONE table. 21func sinei(k: i64) -> i64 { 22 let s: *i64 = sys_mmap(16*8) as *i64 23 s[0]=0; s[1]=3061; s[2]=5657; s[3]=7392; s[4]=8000; s[5]=7392; s[6]=5657; s[7]=3061 24 s[8]=0; s[9]=0-3061; s[10]=0-5657; s[11]=0-7392; s[12]=0-8000; s[13]=0-7392; s[14]=0-5657; s[15]=0-3061 25 return s[k & 15] 26} 27// write i16 LE into a byte buffer at sample index i 28func wr_s16(pcm: *u8, i: i64, v: i64) -> i64 { 29 pcm[i*2] = (v & 0xff) as u8 30 pcm[i*2+1] = ((v / 256) & 0xff) as u8 31 return 0 32} 33func rd_s16(pcm: *u8, i: i64) -> i64 { 34 var v: i64 = (pcm[i*2] as i64) + (pcm[i*2+1] as i64) * 256 35 if v >= 32768 { v = v - 65536 } 36 return v 37} 38 39// encode->decode roundtrip one signal; returns max abs sample error; sets bytes_out[0]=encoded bytes. 40func roundtrip(pcm: *u8, N: i64, out: *u8, back: *u8, scr: *i64, bytes_out: *i64) -> i64 { 41 let elen: i64 = vc_lpc_encode(pcm, N, out, N*2 + 4096, scr) 42 if elen < 0 { bytes_out[0] = elen; return 1000000 } 43 bytes_out[0] = elen 44 let dn: i64 = vc_lpc_decode(out, elen, back, N*2 + 4096, scr) 45 if dn != N { return 999999 } 46 var maxe: i64 = 0 47 var i: i64 = 0 48 while i < N { 49 let a: i64 = rd_s16(pcm, i) 50 let b: i64 = rd_s16(back, i) 51 var e: i64 = a - b 52 if e < 0 { e = 0 - e } 53 if e > maxe { maxe = e } 54 i = i + 1 55 } 56 return maxe 57} 58 59func main() -> i64 { 60 aw("=== nx_audio_lossless_gate: FLAC-class bit-exact + 30kHz dog-hearing retention (96kHz) ===\n" as *u8) 61 let N: i64 = 1024 62 let pcm: *u8 = sys_mmap(N*2 + 64) 63 let out: *u8 = sys_mmap(N*4 + 8192) 64 let back: *u8 = sys_mmap(N*2 + 8192) 65 let scr: *i64 = sys_mmap(N*8*4 + 8192) as *i64 66 let bo: *i64 = sys_mmap(16) as *i64 67 var bad: i64 = 0 68 69 // --- signal 1: 6kHz voice tone + 30kHz ultrasonic (the dog-whistle), @96kHz --- 70 var i: i64 = 0 71 while i < N { 72 var v: i64 = (sinei(i) / 2) + (sinei(i*5) / 3) // audible + ultrasonic, mixed, within i16 73 if v > 32767 { v = 32767 } 74 if v < 0-32768 { v = 0-32768 } 75 wr_s16(pcm, i, v) 76 i = i + 1 77 } 78 let e1: i64 = roundtrip(pcm, N, out, back, scr, bo) 79 let r1: i64 = (N*2*10) / bo[0] 80 aw(" [voice6k+ultrasonic30k @96kHz] enc=" as *u8); an(bo[0]); aw("B ratio=" as *u8); an(r1/10); aw("." as *u8); an(r1%10); aw("x max-err=" as *u8); an(e1) 81 if e1 == 0 { aw(" LOSSLESS (30kHz dog-tone survived bit-exact)\n" as *u8) } else { aw(" !!! LOSSY\n" as *u8); bad = bad + 1 } 82 83 // --- signal 2: predictable low-frequency ramp (the LPC-compresses path) --- 84 i = 0 85 while i < N { wr_s16(pcm, i, ((i * 24) & 0x3fff) - 8192); i = i + 1 } 86 let e2: i64 = roundtrip(pcm, N, out, back, scr, bo) 87 let r2: i64 = (N*2*10) / bo[0] 88 aw(" [predictable ramp] enc=" as *u8); an(bo[0]); aw("B ratio=" as *u8); an(r2/10); aw("." as *u8); an(r2%10); aw("x max-err=" as *u8); an(e2) 89 if e2 == 0 { aw(" LOSSLESS\n" as *u8) } else { aw(" !!! LOSSY\n" as *u8); bad = bad + 1 } 90 91 // --- signal 3: pseudo-random noise (the raw-fallback path -- incompressible) --- 92 var seed: i64 = 123456789 93 i = 0 94 while i < N { 95 seed = (seed * 1103515245 + 12345) & 0x7fffffff 96 wr_s16(pcm, i, (seed & 0xffff) - 32768) 97 i = i + 1 98 } 99 let e3: i64 = roundtrip(pcm, N, out, back, scr, bo) 100 let r3: i64 = (N*2*10) / bo[0] 101 aw(" [random noise] enc=" as *u8); an(bo[0]); aw("B ratio=" as *u8); an(r3/10); aw("." as *u8); an(r3%10); aw("x max-err=" as *u8); an(e3) 102 if e3 == 0 { aw(" LOSSLESS\n" as *u8) } else { aw(" !!! LOSSY\n" as *u8); bad = bad + 1 } 103 104 aw(" SPECTRUM: 96kHz sample rate -> Nyquist 48kHz covers canine hearing (~45kHz); bit-exact => the\n" as *u8) 105 aw(" 30kHz tone (human-inaudible, dog-audible) is retained UNFILTERED end to end.\n" as *u8) 106 if bad == 0 { aw("AUDIO-LOSSLESS-GATE verdict=GREEN -- FLAC-class lossless + wide-spectrum PROVEN (all 3 paths bit-exact)\n" as *u8); return 0 } 107 aw("AUDIO-LOSSLESS-GATE verdict=RED -- codec is NOT bit-exact on " as *u8); an(bad); aw(" signal(s); lossless claim FALSE\n" as *u8) 108 return 1 109}