rustytorch/crates/models/rtx-csm/examples/silentcipher_smoke.rs

//! Phase 10.3 smoke test for SilentCipher embed. Downloads the
//! 16 kHz checkpoint from `sony/silentcipher`, loads all 3 networks,
//! runs the encode pipeline on a synthetic sine + a real speech clip,
//! verifies the output preserves shape + has signal.
//!
//! Stops short of detection (Phase 10.4 will add detect + ship the
//! Watermarker trait impl).
//!
//! Usage:
//! ```bash
//! cargo run -p rtx-csm --release --features metal --example silentcipher_smoke
//! ```

use anyhow::{Context, Result};
use candle_core::Device;
use hf_hub::api::sync::Api;
use rtx_csm::silentcipher::{SilentCipherConfig, SilentCipherWatermarker};
use std::time::Instant;

const REPO: &str = "sony/silentcipher";
const CKPT_DIR: &str = "16_khz/97561_iteration";

fn main() -> Result<()> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::WARN)
        .init();

    let device = if candle_core::utils::metal_is_available() {
        Device::new_metal(0)?
    } else {
        Device::Cpu
    };
    eprintln!("device: {device:?}");

    // Download the 3 ckpts + hparams.
    let api = Api::new()?;
    let repo = api.model(REPO.to_string());
    let enc_c = repo
        .get(&format!("{CKPT_DIR}/enc_c.ckpt"))
        .context("download enc_c.ckpt")?;
    let dec_c = repo
        .get(&format!("{CKPT_DIR}/dec_c.ckpt"))
        .context("download dec_c.ckpt")?;
    let dec_m_0 = repo
        .get(&format!("{CKPT_DIR}/dec_m_0.ckpt"))
        .context("download dec_m_0.ckpt")?;
    eprintln!("downloaded: {}", enc_c.parent().unwrap().display());

    // Construct.
    let cfg = SilentCipherConfig::sixteen_khz();
    let load_t = Instant::now();
    let wm = SilentCipherWatermarker::from_ckpts(cfg, &enc_c, &dec_c, &dec_m_0, &device)?;
    eprintln!("watermarker built in {} ms", load_t.elapsed().as_millis());

    // Synthetic 1 s 440 Hz sine at 16 kHz.
    let n = 16_000;
    let samples: Vec<f32> = (0..n)
        .map(|i| {
            (2.0 * std::f32::consts::PI * 440.0 * i as f32 / 16_000.0).sin() * 0.3
        })
        .collect();
    eprintln!();
    eprintln!("=== synthetic sine ===");
    eprintln!("input samples: {}", samples.len());

    // 16 kHz model carries ~23.78 bits per patch (15 base-3 codes).
    // Pick a payload that's well below 3^15 = 14_348_907.
    let payload = 12345678u32;
    let codes = wm.encode_bits(payload);
    eprintln!(
        "payload 0x{payload:08X} -> {} codes (each in 0..{}): {:?}",
        codes.len(),
        wm.cfg.message_dim,
        &codes
    );

    let t = Instant::now();
    let watermarked = wm
        .embed(&samples, &codes)
        .context("embed sine")?;
    let embed_ms = t.elapsed().as_millis();
    eprintln!(
        "embed: {embed_ms} ms ({} samples in / {} samples out)",
        samples.len(),
        watermarked.len()
    );

    // Sanity: shape preserved + samples differ from original (watermark
    // present) but not catastrophically.
    assert_eq!(
        samples.len(),
        watermarked.len(),
        "embed must preserve length"
    );
    let diff_rms: f32 = samples
        .iter()
        .zip(watermarked.iter())
        .map(|(a, b)| (a - b).powi(2))
        .sum::<f32>()
        .sqrt()
        / (samples.len() as f32).sqrt();
    let orig_rms: f32 =
        (samples.iter().map(|&s| s * s).sum::<f32>() / samples.len() as f32).sqrt();
    let ratio = diff_rms / orig_rms;
    eprintln!(
        "RMS diff vs original: {diff_rms:.5}  (orig RMS {orig_rms:.4}, ratio {ratio:.4})"
    );
    if ratio < 1e-5 {
        println!("WARN: watermark RMS is near-zero — model may not be loading correctly");
    } else if ratio > 0.5 {
        println!("WARN: watermark RMS is huge — corruption likely");
    } else {
        println!("PASS: shape preserved + watermark added (ratio {ratio:.4})");
    }

    // Try a real speech clip if /tmp/asr_test.flac exists.
    let asr_path = std::path::Path::new("/tmp/asr_test.flac");
    if asr_path.exists() {
        eprintln!();
        eprintln!("=== real speech (/tmp/asr_test.flac) ===");
        let speech = rtx_csm::audio_io::load_mono_at_rate(asr_path, 16_000)?;
        eprintln!("input samples: {} ({:.2}s)", speech.len(), speech.len() as f32 / 16_000.0);
        let t = Instant::now();
        let watermarked = wm.embed(&speech, &codes).context("embed speech")?;
        let speech_ms = t.elapsed().as_millis();
        eprintln!(
            "embed: {speech_ms} ms ({:.2}× realtime)",
            speech_ms as f32 / (speech.len() as f32 / 16_000.0 * 1000.0)
        );
        let diff_rms: f32 = speech
            .iter()
            .zip(watermarked.iter())
            .map(|(a, b)| (a - b).powi(2))
            .sum::<f32>()
            .sqrt()
            / (speech.len() as f32).sqrt();
        let orig_rms: f32 = (speech.iter().map(|&s| s * s).sum::<f32>()
            / speech.len() as f32)
            .sqrt();
        let snr_db = 20.0 * (orig_rms / diff_rms.max(1e-12)).log10();
        println!("speech embed: SNR vs original = {snr_db:.1} dB (target ~47 dB per hparams)");
        // Save the output WAV for ear test.
        rtx_csm::audio_io::write_wav_mono(
            std::path::Path::new("/tmp/silentcipher_smoke.wav"),
            &watermarked,
            16_000,
        )?;
        eprintln!("wrote /tmp/silentcipher_smoke.wav for ear test");

        // Phase 10.4 round-trip: detect on the watermarked audio,
        // verify we recover the embedded codes.
        let detect_t = Instant::now();
        let result = wm.detect(&watermarked).context("detect speech")?;
        let detect_ms = detect_t.elapsed().as_millis();
        eprintln!();
        eprintln!("=== detect round-trip ===");
        eprintln!(
            "detect: {detect_ms} ms ({:.4}× realtime)",
            detect_ms as f32 / (speech.len() as f32 / 16_000.0 * 1000.0)
        );
        eprintln!("recovered codes:    {:?}", result.codes);
        eprintln!("confidence:         {:.3}", result.confidence);
        let recovered_payload = wm.decode_bits(&result.codes);
        eprintln!("recovered payload:  0x{recovered_payload:08X}");
        eprintln!("expected payload:   0x{payload:08X}");
        let matching_codes = result
            .codes
            .iter()
            .zip(codes.iter())
            .filter(|(a, b)| a == b)
            .count();
        eprintln!(
            "matching codes:     {} / {} ({:.1}%)",
            matching_codes,
            codes.len(),
            100.0 * matching_codes as f32 / codes.len() as f32
        );
        if matching_codes == codes.len() {
            println!("PASS: full round-trip recovers the embedded payload");
        } else if matching_codes >= codes.len() * 3 / 4 {
            println!("PARTIAL: most codes recovered ({matching_codes}/{}); good enough for confidence-based detection", codes.len());
        } else {
            println!(
                "WEAK: only {matching_codes}/{} codes recovered. Likely a normalization bug (Phase 10.5 to fix)",
                codes.len()
            );
        }

        // Also detect on UN-watermarked audio — should NOT recover the
        // payload (or low confidence).
        let result_clean = wm.detect(&speech).context("detect clean")?;
        eprintln!();
        eprintln!("=== detect on un-watermarked audio ===");
        eprintln!("recovered codes:    {:?}", result_clean.codes);
        eprintln!("confidence:         {:.3}", result_clean.confidence);
        let clean_matching = result_clean
            .codes
            .iter()
            .zip(codes.iter())
            .filter(|(a, b)| a == b)
            .count();
        if clean_matching < codes.len() / 2 {
            println!(
                "PASS: clean audio does NOT recover the payload ({clean_matching}/{} match)",
                codes.len()
            );
        } else {
            println!(
                "WARN: clean audio matches {clean_matching}/{} codes — confidence threshold needed for false-positive control",
                codes.len()
            );
        }
    }
    Ok(())
}