Measure real CPU VAD on complete frozen media pool

docs/SPEECH-VAD.md

@@ -2,7 +2,8 @@
 
 Research recorded 2026-10-13 against whisper.cpp **v1.9.5**, exact commit
 `d1be6fde11ac6e0407606b4e42fe72d34add8037`. A real-model CPU silence contract
-check has now passed; no media comparison, alignment experiment, product
+check and complete five-source VAD run have now passed; no gated ASR comparison,
+alignment experiment, product
 integration or default change has been performed. The
 corrected ungated ASR observations remain in [speech alignment](SPEECH-ALIGNMENT.md).
 The instrumental piano's large CPU cost and unrelated text motivate testing;
@@ -183,6 +184,38 @@ parameter table, catches native error-level logs, and checks probability frame
 coverage. This is a smoke test, not a speech-quality result or OS thread-count
 measurement. An independent complete media comparison remains necessary.
 
+## Complete frozen-pool VAD measurement
+
+The tracked `tools/speech-vad/run.py` verified every source hash and primary
+audio stream, decoded float PCM with full sample coverage, and ran the v6.2.0
+candidate over all five existing competitors. Raw probabilities/logs and both
+raw and source-intersected intervals are retained in ignored
+`.searchi/speech/vad-v6-results.json`, SHA-256
+`093be2005b57fe16a8f85161cc9da8966e70e2050cf19fa4122531e304dd70df`.
+Current diagnostic worker SHA-256:
+`28746d770ed470d13475d9474fcd37f28c38c39f27da09219bf9a15eef2adb19`.
+
+| Source | Intervals | Detected source seconds | Whole VAD process ms |
+| --- | ---: | ---: | ---: |
+| clip04 (speech) | 12 | 66.04 | 2002.7 |
+| music01 | 0 | 0 | 870.1 |
+| music02 | 0 | 0 | 160.1 |
+| sound01 | 0 | 0 | 57.7 |
+| sound02 | 0 | 0 | 108.3 |
+
+The first attempted run rejected finite float decoder overshoot above unity.
+That input contract was incorrect: float decoding can exceed unity without
+corruption. The wrapper now preserves finite samples without clipping and
+rejects nonfinite values. The failure log was retained and no reduced pool
+was scored. All three native contracts passed again with the corrected build;
+four mapping regressions cover centiseconds, source origin, padded tails and
+invalid intervals. Segmentation parameters and model remained frozen.
+
+This small VAD-only result supports testing gated ASR next. It does not establish
+speech recall, transcript correctness, timestamp accuracy, retrieval improvement
+or a general music policy. No production gate was added and original Google
+audio retrieval remains unchanged.
+
 Open gates: actual one-thread audit, detection/recognition
 comparison, ordinary and DTW timestamp regression, independent held-out quality,
 background starvation/cancellation/crash recovery, packaging/license review,

tools/speech-vad/README.md

@@ -12,7 +12,8 @@ cmake --build .searchi/speech/build-vad-diagnostic --config Release --parallel 1
 Run `searchi-vad-diagnostic MODEL PCM_F32LE`, retaining stdout and stderr
 separately. Independently verify the model SHA-256 before running. Input must
 be verified mono 16-kHz little-endian float32 PCM, at most ten minutes, with
-finite normalized samples. CPU and one inference thread are fixed. Native error
+finite samples. Decoder overshoot beyond unity is preserved without clipping.
+CPU and one inference thread are fixed. Native error
 logs invalidate detection even when upstream returns success. Probability
 count must match the pinned 512-sample inference framing.
 

tools/speech-vad/diagnostic.cpp

@@ -31,7 +31,9 @@ int main(int argc, char ** argv) {
     std::vector<float> samples(static_cast<size_t>(bytes) / 4);
     input.seekg(0);
     if (!input.read(reinterpret_cast<char *>(samples.data()), bytes)) return 2;
-    for (float sample : samples) if (!std::isfinite(sample) || std::abs(sample) > 1.0f) return 2;
+    // Float decoding may legitimately overshoot unity. Preserve source samples;
+    // clipping would change the experiment. Reject nonfinite input only.
+    for (float sample : samples) if (!std::isfinite(sample)) return 2;
     whisper_log_set(log_message, nullptr);
     auto context_params = whisper_vad_default_context_params();
     context_params.n_threads = 1;

tools/speech-vad/run.py

@@ -0,0 +1,85 @@
+"""Frozen complete media-pool CPU VAD experiment; no ASR or ranking changes."""
+import argparse
+import importlib.util
+import json
+from pathlib import Path
+import tempfile
+
+spec = importlib.util.spec_from_file_location("speech_contract", Path(__file__).parents[1] / "speech-eval/run.py")
+speech = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(speech)
+MODEL_SHA = "2aa269b785eeb53a82983a20501ddf7c1d9c48e33ab63a41391ac6c9f7fb6987"
+
+
+def source_intersection(interval, samples, origin_ms):
+    start, end = interval
+    if start < 0 or end <= start or int(start) != start or int(end) != end:
+        raise ValueError("Invalid raw centisecond interval")
+    raw_start, raw_end = int(start) * 160, int(end) * 160
+    bounded_start, bounded_end = min(raw_start, samples), min(raw_end, samples)
+    return {"raw_cs": interval, "source_samples": [bounded_start, bounded_end],
+            "source_absolute_ms": [origin_ms + bounded_start / 16, origin_ms + bounded_end / 16],
+            "tail_padding_samples": max(0, raw_end - samples)}
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    for option in ("worker", "model", "ffmpeg", "ffprobe", "output", "scratch-parent"):
+        parser.add_argument("--" + option, type=Path, required=True)
+    parser.add_argument("--worker-sha256", required=True)
+    parser.add_argument("--fixture", type=Path, default=Path("fixtures/media/fixture.json"))
+    args = parser.parse_args()
+    if args.output.exists():
+        raise ValueError("Never overwrite experiment evidence")
+    if speech.sha256(args.worker) != args.worker_sha256 or speech.sha256(args.model) != MODEL_SHA:
+        raise ValueError("Frozen worker/model mismatch")
+    if speech.sha256(args.fixture) != speech.FIXTURE_SHA:
+        raise ValueError("Frozen media fixture mismatch")
+    fixture = json.loads(args.fixture.read_text(encoding="utf-8"))
+    selected = [asset for asset in fixture["assets"] if asset["id"] in speech.ASSETS]
+    if sorted(asset["id"] for asset in selected) != sorted(speech.ASSETS):
+        raise ValueError("Incomplete or duplicate competitor pool")
+    rows = []
+    args.scratch_parent.mkdir(parents=True, exist_ok=True)
+    with tempfile.TemporaryDirectory(prefix="vad-proof-", dir=args.scratch_parent) as scratch_dir:
+        scratch = Path(scratch_dir)
+        for asset in selected:
+            source = args.fixture.parent / asset["path"]
+            if source.stat().st_size != asset["bytes"] or speech.sha256(source) != asset["sha256"]:
+                raise ValueError("Frozen source mismatch")
+            probe_ms = speech.run_owned([str(args.ffprobe.resolve()), "-v", "error", "-protocol_whitelist", "file,pipe",
+                "-show_entries", "stream=index,codec_type,duration,start_time", "-of", "json", str(source.resolve())], scratch, "probe", [], 30)
+            probe = json.loads((scratch / "probe.log").read_text(encoding="utf-8"))
+            start, end, index = speech.primary_audio_range(probe)
+            pcm = scratch / "audio.f32"
+            command = speech.decode_command(args.ffmpeg, source, start, end - start, pcm, index)
+            command[command.index("pcm_s16le")] = "pcm_f32le"
+            command[-1:-1] = ["-f", "f32le"]
+            decode_ms = speech.run_owned(command, scratch, "decode", [(pcm, 16000 * 600 * 4)], 60)
+            samples = pcm.stat().st_size // 4
+            if pcm.stat().st_size % 4 or abs(samples - (end - start) * 16) > 16:
+                raise ValueError("Incomplete decoded coverage")
+            process_ms = speech.run_owned([str(args.worker.resolve()), str(args.model.resolve()), str(pcm)], scratch, "vad", [], 120)
+            log = (scratch / "vad.log").read_text(encoding="utf-8")
+            report = json.loads(log.strip().splitlines()[-1])
+            if report["samples"] != samples or report["threads"] != 1 or report["gpu"] is not False:
+                raise ValueError("Unexpected native contract")
+            if source.stat().st_size != asset["bytes"] or speech.sha256(source) != asset["sha256"]:
+                raise ValueError("Source changed during detection")
+            rows.append({"asset": asset["id"], "source_sha256": asset["sha256"], "probe": probe,
+                         "probe_ms": probe_ms, "decode_ms": decode_ms, "process_ms": process_ms,
+                         "native": report, "native_log": log,
+                         "intervals": [source_intersection(interval, samples, start) for interval in report["intervals_cs"]]})
+    result = {"schema": 1, "complete": True, "scope": "VAD only; no ASR quality or retrieval claim",
+              "fixture_sha256": speech.FIXTURE_SHA, "worker_sha256": args.worker_sha256,
+              "model_sha256": MODEL_SHA, "harness_sha256": speech.sha256(Path(__file__)),
+              "speech_contract_sha256": speech.sha256(Path(spec.origin)),
+              "ffmpeg_sha256": speech.sha256(args.ffmpeg), "ffprobe_sha256": speech.sha256(args.ffprobe), "rows": rows}
+    args.output.parent.mkdir(parents=True, exist_ok=True)
+    with args.output.open("x", encoding="utf-8") as stream:
+        json.dump(result, stream, indent=2)
+        stream.write("\n")
+
+
+if __name__ == "__main__":
+    main()

tools/speech-vad/test_mapping.py

@@ -0,0 +1,27 @@
+import unittest
+from run import source_intersection
+
+
+class Mapping(unittest.TestCase):
+    def test_units_and_nonzero_origin_once(self):
+        interval = source_intersection([10, 25], 16000, 5125)
+        self.assertEqual(interval["source_samples"], [1600, 4000])
+        self.assertEqual(interval["source_absolute_ms"], [5225, 5375])
+
+    def test_padded_tail_keeps_raw_evidence(self):
+        interval = source_intersection([90, 102], 16001, 0)
+        self.assertEqual(interval["raw_cs"], [90, 102])
+        self.assertEqual(interval["source_samples"], [14400, 16001])
+        self.assertEqual(interval["tail_padding_samples"], 319)
+
+    def test_synthetic_only_interval_has_empty_source_intersection(self):
+        self.assertEqual(source_intersection([101, 102], 16001, 0)["source_samples"], [16001, 16001])
+
+    def test_bad_units_and_order_fail(self):
+        for interval in ([0.1, 2], [-1, 2], [2, 2], [3, 2]):
+            with self.subTest(interval=interval), self.assertRaises(ValueError):
+                source_intersection(interval, 16000, 0)
+
+
+if __name__ == "__main__":
+    unittest.main()

tools/speech-vad/test_native.py

@@ -37,7 +37,7 @@ class NativeContract(unittest.TestCase):
             self.assertGreaterEqual(report[key], 0)
 
     def test_invalid_pcm(self):
-        for data in (b"", b"x", struct.pack("<f", float("nan")), struct.pack("<f", 2)):
+        for data in (b"", b"x", struct.pack("<f", float("nan")), struct.pack("<f", float("inf"))):
             with self.subTest(data=data):
                 result = self.run_pcm(data)
                 self.assertEqual(result.returncode, 2)