OpenECS — Open EEG Codec Standard

Vendor-neutral benchmark standard for EEG signal compression. Grades any codec in any language against a hash-pinned corpus and produces a single reproducible compliance verdict.

• Crate: open-eeg-codec-standard · library: open_eeg_codec_standard · CLI: openecs
• Spec: SPEC/OpenECS-v1.0.md (normative) · STANDARD.md (narrative) · JSON schemas in SPEC/schemas/

Tiers

Grade	Tier	Global gate	Per-band (δθαβγ)
ECS-L	Lossless	integer-domain PRD = 0 exactly, CR ≥ 0.8	—
ECS-N	Near-Lossless	R ≥ 0.99, PRD ≤ 5 %, CR ≥ 1.0	—
ECS-C	Clinical	R ≥ 0.95, PRD ≤ 9 %, CR ≥ 20	required
ECS-M	Monitoring	R ≥ 0.85, PRD ≤ 20 %, CR ≥ 100	required
ECS-A	Alerting	R ≥ 0.70, PRD ≤ 40 %, CR ≥ 200	required
—	below floor	fails ECS-A	—

Grade is the highest tier fully satisfied. The lossless claim (ECS-L) is verified by integer-domain bit comparison — not inferred from the codec's own declaration.

Install

cargo install open-eeg-codec-standard   # openecs CLI
cargo add open-eeg-codec-standard       # library dependency

Quickstart

# Grade gzip + built-in baselines against the in-repo synthetic corpus
openecs bench --codec gzip --corpus-manifest corpora/ecs-smoke.toml \
    --charts --report report.html

Produces a ranked leaderboard (grade, pooled CR, mean-R 95 % bootstrap CI, paired sign-test p-value vs strongest baseline), terminal ASCII charts, and a self-contained HTML report with inline SVG.

Other subcommands: grade (single codec, single signal), verify-corpus (SHA-256 + shape check), emit-corpus-manifest (hash a directory of EDFs into a pinned manifest).

Codec contract (any language)

Two executables satisfying the file-based contract qualify:

<cmd> [prefix…] encode <in.edf>  <out.blob>
<cmd> [prefix…] decode <in.blob> <out.raw> --channels N --samples M --rate FS --dtype DT

Declare the invocation in a codec-manifest.toml (schema):

spec_version = "1.0"
[codec]
name            = "my-codec"
cmd             = "python3"
prefix_args     = ["my_codec.py"]
declared_lossless = false       # verified against actual output, not trusted
sample_dtype    = "i32"         # decode output width: i16 | i32 | i64
input_format    = "edf"         # edf (default) | ecs0
output_format   = "raw"         # raw (default) | ecs0

openecs bench --codec-manifest codec-manifest.toml \
    --corpus-manifest corpora/ecs-smoke.toml --report report.html

Library

use open_eeg_codec_standard::{adapter::Gzip, harness};

// signal: one Vec<i64> per channel (integer ADC counts)
let report = harness::run(&Gzip, &signal, 256.0);
println!("ECS-{}  CR {:.2}  R {:.4}", report.grade, report.cr, report.r);

Implement the Codec trait for an in-process codec, or use manifest + corpus::grade_manifest_parallel to drive an external subprocess against a full corpus.

Canonical corpus

For citable results use bench/ECS-Bench-v1/ (CHB-MIT subset, 4 recordings, 23 ch, 256 Hz, SHA-256 pinned):

cd bench/ECS-Bench-v1 && sh fetch.sh
openecs verify-corpus --corpus-manifest ECS-Bench-v1.toml
openecs bench --codec-manifest <yours> --corpus-manifest ECS-Bench-v1.toml --report r.html

License

Apache-2.0 — see LICENSE.