{
  "schema": 1,
  "spec": "openstream",
  "specVersion": "NXS1",
  "generatedAt": "2026-09-13T09:48:49.844Z",
  "implementation": {
    "name": "nixamp",
    "version": "0.24.2"
  },
  "environment": {
    "runtime": "node v24.20.0",
    "zstd": "1.5.7",
    "zlib": "1.3.2.1-motley-42c2f19",
    "os": "linux 6.17.0-1022-azure",
    "arch": "x64",
    "cpu": "INTEL(R) XEON(R) PLATINUM 8573C",
    "cores": 4,
    "memoryGiB": 15.6
  },
  "envelope": {
    "magic": "NXS1",
    "streamHeaderBytes": 16,
    "frameHeaderBytes": 48
  },
  "policy": {
    "minSavingsPercent": 3,
    "minSavingsBytes": 512,
    "maxBlockBytes": 262144,
    "zstdLevels": [
      1,
      3,
      9
    ]
  },
  "samples": [
    {
      "sample": "random-1mib",
      "kind": "synthetic",
      "inputBytes": 1048576,
      "sha256": "562a223dca6ae12049e4e88ded6b6c0c7d18f29d5b941309fcd1f5cc19bc15b0",
      "container": "bytes",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 24.17,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 7.11,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 4.2,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 12.7,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 1,
          "inputBytes": 1048576,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 99.99,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": false,
          "note": "not a transport stream: ts-zstd does not apply"
        }
      ],
      "recommendation": {
        "mode": "stored",
        "level": 0,
        "reason": "no codec beat stored by the configured margin"
      }
    },
    {
      "sample": "zeros-1mib",
      "kind": "synthetic",
      "inputBytes": 1048576,
      "sha256": "30e14955ebf1352266dc2ff8067e68104607e750abb9d3b36582b8af909fcb58",
      "container": "bytes",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1156,
          "wireBytes": 1412,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.87,
          "encodeMs": 2.7,
          "decodeMs": 3.68,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 104,
          "wireBytes": 360,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.97,
          "encodeMs": 1.03,
          "decodeMs": 4.35,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 104,
          "wireBytes": 360,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.97,
          "encodeMs": 0.68,
          "decodeMs": 3.15,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 100,
          "wireBytes": 356,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.97,
          "encodeMs": 4.14,
          "decodeMs": 3.52,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 1,
          "inputBytes": 1048576,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 99.99,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": false,
          "note": "not a transport stream: ts-zstd does not apply"
        }
      ],
      "recommendation": {
        "mode": "zstd",
        "level": 9,
        "reason": "saves 99.97% of the complete wire size"
      }
    },
    {
      "sample": "text-repeat-1mib",
      "kind": "synthetic",
      "inputBytes": 1048576,
      "sha256": "d05bf128d112bfd591628a68880676f643191beeb91d1250ce8c98212bf6e464",
      "container": "bytes",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 1048576,
          "wireBytes": 1048832,
          "storedBlocks": 4,
          "compressedBlocks": 0,
          "savingsPercent": -0.02,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 3358,
          "wireBytes": 3614,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.66,
          "encodeMs": 2.55,
          "decodeMs": 3.34,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 312,
          "wireBytes": 568,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.95,
          "encodeMs": 0.54,
          "decodeMs": 3.07,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 312,
          "wireBytes": 568,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.95,
          "encodeMs": 0.71,
          "decodeMs": 3.15,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 4,
          "inputBytes": 1048576,
          "payloadBytes": 312,
          "wireBytes": 568,
          "storedBlocks": 0,
          "compressedBlocks": 4,
          "savingsPercent": 99.95,
          "encodeMs": 2.91,
          "decodeMs": 3.07,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 1,
          "inputBytes": 1048576,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 99.99,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": false,
          "note": "not a transport stream: ts-zstd does not apply"
        }
      ],
      "recommendation": {
        "mode": "zstd",
        "level": 1,
        "reason": "saves 99.95% of the complete wire size"
      }
    },
    {
      "sample": "ts-padded-50pct",
      "kind": "synthetic",
      "inputBytes": 752000,
      "sha256": "fbbe8a14abcd5d36e40ccf8d5d80eca805580cccd632842a4f1cea9461863a6d",
      "container": "mpegts",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 379429,
          "wireBytes": 379637,
          "storedBlocks": 0,
          "compressedBlocks": 3,
          "savingsPercent": 49.52,
          "encodeMs": 8.95,
          "decodeMs": 3.92,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 377818,
          "wireBytes": 378026,
          "storedBlocks": 0,
          "compressedBlocks": 3,
          "savingsPercent": 49.73,
          "encodeMs": 2.6,
          "decodeMs": 2.2,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 375926,
          "wireBytes": 376134,
          "storedBlocks": 0,
          "compressedBlocks": 3,
          "savingsPercent": 49.98,
          "encodeMs": 3.91,
          "decodeMs": 2.29,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 375853,
          "wireBytes": 376061,
          "storedBlocks": 0,
          "compressedBlocks": 3,
          "savingsPercent": 49.99,
          "encodeMs": 11.14,
          "decodeMs": 2.26,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 375472,
          "wireBytes": 375680,
          "storedBlocks": 0,
          "compressedBlocks": 3,
          "savingsPercent": 50.04,
          "encodeMs": 5.97,
          "decodeMs": 4.87,
          "roundTrip": true
        }
      ],
      "recommendation": {
        "mode": "ts-zstd",
        "level": 1,
        "reason": "saves 50.04% of the complete wire size"
      }
    },
    {
      "sample": "ts-unpadded",
      "kind": "synthetic",
      "inputBytes": 752000,
      "sha256": "675352f64a65d9ec2c3d7b69f11bb253cd882c3fcea85dd4a994675b5767c2c5",
      "container": "mpegts",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 18.55,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 3.16,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 3.17,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 22.3,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 3,
          "inputBytes": 752000,
          "payloadBytes": 752000,
          "wireBytes": 752208,
          "storedBlocks": 3,
          "compressedBlocks": 0,
          "savingsPercent": -0.03,
          "encodeMs": 3.3,
          "decodeMs": 0,
          "roundTrip": true
        }
      ],
      "recommendation": {
        "mode": "stored",
        "level": 0,
        "reason": "no codec beat stored by the configured margin"
      }
    },
    {
      "sample": "tiny-3b",
      "kind": "synthetic",
      "inputBytes": 3,
      "sha256": "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad",
      "container": "bytes",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 1,
          "inputBytes": 3,
          "payloadBytes": 3,
          "wireBytes": 115,
          "storedBlocks": 1,
          "compressedBlocks": 0,
          "savingsPercent": -3733.33,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 1,
          "inputBytes": 3,
          "payloadBytes": 3,
          "wireBytes": 115,
          "storedBlocks": 1,
          "compressedBlocks": 0,
          "savingsPercent": -3733.33,
          "encodeMs": 0.17,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 1,
          "inputBytes": 3,
          "payloadBytes": 3,
          "wireBytes": 115,
          "storedBlocks": 1,
          "compressedBlocks": 0,
          "savingsPercent": -3733.33,
          "encodeMs": 0.11,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 1,
          "inputBytes": 3,
          "payloadBytes": 3,
          "wireBytes": 115,
          "storedBlocks": 1,
          "compressedBlocks": 0,
          "savingsPercent": -3733.33,
          "encodeMs": 0.13,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 1,
          "inputBytes": 3,
          "payloadBytes": 3,
          "wireBytes": 115,
          "storedBlocks": 1,
          "compressedBlocks": 0,
          "savingsPercent": -3733.33,
          "encodeMs": 0.6,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 1,
          "inputBytes": 3,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": -2033.33,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": false,
          "note": "not a transport stream: ts-zstd does not apply"
        }
      ],
      "recommendation": {
        "mode": "stored",
        "level": 0,
        "reason": "no codec beat stored by the configured margin"
      }
    },
    {
      "sample": "empty",
      "kind": "synthetic",
      "inputBytes": 0,
      "sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
      "container": "bytes",
      "rows": [
        {
          "mode": "stored",
          "level": 0,
          "blocks": 0,
          "inputBytes": 0,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 0,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "gzip",
          "level": 6,
          "blocks": 0,
          "inputBytes": 0,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 0,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 1,
          "blocks": 0,
          "inputBytes": 0,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 0,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 3,
          "blocks": 0,
          "inputBytes": 0,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 0,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "zstd",
          "level": 9,
          "blocks": 0,
          "inputBytes": 0,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 0,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        },
        {
          "mode": "ts-zstd",
          "level": 1,
          "blocks": 0,
          "inputBytes": 0,
          "payloadBytes": 0,
          "wireBytes": 64,
          "storedBlocks": 0,
          "compressedBlocks": 0,
          "savingsPercent": 0,
          "encodeMs": 0,
          "decodeMs": 0,
          "roundTrip": true
        }
      ],
      "recommendation": {
        "mode": "stored",
        "level": 0,
        "reason": "no codec beat stored by the configured margin"
      }
    }
  ],
  "summary": {
    "corpusBytes": 4649731,
    "byMode": [
      {
        "mode": "stored",
        "level": 0,
        "wireBytes": 4651091,
        "savingsPercent": -0.03,
        "roundTrip": true,
        "encodeMs": 0,
        "decodeMs": 0
      },
      {
        "mode": "gzip",
        "level": 6,
        "wireBytes": 2185882,
        "savingsPercent": 52.99,
        "roundTrip": true,
        "encodeMs": 57.09,
        "decodeMs": 10.94
      },
      {
        "mode": "zstd",
        "level": 1,
        "wireBytes": 2180173,
        "savingsPercent": 53.11,
        "roundTrip": true,
        "encodeMs": 14.55,
        "decodeMs": 9.62
      },
      {
        "mode": "zstd",
        "level": 3,
        "wireBytes": 2178281,
        "savingsPercent": 53.15,
        "roundTrip": true,
        "encodeMs": 12.8,
        "decodeMs": 8.59
      },
      {
        "mode": "zstd",
        "level": 9,
        "wireBytes": 2178204,
        "savingsPercent": 53.15,
        "roundTrip": true,
        "encodeMs": 53.79,
        "decodeMs": 8.85
      },
      {
        "mode": "ts-zstd",
        "level": 1,
        "wireBytes": 1127952,
        "savingsPercent": 25,
        "roundTrip": true,
        "encodeMs": 9.27,
        "decodeMs": 4.87
      }
    ]
  },
  "caveats": [
    "Envelope v1: a 16-byte stream header, a 48-byte header per frame, plus one end frame.",
    "OpenStream is a framing envelope over Zstandard and gzip, not a new compression algorithm; these numbers are those codecs at the block boundary, honestly framed.",
    "Synthetic samples do not predict production savings. A padded transport stream flatters a codec by its padding; an efficient real feed saves far less. Use --corpus with authorized real samples for numbers that mean something.",
    "Timings are wall-clock on the machine and runtime named in `environment` and do not transfer to other hardware.",
    "roundTrip:false in any row is a failure of exactness and must block a release."
  ]
}