Delta Signal

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Audio steganography & watermarking. Encode/decode hidden messages that survive YouTube re-encoding.

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decode_audio Read-only

Decode every Delta Signal layer from a WAV or MP3 file at an https URL: heartbeat cipher, spectral glyph, prime count, watermark (needs the seed used to render), ggwave, modem text and SSTV pictures (returned as PNG).

urlstring, required

https URL of a WAV or MP3 file (convert other formats first)

seedstring

layersarray

Tools (5)

decode_audio

read-only

Argument	Type	Description
url*	string	https URL of a WAV or MP3 file (convert other formats first)
seed	string
layers	array

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "url"
  ],
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "description": "https URL of a WAV or MP3 file (convert other formats first)"
    },
    "seed": {
      "type": "string",
      "maxLength": 64
    },
    "layers": {
      "type": "array",
      "items": {
        "enum": [
          "heartbeat",
          "primes",
          "glyph",
          "watermark",
          "ggwave",
          "sstv",
          "modem"
        ],
        "type": "string"
      }
    }
  }
}

describe_engine

Free. Describe Delta Signal: layers, stings, defaults, limits and prices.

read-only

No arguments.

Input schema (JSON)

{
  "type": "object",
  "properties": {}
}

preview_card

Free. Render the SSTV signature card image for a message (PNG) so you can see what the picture sting will carry.

read-only

Argument	Type	Description
text*	string	Up to 38 characters

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "text"
  ],
  "properties": {
    "text": {
      "type": "string",
      "maxLength": 38,
      "description": "Up to 38 characters"
    }
  }
}

render_signature

Render a Delta Signal audio signature (WAV, 48 kHz) that hides your message: in the heartbeat rhythm, as text in the spectrogram, as an inaudible watermark, and optionally as an SSTV picture, a ggwave data chirp or modem tones. Returns a download link (kept 7 days) and a manifest. Survives YouTube-grade AAC/Opus.

Argument	Type	Description
seed	string	Watermark key; keep it to verify later
layers	object	Per-layer options: bed, heartbeat, primes, glyph {band: mid\|hi}, watermark {payload}
stings	array
message*	string	Printable ASCII, up to 32 characters
duration	number	Seconds of signature body (default 60)

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "message"
  ],
  "properties": {
    "seed": {
      "type": "string",
      "maxLength": 64,
      "description": "Watermark key; keep it to verify later"
    },
    "layers": {
      "type": "object",
      "description": "Per-layer options: bed, heartbeat, primes, glyph {band: mid|hi}, watermark {payload}",
      "propertyNames": {
        "type": "string"
      },
      "additionalProperties": {}
    },
    "stings": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "type"
        ],
        "properties": {
          "at": {
            "anyOf": [
              {
                "enum": [
                  "start",
                  "end"
                ],
                "type": "string"
              },
              {
                "type": "number",
                "minimum": 0
              }
            ]
          },
          "mode": {
            "type": "string",
            "description": "sstv: robot36|robot72|martin1; modem: 1200|300|rtty"
          },
          "text": {
            "type": "string",
            "maxLength": 140
          },
          "type": {
            "enum": [
              "sstv",
              "ggwave",
              "modem"
            ],
            "type": "string"
          },
          "protocol": {
            "type": "string",
            "description": "ggwave: audible-normal|audible-fast|audible-fastest|ultrasound-*|dt-*"
          }
        },
        "additionalProperties": {}
      },
      "maxItems": 8
    },
    "message": {
      "type": "string",
      "maxLength": 32,
      "description": "Printable ASCII, up to 32 characters"
    },
    "duration": {
      "type": "number",
      "maximum": 600,
      "minimum": 3,
      "description": "Seconds of signature body (default 60)"
    }
  }
}

verify_signature

Verify a Delta Signal audio signature at an https WAV URL: returns which hidden layers are present (found_layers) and whether the audio matches an expected message (matches: true/false, or null if no expected_message given). Cheaper than full decode — use it when you only need to confirm presence or identity.

read-only

Argument	Type	Description
url*	string	https URL of a WAV file
seed	string	Watermark key used when the signature was rendered
expected_message	string	Message you expect to find; omit to discover what is present

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "url"
  ],
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "description": "https URL of a WAV file"
    },
    "seed": {
      "type": "string",
      "maxLength": 64,
      "description": "Watermark key used when the signature was rendered"
    },
    "expected_message": {
      "type": "string",
      "maxLength": 32,
      "description": "Message you expect to find; omit to discover what is present"
    }
  }
}