# Video & Timecode Calc – SMPTE Timecode Arithmetic

> Video & Timecode Calc – SMPTE Timecode Arithmetic is a paid API for AI agents from video-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Add or subtract two SMPTE timecodes at a given frame rate (drop-frame aware), returning the result as a timecode, frame count, and real seconds.

## Facts

- Endpoint: GET https://video-calc.x402tookit.com/timecode-math?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/video-timecode-calc-smpte-timecode-arithmetic-15b72d90
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3Bji4nvC87PFb4K8BkWLp

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability video-timecode-calc-smpte-timecode-arithmetic-15b72d90
```

Example prompt: Add the SMPTE timecodes 01:02:30;15 and 00:45:10;20 at 29.97 drop-frame fps and tell me the result timecode, total frames, and real seconds.

## When to prefer this

Use this endpoint when you need precise SMPTE timecode addition or subtraction that is drop-frame aware — especially for broadcast (29.97 DF) or film (23.976, 24) workflows. Prefer it over manual frame counting because it handles the drop-frame discontinuity correctly and returns results in both frames and real seconds simultaneously. It is the right choice when your input is already in HH:MM:SS:FF timecode notation rather than raw frame counts (use the frame-count converter sibling for that).

## Known failure modes

- Invalid timecode format (not HH:MM:SS:FF or HH:MM:SS;FF) returns an error
- Unsupported fps value outside allowed set (23.976, 24, 25, 29.97, 30, 48, 50, 59.94, 60) returns an error
- Drop-frame requested for a non-drop-frame-compatible fps (only 29.97 and 59.94) returns an error
- Missing required parameters a or b returns a validation error
- Subtraction resulting in a negative timecode may return an error or zero-clamped result

## How this service works

Add or subtract two SMPTE timecodes at a given frame rate, drop-frame aware, with the result in frames and seconds.

## Output

Returns the arithmetic result as a SMPTE timecode string, the individual frame counts for each input, the result in total frames, real elapsed seconds, the fps used, and whether drop-frame was applied. May also include a summary, degraded flag, and disclaimer fields.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "a",
      "b"
     ],
     "properties": {
      "a": {
       "type": "string",
       "description": "First timecode, HH:MM:SS:FF (or ; before frames for drop-frame)"
      },
      "b": {
       "type": "string",
       "description": "Second timecode"
      },
      "op": {
       "type": "string",
       "description": "add (default) or subtract"
      },
      "fps": {
       "type": "string",
       "description": "23.976, 24, 25, 29.97, 30, 48, 50, 59.94 or 60 (default 24)"
      },
      "dropFrame": {
       "type": "string",
       "description": "true for drop-frame (29.97 and 59.94 only)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "fps": {
       "type": [
        "null",
        "string"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "result": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "aFrames": {
       "type": [
        "null",
        "number"
       ]
      },
      "bFrames": {
       "type": [
        "null",
        "number"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "dropFrame": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items":
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/video-timecode-calc-smpte-timecode-arithmetic-15b72d90/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from video-calc.x402tookit.com](https://www.zero.xyz/host/video-calc.x402tookit.com/llms.txt)