MCP FFmpeg Helper

Instructions

Implementation Reference

• src/tools/handlers.ts:39-54 (handler)

  Handler function for the 'extract_audio' tool. Validates inputs, constructs FFmpeg command to extract audio without video (-vn -acodec), runs it, and returns completion message.

  case "extract_audio": {
    const inputPath = validatePath(String(args?.inputPath), true);
    const outputPath = validatePath(String(args?.outputPath));
    const format = String(args?.format || "mp3");
    
    await ensureDirectoryExists(outputPath);
    const command = `-i "${inputPath}" -vn -acodec ${format} "${outputPath}" -y`;
    const result = await runFFmpegCommand(command);
    
    return {
      content: [{
        type: "text",
        text: `Audio extraction completed: ${inputPath} → ${outputPath}\n\n${result}`
      }]
    };
  }

• src/tools/definitions.ts:42-63 (schema)

  Input schema definition for the 'extract_audio' tool, specifying required parameters: inputPath, outputPath, and format.

  {
    name: "extract_audio",
    description: "Extract audio from a video file",
    inputSchema: {
      type: "object",
      properties: {
        inputPath: {
          type: "string",
          description: "Path to the input video file"
        },
        outputPath: {
          type: "string",
          description: "Path for the output audio file"
        },
        format: {
          type: "string",
          description: "Audio format (mp3, aac, etc.)"
        }
      },
      required: ["inputPath", "outputPath", "format"]
    }
  },

• src/index.ts:46-50 (registration)

  Registration of all tools, including 'extract_audio', by returning the toolDefinitions array in response to ListToolsRequest.

  server.setRequestHandler(ListToolsRequestSchema, async () => {
    return {
      tools: toolDefinitions
    };
  });