{"success":true,"data":{"ext":"asf","name":"Microsoft Windows Media Audio/Video File","description":"Microsoft Windows Media Audio/Video File, based on the Advanced Systems Format, is a multimedia container format developed by Microsoft for the Windows Media family. It is used to store audio, video, and synchronized metadata for streaming, playback, and archival distribution in Windows Media Player and compatible software. As a legacy format, it is less common today, and files from untrusted sources should still be handled with standard caution.","mime":["video/x-ms-asf"],"risk_level":"Safe","signatures":[{"hex":"30 26 B2 75","offset":0,"sources":[{"name":"Apache Tika","url":"https://raw.githubusercontent.com/apache/tika/main/tika-core/src/main/resources/org/apache/tika/mime/tika-mimetypes.xml"}]},{"hex":"30 26 B2 75 8E 66 CF 11","offset":0,"sources":[{"name":"Wikipedia","url":"https://en.wikipedia.org/wiki/List_of_file_signatures"}]},{"hex":"A6 D9 00 AA 00 62 CE 6C","offset":0,"sources":[{"name":"Wikipedia","url":"https://en.wikipedia.org/wiki/List_of_file_signatures"}]},{"hex":"30 26 B2 75 8E 66 CF 11 A6 D9 00 AA 00 62 CE 6C","offset":0,"sources":[{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]}],"related":["wmv","avi","mp4","3g2","3gp","flv"],"usage":{"python":"def is_asf(file_path: str) -> bool:\n    \"\"\"Check if file is a valid ASF by magic bytes.\"\"\"\n    signature = bytes([0x30, 0x26, 0xB2, 0x75])\n    with open(file_path, \"rb\") as f:\n        return f.read(4) == signature","node":"function isASF(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x30, 0x26, 0xB2, 0x75]);\n  return buffer.subarray(0, 4).equals(signature);\n}","go":"func IsASF(data []byte) bool {\n    signature := []byte{0x30, 0x26, 0xB2, 0x75}\n    if len(data) < 4 {\n        return false\n    }\n    return bytes.Equal(data[:4], signature)\n}"},"category":"Video"}}