{"id":"image-jxss","mimeType":"image/jxss","name":"JPEG XS Image Sequence (HEIF Container)","shortName":"JPEG-XS-Sequence","category":"Professional \u0026 Video Production","extensions":[".jxss",".jxs"],"description":"The image/jxss MIME type represents a sequence or animation of JPEG XS (Extra Speed) images encapsulated within a High Efficiency Image File Format (HEIF) container. It merges the ultra-low latency and low-complexity wavelet compression of JPEG XS with the powerful timing, track, and metadata capabilities of the ISOBMFF standard, making it ideal for storing broadcast video snippets or HDR burst captures.","seo":{"title":"image/jxss MIME Type | Complete Developer Reference \u0026 Magic Bytes","description":"Complete reference for the image/jxss MIME type: magic bytes, software support, HTTP headers, developer snippets, and technical specifications for HEIF-encapsulated JPEG XS image sequences.","faqs":[{"question":"What is the difference between image/jxsi and image/jxss?","answer":"Both use the HEIF (ISOBMFF) container to store JPEG XS compressed data. However, image/jxsi is intended for a single still image or a static collection of images, while image/jxss is specifically designed to store an image sequence (such as a video snippet, animation, or burst capture) that is meant to be played back chronologically."},{"question":"What is the magic byte for an image/jxss file?","answer":"As an ISOBMFF/HEIF container, an image/jxss file begins with a 4-byte box size, followed by the 'ftyp' box identifier, and the major brand 'jxss'. The hex representation of this signature is XX XX XX XX 66 74 79 70 6A 78 73 73."},{"question":"Can I view image/jxss animations in a web browser?","answer":"No. Modern web browsers do not support JPEG XS compression or HEIF containers natively. For web-based animations or video sequences, standard formats like Animated WebP, AVIF, or MP4 video must be used."}]},"index":{"compression":["Lossy (Visually Lossless)","Mathematically Lossless"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Live Broadcast Video Snippets","Medical Imaging Sequences","HDR Burst Photography Archiving","Automotive \u0026 Drone Video Storage"]},"technical":{"magicBytes":{"hex":"XX XX XX XX 66 74 79 70 6A 78 73 73","ascii":"....ftypjxss"},"container":"HEIF / ISOBMFF (ISO/IEC 23008-12)","compressionAlgorithm":["JPEG XS (ISO/IEC 21122-1)"],"colorDepth":["8-bit","10-bit","12-bit","14-bit","16-bit"],"transparency":true,"animation":true,"metadata":{"exif":true,"xmp":true,"iccProfile":true},"alphaChannel":true,"progressiveLoading":false,"hdrSupport":true},"history":{"developer":"Joint Photographic Experts Group (JPEG)","released":"2019","specification":"ISO/IEC 21122-3 (JPEG XS Part 3) / HEIF"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"intoPIX FastTICO-XS","logo":""},{"name":"FFmpeg (with external libraries)","logo":""}],"conversion":{"convertTo":["mxf","gif","webp"],"convertFrom":["mxf","sdi_video"]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/jxss"}],"htmlAccept":"image/jxss, .jxss","fileDetection":["Check bytes 4-7 for the ISOBMFF 'ftyp' box identifier","Verify the major brand string at bytes 8-11 is exactly 'jxss' (6A 78 73 73)"]},"prosCons":{"pros":["Provides sub-millisecond encoding and decoding latency across a video sequence while retaining visually lossless quality","Leverages the robust ISOBMFF track structures for accurate frame timing, audio synchronization, and metadata handling","Optimized for professional video production and IP broadcasting workflows"],"cons":["Zero web browser compatibility, limiting its use entirely to professional and industrial hardware workflows","Compression ratios are significantly lower than consumer video codecs like HEVC or AV1","Extremely niche format that requires highly specialized broadcast hardware or custom software libraries to process"]},"specifications":{"url":"https://jpeg.org/jpegxs/","rfc":"","mimeAliases":["image/heif-sequence"]},"developerSnippets":{"python":"import magic\nprint(magic.from_file('sequence.jxss', mime=True)) # May default to generic 'image/heif' or 'application/octet-stream'","nodejs":"const FileType = require('file-type');\nconst type = await FileType.fromFile('sequence.jxss');\nconsole.log(type?.mime); // Standard libraries will likely fail to identify the specific 'jxss' HEIF brand","go":"import \"net/http\"\n// Custom ISOBMFF box parsing is required to extract the 'jxss' brand from the ftyp box.","php":"$mime = mime_content_type('sequence.jxss');\necho $mime; // Standard server configurations often map this to application/octet-stream"},"relatedFormats":[]}