{"id":"image-avcs","mimeType":"image/avcs","name":"AVC Image Sequence (HEIF Container)","shortName":"AVCS","category":"Photography \u0026 Professional","extensions":[".avcs",".heifs"],"description":"AVCS (Advanced Video Coding Image Sequence) is a format that stores a sequence of images, such as burst photography or short animations, encoded with the AVC (H.264) codec within a High Efficiency Image File Format (HEIF) container.","seo":{"title":"image/avcs MIME Type | Complete Developer Reference \u0026 Magic Bytes","description":"Complete reference for the image/avcs MIME type: magic bytes, browser support matrix, HTTP headers, developer snippets, and technical specifications for AVC-encoded HEIF image sequences.","faqs":[{"question":"What is the difference between image/avci and image/avcs?","answer":"While both use the AVC (H.264) codec inside a HEIF container, image/avci is used for single still images, whereas image/avcs is used for an image sequence (such as an animation or a camera burst)."},{"question":"What is the magic byte for AVCS?","answer":"AVCS uses the standard ISOBMFF container structure. The signature begins with a 4-byte box size, followed by the 'ftyp' identifier, and then the 'avcs' brand. The hex representation is XX XX XX XX 66 74 79 70 61 76 63 73."},{"question":"Can I use AVCS for web animations instead of GIF or WebP?","answer":"No, AVCS is not supported natively by web browsers. For web animations, formats like Animated WebP, AVIF, APNG, or standard MP4 video are strongly recommended."}]},"index":{"compression":["Lossy","Lossless"],"browserSupport":{"score":1,"label":"None"},"commonUses":["Burst Photography","Short Animations","Camera Capture","Archival Storage"]},"technical":{"magicBytes":{"hex":"XX XX XX XX 66 74 79 70 61 76 63 73","ascii":"....ftypavcs"},"container":"HEIF / ISOBMFF (ISO/IEC 14496-12)","compressionAlgorithm":["AVC (Advanced Video Coding / H.264)"],"colorDepth":["8-bit","10-bit","12-bit"],"transparency":true,"animation":true,"metadata":{"exif":true,"xmp":true,"iccProfile":true},"alphaChannel":true,"progressiveLoading":false,"hdrSupport":true},"history":{"developer":"Moving Picture Experts Group (MPEG) / ISO/IEC JTC 1","released":"2015","specification":"ISO/IEC 23008-12 (MPEG-H Part 12)"},"browserSupport":{"chrome":false,"chromeVersion":"None","firefox":false,"firefoxVersion":"None","safari":false,"safariVersion":"None","edge":false,"edgeVersion":"None","internetExplorer":false},"softwareSupport":[{"name":"Apple Photos (macOS/iOS)","logo":""},{"name":"ImageMagick","logo":"image-magic.webp"},{"name":"Windows Photos (with HEIF Extension)","logo":""}],"conversion":{"convertTo":["gif","webp","hevc"],"convertFrom":["gif","webp","hevc"]},"developer":{"httpHeaders":[{"header":"Content-Type","value":"image/avcs"}],"htmlAccept":"image/avcs, .avcs, .heifs","fileDetection":["Check for ISOBMFF 'ftyp' box starting at byte offset 4","Verify 'avcs' brand string starting at byte offset 8"]},"prosCons":{"pros":["Efficiently stores bursts of images or animations utilizing inter-frame compression","Leverages the highly compatible and widely hardware-accelerated AVC (H.264) codec","Robust HEIF container supports extensive metadata, alpha channels, and depth maps"],"cons":["Zero native support in web browsers","Largely superseded in efficiency by newer sequence formats like HEICS (HEVC) or Animated AVIF (AV1)","Complicated container structure requires specialized parsing libraries"]},"specifications":{"url":"https://www.iso.org/standard/89035.html","rfc":"","mimeAliases":["image/heif-sequence"]},"developerSnippets":{"python":"import magic\nprint(magic.from_file('burst.avcs', mime=True)) # May output 'image/avcs' or 'image/heif-sequence'","nodejs":"const FileType = require('file-type');\nconst type = await FileType.fromFile('burst.avcs');\nconsole.log(type.mime); // image/avcs","go":"import \"net/http\"\n\nmimeType := http.DetectContentType(fileBytes)\n// Go standard library lacks HEIF sequence detection; ISOBMFF parsing is required","php":"$mime = mime_content_type('burst.avcs');\necho $mime; // Standard magic database may lack specific 'avcs' signatures"},"relatedFormats":["avci","heic","heif"]}