[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"extension:v3:en:h261":3},{"resolvedFromAlias":4,"canonicalExt":5,"ext":5,"name":6,"category":7,"categoryName":8,"updatedAt":9,"popularity":10,"summary":11,"howToOs":12,"quickAnswer":18,"answerIntro":19,"whatIs":20,"description":21,"furtherReading":22,"openInstructions":32,"commonIssues":44,"securityNotes":57,"faq":61,"aliases":68,"mimeTypes":69,"relatedExtensions":70,"breadcrumbs":114,"categoryAnchor":124,"categoryFuturePath":125,"metaDescription":126,"availableHowToOs":127,"openOnDeviceLinks":128,"cannotOpenReasons":144,"cannotOpenFixes":145,"fixIntentPath":146,"convertOptions":147,"convertIntentPath":151,"securityAffiliates":212},false,"h261","H.261 Video File","video","Video","2026-03-19T08:36:41.017Z",20,"H.261 is a video compression format primarily used for video conferencing and telephony.",[13,14,15,16,17],"windows","mac","linux","ios","android","To open .H261 files on Windows, install VLC Media Player.","H.261 files are video files that can be opened with media players that support this codec. To open an .h261 file, you need compatible video playback software.","H.261 is a video compression standard developed by the ITU-T for video conferencing applications. It was one of the first digital video compression formats and is designed for transmitting video over ISDN lines.","H.261 was developed in 1988 by the International Telecommunication Union (ITU) as a standard for video compression. It was primarily used in early video conferencing systems and was designed to work with ISDN lines, offering bit rates of p x 64 kbit/s, where p ranges from 1 to 30. This format laid the groundwork for subsequent video compression standards, such as H.263 and H.264, by introducing concepts like motion compensation and discrete cosine transform (DCT) based compression.\n\nAlthough H.261 is largely obsolete today, it played a critical role in the development of digital video technology. It was used in early video conferencing systems and some broadcast applications. The format is not commonly used for new projects, as more efficient codecs like H.264 have become the standard.\n\nH.261 files are typically found in archival footage or older systems that still rely on legacy technology. Modern media players might not support H.261 natively, requiring specific codecs or plugins to decode and play these files.",[23,26,29],{"title":24,"url":25},"H.261 on Wikipedia","https://en.wikipedia.org/wiki/H.261",{"title":27,"url":28},"VLC Media Player Official Site","https://www.videolan.org/vlc/",{"title":30,"url":31},"Understanding Video Codecs","https://www.lifewire.com/video-codecs-explained-1082167",{"windows":33,"macos":36,"linux":37,"ios":39,"android":41},[34,35],"Install VLC Media Player.","Open VLC and drag the .h261 file into the player.",[34,35],[38,35],"Install VLC Media Player via the package manager.",[40],"Use a media player app like VLC for Mobile that supports H.261.",[42,43],"Install VLC for Android from the Google Play Store.","Open VLC and select the .h261 file to play.",[45,51],{"title":46,"description":47,"steps":48},"File won't open","The file may not open due to a lack of codec support.",[49,50],"Ensure VLC Media Player is installed.","Check for any available codec packs and install them.",{"title":52,"description":53,"steps":54},"Choppy playback","Video playback might be choppy if the system is underpowered.",[55,56],"Close other applications to free up resources.","Ensure your media player is up to date.",[58,59,60],"Ensure the source of the .h261 file is trusted to avoid malware.","Keep your media player software updated to protect against vulnerabilities.","Be cautious of downloading codec packs from unverified sources.",[62,65],{"question":63,"answer":64},"Can I convert H.261 to a more common format?","Yes, you can use video conversion software like HandBrake or FFmpeg to convert H.261 files to formats like MP4.",{"question":66,"answer":67},"Why is my media player not recognizing the .h261 file?","Your media player may not support the H.261 codec. Try using VLC Media Player or install the necessary codecs.",[],[],[71,77,83,89,93,98,104,109],{"ext":72,"name":73,"category":7,"categoryName":8,"popularity":74,"summary":75,"howToOs":76},"mp4","MPEG-4 Part 14 Video",95,"MP4 is a popular multimedia container format used for storing video, audio, subtitles, and metadata, ideal for streaming and sharing across devices.",[13,14,15,16,17],{"ext":78,"name":79,"category":7,"categoryName":8,"popularity":80,"summary":81,"howToOs":82},"mkv","Matroska Video",70,"MKV is a versatile multimedia container format known for supporting high-quality video and multiple audio and subtitle tracks.",[13,14,15,16,17],{"ext":84,"name":85,"category":7,"categoryName":8,"popularity":86,"summary":87,"howToOs":88},"3gp","3rd Generation Partnership Project Multimedia File",65,"3GP is a multimedia container format primarily used for 3G mobile phones, but also playable on some 2G and 4G phones.",[13,14,15,16,17],{"ext":90,"name":85,"category":7,"categoryName":8,"popularity":86,"summary":91,"howToOs":92},"3gpp","3GPP files are multimedia files used primarily for video and audio streaming on mobile networks.",[13,14,15,16,17],{"ext":94,"name":95,"category":7,"categoryName":8,"popularity":86,"summary":96,"howToOs":97},"mts","MPEG Transport Stream","MTS files are video files saved in the Advanced Video Codec High Definition (AVCHD) format, commonly used by Sony and Panasonic camcorders.",[13,14,15,16,17],{"ext":99,"name":100,"category":7,"categoryName":8,"popularity":101,"summary":102,"howToOs":103},"av1","AOMedia Video 1",60,"AV1 is a modern, open-source video codec designed for high-quality video streaming.",[13,14,15,16,17],{"ext":105,"name":106,"category":7,"categoryName":8,"popularity":101,"summary":107,"howToOs":108},"m2ts","MPEG-2 Transport Stream","M2TS files are used for multiplexing audio, video, and other streams, often found in Blu-ray discs and AVCHD camcorders.",[13,14,15,16,17],{"ext":110,"name":111,"category":7,"categoryName":8,"popularity":101,"summary":112,"howToOs":113},"xvid","Xvid Video File","Xvid is a popular video codec used for compressing video files to save space while maintaining quality.",[13,14,15,16,17],[115,118,121],{"label":116,"to":117},"Home","/",{"label":119,"to":120},"File Extension Index","/file-extension",{"label":122,"to":123},".H261","/file-extension/h261","category-video","/category/video","Learn what .H261 files are, how to open them on every platform, common fixes, and security best practices.",[13,14,15,16,17],[129,132,135,138,141],{"os":13,"label":130,"to":131},"Open .H261 on Windows","/how-to/open-h261-on-windows",{"os":14,"label":133,"to":134},"Open .H261 on Mac","/how-to/open-h261-on-mac",{"os":15,"label":136,"to":137},"Open .H261 on Linux","/how-to/open-h261-on-linux",{"os":16,"label":139,"to":140},"Open .H261 on iOS","/how-to/open-h261-on-ios",{"os":17,"label":142,"to":143},"Open .H261 on Android","/how-to/open-h261-on-android",[46,52],[49,50],"/fix/h261",[148,152,155,159,163,167,170,174,177,181,184,188,192,196,200,204,208],{"fromExt":5,"toExt":149,"toLabel":150,"path":151},"3g2",".3G2","/how-to/convert/h261-to-3g2",{"fromExt":5,"toExt":84,"toLabel":153,"path":154},".3GP","/how-to/convert/h261-to-3gp",{"fromExt":5,"toExt":156,"toLabel":157,"path":158},"asf",".ASF","/how-to/convert/h261-to-asf",{"fromExt":5,"toExt":160,"toLabel":161,"path":162},"avi",".AVI","/how-to/convert/h261-to-avi",{"fromExt":5,"toExt":164,"toLabel":165,"path":166},"flv",".FLV","/how-to/convert/h261-to-flv",{"fromExt":5,"toExt":105,"toLabel":168,"path":169},".M2TS","/how-to/convert/h261-to-m2ts",{"fromExt":5,"toExt":171,"toLabel":172,"path":173},"m4v",".M4V","/how-to/convert/h261-to-m4v",{"fromExt":5,"toExt":78,"toLabel":175,"path":176},".MKV","/how-to/convert/h261-to-mkv",{"fromExt":5,"toExt":178,"toLabel":179,"path":180},"mov",".MOV","/how-to/convert/h261-to-mov",{"fromExt":5,"toExt":72,"toLabel":182,"path":183},".MP4","/how-to/convert/h261-to-mp4",{"fromExt":5,"toExt":185,"toLabel":186,"path":187},"mpg",".MPG","/how-to/convert/h261-to-mpg",{"fromExt":5,"toExt":189,"toLabel":190,"path":191},"mxf",".MXF","/how-to/convert/h261-to-mxf",{"fromExt":5,"toExt":193,"toLabel":194,"path":195},"ogv",".OGV","/how-to/convert/h261-to-ogv",{"fromExt":5,"toExt":197,"toLabel":198,"path":199},"swf",".SWF","/how-to/convert/h261-to-swf",{"fromExt":5,"toExt":201,"toLabel":202,"path":203},"vob",".VOB","/how-to/convert/h261-to-vob",{"fromExt":5,"toExt":205,"toLabel":206,"path":207},"webm",".WEBM","/how-to/convert/h261-to-webm",{"fromExt":5,"toExt":209,"toLabel":210,"path":211},"wmv",".WMV","/how-to/convert/h261-to-wmv",[213,217],{"name":214,"description":215,"affiliateUrl":216},"Avast","Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.","https://www.avast.com/lp-aff-consumer-store?expid=inf601",{"name":218,"description":219,"affiliateUrl":220},"Norton","Norton 360 delivers comprehensive antivirus protection, VPN, and identity theft monitoring. Scan files for threats before opening to keep your device secure.","http://buy.norton.com/aff_home?utm_campaign=en-ww_nor_n36_aff_nas_nau_nah_cj_nad_low:_sec_nat_mktc_norton_360"]