{"id":23105617,"url":"https://github.com/alessiomaffeis/xmpng","last_synced_at":"2025-07-26T20:35:50.900Z","repository":{"id":33841517,"uuid":"37543606","full_name":"alessiomaffeis/XMPNG","owner":"alessiomaffeis","description":"XMPNG (Differential Motion PNG) is a simple lossless video codec, particularly well-suited for high quality screencasts and screen sharing applications","archived":false,"fork":false,"pushed_at":"2017-02-21T21:14:38.000Z","size":4,"stargazers_count":3,"open_issues_count":0,"forks_count":0,"subscribers_count":0,"default_branch":"master","last_synced_at":"2025-04-03T22:24:39.906Z","etag":null,"topics":["codec","lossless","video","video-codec"],"latest_commit_sha":null,"homepage":"","language":"C#","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/alessiomaffeis.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2015-06-16T16:55:22.000Z","updated_at":"2023-09-03T02:45:50.000Z","dependencies_parsed_at":"2022-08-17T23:00:41.040Z","dependency_job_id":null,"html_url":"https://github.com/alessiomaffeis/XMPNG","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/alessiomaffeis/XMPNG","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/alessiomaffeis%2FXMPNG","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/alessiomaffeis%2FXMPNG/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/alessiomaffeis%2FXMPNG/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/alessiomaffeis%2FXMPNG/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/alessiomaffeis","download_url":"https://codeload.github.com/alessiomaffeis/XMPNG/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/alessiomaffeis%2FXMPNG/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":267228949,"owners_count":24056373,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-07-26T02:00:08.937Z","response_time":62,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["codec","lossless","video","video-codec"],"created_at":"2024-12-17T00:52:44.147Z","updated_at":"2025-07-26T20:35:50.878Z","avatar_url":"https://github.com/alessiomaffeis.png","language":"C#","funding_links":[],"categories":[],"sub_categories":[],"readme":"# XMPNG\n\nXMPNG (Differential Motion PNG) is a simple lossless video codec, particularly well-suited for high quality screencasts and screen sharing applications. This is a quick, proof of concept C#/.NET implementation from an old academic project.\n\nThe concept is pretty straightforward: the encoder writes the initial **I** frame as a full PNG image, then it writes each subsequent **P** frame as the PNG encoded XOR \"difference\" with respect of its preceding frame (i.e. P2 = Frame 2 XOR Frame 1).\n\nThis method allows to greatly reduce both the inter-frame temporal redundancy, by means of the fast and effective XOR \"difference\", and the intra-frame spatial redundancy, thanks to PNG's own 2D prediction filter.\n\n![alt tag](http://i.imgur.com/SaEqSrQ.png)\n\n\nThen, the decoder can reconstruct the exact, original frames by making a XOR operation between each **P** frame and the previous reconstructed frame (e.g. Frame 2 = P2 XOR Frame 1)\n\n![alt tag](http://i.imgur.com/4eBBzYL.png)\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Falessiomaffeis%2Fxmpng","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Falessiomaffeis%2Fxmpng","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Falessiomaffeis%2Fxmpng/lists"}