{"action":"created","issue":{"url":"https://api.github.com/repos/jmacd/xdelta/issues/203","labels_url":"https://api.github.com/repos/jmacd/xdelta/issues/203/labels{/name}","comments_url":"https://api.github.com/repos/jmacd/xdelta/issues/203/comments","events_url":"https://api.github.com/repos/jmacd/xdelta/issues/203/events","html_url":"https://github.com/jmacd/xdelta/issues/203","id":104944592,"number":203,"title":"Unusual Delta output file size (Unsual comparing to the similar 'SmartVersion''s delta output file size)","user":{"login":"HotDenim","id":14130510,"avatar_url":"https://avatars.githubusercontent.com/u/14130510?v=3","gravatar_id":"","url":"https://api.github.com/users/HotDenim","html_url":"https://github.com/HotDenim","followers_url":"https://api.github.com/users/HotDenim/followers","following_url":"https://api.github.com/users/HotDenim/following{/other_user}","gists_url":"https://api.github.com/users/HotDenim/gists{/gist_id}","starred_url":"https://api.github.com/users/HotDenim/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/HotDenim/subscriptions","organizations_url":"https://api.github.com/users/HotDenim/orgs","repos_url":"https://api.github.com/users/HotDenim/repos","events_url":"https://api.github.com/users/HotDenim/events{/privacy}","received_events_url":"https://api.github.com/users/HotDenim/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2015-09-04T18:36:10Z","updated_at":"2015-09-05T09:56:35Z","closed_at":null,"body":"Unusual Delta output file size. Using xdelta on the 'Visual Studio 2013' Retail editions .ISO images.\r\n\r\n   The .ISO files can be downloaded from here:\r\n   \r\n   Ultimate Edition (2.9 GB): http://go.microsoft.com/fwlink/?LinkId=320679\r\n   Test Professional Edition (175 MB): http://download.microsoft.com/download/4/0/6/406E397F-EDBE-4437-B64F-40DF7A92A26E/VS2013_RTM_TESTPRO_ENU.iso\r\n   --\r\n   Premium Edition (2.9 GB): http://go.microsoft.com/fwlink/?LinkId=320676\r\n   Professional Edition (2.9 GB): http://go.microsoft.com/fwlink/?LinkId=320673\r\n\r\nWhen creating a delta from Ultimate Edition to Test Professional Edition, the delta file size is 160 MB. I tried the same process with SmartVersion (www.smartversion.com) and it produces a delta file of size 12 MB (more realistic considering the differences within the .ISO file). The Test_Professional is a subset of Ultimate (Test_Professional .ISO is only 175 MB).\r\n\r\nCan you explain ?. Surely xDelta should be producing something in the regions of what SmartVersion correctly produces ?, yes?. \r\n\r\n(As Expected: creating a delta from 'Ultimate' to ,'Premium' or  'Professional' , creates small deltas of approx 600Kb)"},"comment":{"url":"https://api.github.com/repos/jmacd/xdelta/issues/comments/137938017","html_url":"https://github.com/jmacd/xdelta/issues/203#issuecomment-137938017","issue_url":"https://api.github.com/repos/jmacd/xdelta/issues/203","id":137938017,"user":{"login":"mgrinzPlayer","id":9157726,"avatar_url":"https://avatars.githubusercontent.com/u/9157726?v=3","gravatar_id":"","url":"https://api.github.com/users/mgrinzPlayer","html_url":"https://github.com/mgrinzPlayer","followers_url":"https://api.github.com/users/mgrinzPlayer/followers","following_url":"https://api.github.com/users/mgrinzPlayer/following{/other_user}","gists_url":"https://api.github.com/users/mgrinzPlayer/gists{/gist_id}","starred_url":"https://api.github.com/users/mgrinzPlayer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mgrinzPlayer/subscriptions","organizations_url":"https://api.github.com/users/mgrinzPlayer/orgs","repos_url":"https://api.github.com/users/mgrinzPlayer/repos","events_url":"https://api.github.com/users/mgrinzPlayer/events{/privacy}","received_events_url":"https://api.github.com/users/mgrinzPlayer/received_events","type":"User","site_admin":false},"created_at":"2015-09-05T09:56:35Z","updated_at":"2015-09-05T09:56:35Z","body":"One extra example what bigger -B switch could do if jmacd implement it.\r\n\r\nFor now, we have to simulate it (it is not a perfect simulation). We can use 7zip for this. Add to archive \"Ultimate\" with 7zip, method: store, volume size: 1GB\r\n\r\nYou will get three files\r\n*VS2013_RTM_ULT_ENU.7z.001* (1GB)\r\n*VS2013_RTM_ULT_ENU.7z.002* (1GB)\r\n*VS2013_RTM_ULT_ENU.7z.003* (753MB)\r\n\r\nThen this\r\n```batch\r\nxdelta3 -0 -I 0 -B 1000000000 -W 16777216 -fves VS2013_RTM_ULT_ENU.7z.001 VS2013_RTM_TESTPRO_ENU.iso intermediate1.xd3\r\nxdelta3 -0 -I 0 -B 1000000000 -W 16777216 -fves VS2013_RTM_ULT_ENU.7z.002 intermediate1.xd3 intermediate2.xd3\r\nxdelta3 -0 -I 0 -B 1000000000 -W 16777216 -fves VS2013_RTM_ULT_ENU.7z.003 intermediate2.xd3 final.xd3\r\n```\r\n\r\nintermediate1.xd3 will be 77.2MB\r\nintermediate2.xd3 will be 43.6MB\r\nfinal.xd3 will be 29.2MB\r\n\r\nNote, because this is not a perfect simulation, final.xd3 size is bigger than it could be with finished xdelta3 (with big -B support)\r\n\r\n\r\nThen, you can delete *intermediate1.xd3* and *intermediate2.xd3* files. You will only need *final.xd3* and those three parts.\r\n\r\nTo decode, do this:\r\n```batch\r\nxdelta3_64 -fvds VS2013_RTM_ULT_ENU.7z.003 final.xd3 intermediate2.xd3\r\nxdelta3_64 -fvds VS2013_RTM_ULT_ENU.7z.002 intermediate2.xd3 intermediate1.xd3\r\nxdelta3_64 -fvds VS2013_RTM_ULT_ENU.7z.001 intermediate1.xd3 otherVS2013_RTM_TESTPRO_ENU.iso\r\n```\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n"}}