{"action":"opened","issue":{"url":"https://api.github.com/repos/mbunkus/mkvtoolnix/issues/1646","repository_url":"https://api.github.com/repos/mbunkus/mkvtoolnix","labels_url":"https://api.github.com/repos/mbunkus/mkvtoolnix/issues/1646/labels{/name}","comments_url":"https://api.github.com/repos/mbunkus/mkvtoolnix/issues/1646/comments","events_url":"https://api.github.com/repos/mbunkus/mkvtoolnix/issues/1646/events","html_url":"https://github.com/mbunkus/mkvtoolnix/issues/1646","id":145240667,"number":1646,"title":"File mysteriously smaller than expected","user":{"login":"Patneu","id":6571873,"avatar_url":"https://avatars.githubusercontent.com/u/6571873?v=3","gravatar_id":"","url":"https://api.github.com/users/Patneu","html_url":"https://github.com/Patneu","followers_url":"https://api.github.com/users/Patneu/followers","following_url":"https://api.github.com/users/Patneu/following{/other_user}","gists_url":"https://api.github.com/users/Patneu/gists{/gist_id}","starred_url":"https://api.github.com/users/Patneu/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Patneu/subscriptions","organizations_url":"https://api.github.com/users/Patneu/orgs","repos_url":"https://api.github.com/users/Patneu/repos","events_url":"https://api.github.com/users/Patneu/events{/privacy}","received_events_url":"https://api.github.com/users/Patneu/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-04-01T17:45:24Z","updated_at":"2016-04-01T17:45:24Z","closed_at":null,"body":"Hi,\r\n\r\nI edited an .mkv file with the MKVToolnix gui/mkvmerge version 9.0.1 for Ubuntu. The file had 1 video, 1 audio and 1 subtitle track and I selected the subtitle track to not be muxed. Now the resulting file's size somehow is only approximately half of the size of the original file. Since I didn't expect (and didn't see before) a single subtitle track to have this much weight when it comes to the overall file size and I understood that MKVToolnix doesn't change the other tracks (at least when not told to do so) by muxing/demuxing the file and I haven't seen this behaviour with over files edited the same day in the same way using the same version of the application I found that rather odd.\r\n\r\nAt first glance, except for the file size, the resulting file doesn't seem to have anything unusual to it. The video track seems intact as far as I can tell and has no (visible) decrease in quality. A second try didn't change the result.\r\n\r\nI don't think I'm allowed to upload the files for you since I don't own their copyright, however I attached a MediaInfo export for both. If I can provide any further info on this subject, I will.\r\n\r\nThanks for any hints on what's going on. ;-)\r\n\r\n[Input.txt](https://github.com/mbunkus/mkvtoolnix/files/200074/Input.txt)\r\n[Output.txt](https://github.com/mbunkus/mkvtoolnix/files/200078/Output.txt)\r\n"}}