{"action":"created","issue":{"url":"https://api.github.com/repos/google/shaka-player/issues/1098","repository_url":"https://api.github.com/repos/google/shaka-player","labels_url":"https://api.github.com/repos/google/shaka-player/issues/1098/labels{/name}","comments_url":"https://api.github.com/repos/google/shaka-player/issues/1098/comments","events_url":"https://api.github.com/repos/google/shaka-player/issues/1098/events","html_url":"https://github.com/google/shaka-player/issues/1098","id":269939347,"number":1098,"title":"Problem with presentationTimeOffset","user":{"login":"tjber","id":33248264,"avatar_url":"https://avatars1.githubusercontent.com/u/33248264?v=4","gravatar_id":"","url":"https://api.github.com/users/tjber","html_url":"https://github.com/tjber","followers_url":"https://api.github.com/users/tjber/followers","following_url":"https://api.github.com/users/tjber/following{/other_user}","gists_url":"https://api.github.com/users/tjber/gists{/gist_id}","starred_url":"https://api.github.com/users/tjber/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tjber/subscriptions","organizations_url":"https://api.github.com/users/tjber/orgs","repos_url":"https://api.github.com/users/tjber/repos","events_url":"https://api.github.com/users/tjber/events{/privacy}","received_events_url":"https://api.github.com/users/tjber/received_events","type":"User","site_admin":false},"labels":[{"id":159144977,"url":"https://api.github.com/repos/google/shaka-player/labels/duplicate","name":"duplicate","color":"cccccc","default":true}],"state":"closed","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":5,"created_at":"2017-10-31T12:25:20Z","updated_at":"2017-11-06T13:38:40Z","closed_at":"2017-10-31T18:26:51Z","author_association":"NONE","body":"Hi,\r\n\r\nContinued with [https://groups.google.com/forum/#!topic/shaka-player-users/2RK662rDMk8]\r\n\r\nI didn't try to play it with the master. \r\nI have used the demo application of version 2.2.4 in chrome and firefox\r\n\r\nI have a system in which I will receive a series of video files containing a number of black frames at the beginning. \r\nCurrently the process to play those files is to transcode them to remove those frames and start playing from 0, but I'd like to skip this step.\r\nSo, I tried to use the presentationTimeOffset attribute in the mpd file.\r\n`<SegmentBase indexRangeExact=\"true\" indexRange=\"\"  presentationTimeOffset=\"\" >`\r\n\r\nThe problem is that I need frame accuracy and it seems that this attribute only has second precision.\r\nI have tried several combinations with this attribute and the timeScale without success. Dash especifications says :\r\n\r\n> presentationTimeOffset : The value of the presentation time offset in seconds is the division of the value of this attribute and the value of the timescale attribute.\r\n\r\nbut I get the feeling that this attribute is not being taken into account.\r\n\r\nI attach the mpd file I'm testing with. \r\n[dash.mpd.txt](https://github.com/google/shaka-player/files/1430622/dash.mpd.txt)\r\n\r\nI have updated in dropbox the files with which the issue can be played back, and I have added a file in which you can see the expected result (expected_file.mp4)   https://www.dropbox.com/sh/zfbynu6n9bxhd9q/AAB4TEvA9g71UADgne0pqwKia?dl=0 \r\n\r\nWhat I would like to do is to skip the initial frames (marked with a white counter) and that the playback starts in frame marked with the TC 00:00:00:00 of the file with the green TC, after that, in the second period skip the initial frames again and that the playback starts in frame marked with the TC 00:00:00:00 of the file with the red TC.\r\n\r\nCurrently if I try to jump 3.12 seconds actually a jump of 4 seconds is made, so for the first period the playback starts at TC 00:00:00:22 instead of 00:00:00:00 and the second period does not jump at all. \r\n\r\nIf I can change some of the manifest file to make this work, any ideas will be welcome.\r\n\r\nThank you in advance. \r\nTJ\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/google/shaka-player/issues/comments/342150872","html_url":"https://github.com/google/shaka-player/issues/1098#issuecomment-342150872","issue_url":"https://api.github.com/repos/google/shaka-player/issues/1098","id":342150872,"user":{"login":"tjber","id":33248264,"avatar_url":"https://avatars1.githubusercontent.com/u/33248264?v=4","gravatar_id":"","url":"https://api.github.com/users/tjber","html_url":"https://github.com/tjber","followers_url":"https://api.github.com/users/tjber/followers","following_url":"https://api.github.com/users/tjber/following{/other_user}","gists_url":"https://api.github.com/users/tjber/gists{/gist_id}","starred_url":"https://api.github.com/users/tjber/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tjber/subscriptions","organizations_url":"https://api.github.com/users/tjber/orgs","repos_url":"https://api.github.com/users/tjber/repos","events_url":"https://api.github.com/users/tjber/events{/privacy}","received_events_url":"https://api.github.com/users/tjber/received_events","type":"User","site_admin":false},"created_at":"2017-11-06T13:38:40Z","updated_at":"2017-11-06T13:38:40Z","author_association":"NONE","body":"Hi!\r\nI've tried again, both with the Demo app and the master.\r\n\r\nThe timescale attribute is already taken into account in the SegmentBase, but frame accuracy is not yet possible, it only jumps from second to second.\r\nI mean, with these values: \r\n\t`<SegmentBase indexRangeExact=\"true\" indexRange=\"915-1138\" timescale = \"100\"  presentationTimeOffset=\"212\" >`\r\nPlayback starts at second 3, not 2,120.\r\n\r\nAlso, If the manifest has more than 1 period, the presentationTimeOffset is only taken into account in the first period, playback of the following periods starts in the second 0.\r\n\r\nThis is the mpd file i used for testing.\r\n\r\n[dash.mpd.txt](https://github.com/google/shaka-player/files/1446136/dash.mpd.txt)\r\n\r\nThanks! \r\n"}}
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