{"action":"created","issue":{"url":"https://api.github.com/repos/mpv-player/mpv/issues/1597","labels_url":"https://api.github.com/repos/mpv-player/mpv/issues/1597/labels{/name}","comments_url":"https://api.github.com/repos/mpv-player/mpv/issues/1597/comments","events_url":"https://api.github.com/repos/mpv-player/mpv/issues/1597/events","html_url":"https://github.com/mpv-player/mpv/issues/1597","id":57951582,"number":1597,"title":"cache useless with laggy NFS mounts","user":{"login":"skeller","id":238011,"avatar_url":"https://avatars.githubusercontent.com/u/238011?v=3","gravatar_id":"","url":"https://api.github.com/users/skeller","html_url":"https://github.com/skeller","followers_url":"https://api.github.com/users/skeller/followers","following_url":"https://api.github.com/users/skeller/following{/other_user}","gists_url":"https://api.github.com/users/skeller/gists{/gist_id}","starred_url":"https://api.github.com/users/skeller/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/skeller/subscriptions","organizations_url":"https://api.github.com/users/skeller/orgs","repos_url":"https://api.github.com/users/skeller/repos","events_url":"https://api.github.com/users/skeller/events{/privacy}","received_events_url":"https://api.github.com/users/skeller/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":10,"created_at":"2015-02-17T17:07:50Z","updated_at":"2015-02-18T21:24:28Z","closed_at":"2015-02-18T21:24:28Z","body":"It took me quite a while to find the root cause. mpv's cache seems to be useless for its intended purpose. I have a media library mounted via NFS over a wireless link (at that point 802.11a, as Intel's drivers were unusable in n mode). Playing full-hd movies worked most of the time but sometimes resulted in intermittent stutters of about one second. mpv then often showed a frame drop of one frame, but the hang was much longer than 1/24 s.\r\nThe hangs were somehow related to NFS blocking for quite some time. When they happened the mpv console output would freeze for the duration of the hang. The cache was set to --cache-secs=60 and was fully populated (60s+12500KB) when the stutter occured.\r\nSystem is fast enough for video playback. Didn't matter whether audio was enabled or not (tried -ao null, changing audio track to disabled) or whether software decoding or VAAPI was used.\r\nMoving the mount to a cifs-based mount solved the issues mostly (the hangs weren't there anymore but a few frames were dropped occasionally) and even better with sshfs. Fully solved with re-enabling 802.11n and using CIFS now (n seems to be stable now). Even with 802.11n and NFS there are still problems, though much less often.\r\nI would expect the cache to be exactly for this case: Laggy / slow network source. Note that even with 802.11a the network is fast enough on average and the cache never gets empty while playing. It seems mpv cannot cope with the file operation blocking or taking a long time to complete. Ideally the demuxers etc. should still run and take the data from the cache while the cache-fill thread is waiting for new data.\r\nSystem is a up-to-date Arch Linux, 64 Bits, Intel HD4xxx graphics, 8 GB RAM.\r\nVLC works in the same situation, even with NFS mounted over the slower 802.11a wifi link.\r\n\r\nmpv --version:\r\n\r\nmpv 0.7.3 (C) 2000-2015 mpv/MPlayer/mplayer2 projects\r\n built on 2015-01-28T14:38:25\r\nffmpeg library versions:\r\n   libavutil       54.15.100\r\n   libavcodec      56.13.100\r\n   libavformat     56.15.102\r\n   libswscale      3.1.101\r\n   libavfilter     5.2.103\r\n   libswresample   1.1.100\r\n"},"comment":{"url":"https://api.github.com/repos/mpv-player/mpv/issues/comments/74950893","html_url":"https://github.com/mpv-player/mpv/issues/1597#issuecomment-74950893","issue_url":"https://api.github.com/repos/mpv-player/mpv/issues/1597","id":74950893,"user":{"login":"wm4","id":1387750,"avatar_url":"https://avatars.githubusercontent.com/u/1387750?v=3","gravatar_id":"","url":"https://api.github.com/users/wm4","html_url":"https://github.com/wm4","followers_url":"https://api.github.com/users/wm4/followers","following_url":"https://api.github.com/users/wm4/following{/other_user}","gists_url":"https://api.github.com/users/wm4/gists{/gist_id}","starred_url":"https://api.github.com/users/wm4/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wm4/subscriptions","organizations_url":"https://api.github.com/users/wm4/orgs","repos_url":"https://api.github.com/users/wm4/repos","events_url":"https://api.github.com/users/wm4/events{/privacy}","received_events_url":"https://api.github.com/users/wm4/received_events","type":"User","site_admin":false},"created_at":"2015-02-18T21:24:28Z","updated_at":"2015-02-18T21:24:28Z","body":"Thanks for testing. Then I consider this fixed. Please report if you find any other issues."}}