Menu

help with frame-by-frame sync (JACK)

Help
2009-06-29
2013-05-14
  • John Detwiler

    John Detwiler - 2009-06-29

    Hi, all,

    I'm new to xjadeo, using it with Ardour (via JACK).  Everything is installed and working well, except for one problem....

    As I manually advance the Ardour 'playhead', frame-by-frame, the xjadeo display advances only about every 12th frame.  This makes it impossible to sync a sound event (SFX) to the specific frame of the corresponding visual event.  I see the timecode display on both Ardour and JACK is advancing frame-by-frame, but the xjadeo window doesn't change.

    All parameters are at their out-of-the-box defaults, since I haven't learned what to adjust.  But I notice options such as 'Frames per period' (in JACK 'setup') and 'JACK Latency' (in Ardour), both set to 1024 -- presumably the same parameter. 

    On startup, xjadeo says 'no TTF font, so  no OCD'; so maybe I need to fix that first in order to see what's happening??

    Any suggestions at this point?

    Thanks!

    === console output from xjadeo at startup ===
    no TTF font found. OSD will not be available until you set one.
    original frame rate: 29.97
    length in seconds: 3517.66
    total frames: 105424
    movie size:  720x480 px
    Video output: XV - X11 video extension
    Xv: NV17 Video Texture: ports 280 - 311
    XV: using YUV420P + Xvideo extention (I420)
    enabled drag-DROP support.
    connected as jack client 'xjadeo-0'
    =======

    running Fedora 10
    Ardour has 'time master' turned ON

     
    • Robin Gareus

      Robin Gareus - 2009-06-29

      Hi,

      When moving the playhead manually (in ardour) xjadeo directly follows that, when pressing "play" xjadeo will update the screen at a given rate only (default is 10fps - to keep the CPU low) - you can override that with
      <pre>
         xjadeo -f 25 <video-file>
      or
         xjadeo -f -1 <video-file> # uses the file's FPS
      </pre>

      ..or with the spin-button in qjadeo.

      That it only takes every 12th frame is weird. xjadeo sync is regularly tested - also with 29.97 drop-frame files.

      I hazard a guess that it is related to the video-codec of your movie file. Can you post the output of `xjinfo -v <video-file>`?

      You may just miss the "-K" option which enables xjadeo to seek to non-keyframes:
      <pre>
        xjadeo -f -1 -K <video-file>
      </pre>

      As for the OSD (on screen display of timecode) - your distribution or packager seems to have  messed that up.  You can specify a font in
      $HOME/.xjadeorc

      Just type this in a terminal:
      <pre>
      echo "fontfile=/usr/share/fonts/truetype/freefont/FreeMonoBold.ttf" >> ~/.xjadeorc
      </pre>

      A complete example config file can be found at
      http://xjadeo.svn.sourceforge.net/viewvc/xjadeo/trunk/doc/xjadeorc

      BTW. The qjadeo GUI provides an interface to set the  OSD-font, screen-update-fps and frame-seek-mode.

      Your ardour settings seem to be OK,  don't forget  to change "Options -> Timecode fps" to 29.97 in ardour's menu for your project ;)

      good luck,
      robin

       

Log in to post a comment.