Audio sync problem
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Audio sync problem
Hi - we are using ELAN in a controlled environment - i.e. the University IT department controls what is on the computers.<br><br>We are having a couple of problems, and I need some under-the-covers technical info so I can get the right people helping me solve the problems.<br><br>The environment is Windows XP, and we are working with 'frozen images' (i.e. we can install new software, but the system reverts back to the frozen image on each reboot).<br><br>There are two problems at present:<br>1) On everyone's laptops and home machines, the clips play fine in ELAN, but on the University machines, they frequently lose audio sync (in ELAN). I suspect that the problem has to do with which codecs are installed on the machine, but I have no idea how to find out what is missing (or there that shouldn't be there).<br><br>2) MP4's work fine on home computers, but don't work with ELAN on the University machines. <br><br>My questions are along these lines:<br>a) how do I go about figuring out, for any given file type, what codecs should be present for them to work?<br>b) Can I do that in reverse? I.e. given the installed codecs, can I figure out what formats need to be present in the MP4 container so that they will work? And, if I do figure it out, how do I convert to that format? (we've been using the tool "Format Factory" to do our conversions).<br>c) What is the underlying engine that ELAN uses to play the video - is it WMP? (If it is WMP, am I right in assuming that if I can play a video correctly in WMP, then it should play correctly in ELAN?)<br><br>I need some help - I have access to (people) resources - but as of now, I don't know what to request from them.<br><br>Bruce Anderson<br>Glendon / York University<br><br>
Re: Audio sync problem
If you have opened an eaf file in ELAN and then exit ELAN, you can find some information on the media player and the codecs that have been used in the log file. The log file (elan0.log or elan1.log, look at the dates) can be found in the folder <user_home>\.elan_data\
You could start with comparing the log files of some of the machines. The log file might also contain useful error messages. The logs might tell you what you have to install (or change) on the University machines.
ELAN's first choice for playing a file is based on DirectShow (read WMP), next QuickTime is tried and finally Java Media Framework. mp4 files on Windows will likely be played by QuickTime, unless you have a codec installed that supports mp4.
If a video has succesfully been opened in ELAN, you can check which media framework is actually playing the file by right-clicking the video and choosing "Player Info". In order to be able to play QuickTime files in ELAN, QuickTime has to be installed before ELAN is installed. So, this could be another check; are the same player frameworks used on the University PC's and on the laptops.
-Han
Release of ELAN 4.3.0
