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= Audio Mapping: Synchronization =

Because the GPS track and the audio recording will not have been started simultaneously you will need to synchronize. You may also have paused the recording part way through, so you would need to re-synchronize at that point too.

There are two ways of synchronizing. Which is easier to use depends on whether you are synchronizing to a waypoint you explicitly created in the GPS for the purpose, and also whether you started the recorder before or after your GPS started recording its track.

In both cases you will need to use the [wikitr:/Help/Menu/Audio audio controls] to pause, play back etc. and you
can drag the orange play head marker around to jump to a particular point in the recording.
     * if you don't see an orange play head arrow moving along the track while you play audio, make sure the 'Display live audio trace' option in [wikitr:/Help/Preferences/Audio Audio Preferences] is on.

== 1. Locate audio cue first, ground location second ==

  1. Play your sound track from the beginning. You can start it with [[JOSMImage(audio-playpause,20)]] [wikitr:/Help/Action/AudioPlayPause play] or by clicking on the first audio marker.

  2. When you hear your synchronization cue ("NOW!"), [[JOSMImage(audio-playpause,20)]] [wikitr:/Help/Action/AudioPlayPause pause] the play back.

  3. While holding the '''{{{Shift}}}''' key down, drag the orange play head arrow to the place where you want to synchronize (where you were when you said your cue). This can either be an existing audio marker or just a point on the GPS track.
     * if you don't choose an existing marker, one will be created for you at that location.

== 2. Locate ground location first, audio cue second == #LocFirstAudioSec

For this method, you need an audio marker at the location where you will synchronize. If you are working with GPS way points, you should already have one. You can also add one explicitly using [wikitr:/Help/Action/MakeAudioMarkerAtPlayHead Make Audio Marker At Play Head] on the Marker Layer's context (right mouse button) menu.

  1. Play your sound track by clicking the icon for the waypoint you made at the synchronization cue.

  2. When you hear your synchronization cue ("NOW!"), [[JOSMImage(audio-playpause,20)]] [wikitr:/Help/Action/AudioPlayPause pause] the play back.
     * if you started the recorder ''after'' getting a GPS fix, you will need to [[JOSMImage(audio-back,20)]] [wikitr:/Help/Action/AudioBack jump backwards] in the sound track. Don't click on an earlier marker, if any, to do this, as that would synchronize to the wrong marker.

  3. Select [wikitr:/Help/Action/SynchronizeAudio Synchronize Audio] on the context menu for the Marker Layer.
    * The play head should jump back to the marker, and when you play the marker you should hear your "NOW!" cue. Clicking on other markers should offer the audio you recorded when you made that marker.

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Back to [wikitr:/Help/AudioMapping Audio Mapping][[Br]]
Back to [wikitr:/Help Main Help]