GPV Systems - Global Positioning Video GPS Software

Most GPS devices are capable of creating an “Active” track log as well as “Saved” track logs. GPVlite will download and display all active and saved track logs. However, only the active track log points retain their time values so only the active track logs will be able to be played on GPVlite.

GPS devices are typically capable of using a distance based or a time based track log interval. GPVlite will refresh the display of GPS data at the same interval as your GPS track log is set to. For the highest accuracy and most consistent display refreshes, it is recommended that you use a time based track log interval. The interval should be set to the smallest amount possible. To determine the smallest interval, you must know the following info: 1. How many track points your GPS can store in the active track log and 2. How long you plan on recording data. To determine how long you can log track points before your active track log becomes full use the following calculation

(Number of track points / 3600) X interval_sec = Available time_hrs

b. Setting and Synchronizing your GPS and Camcorder’s Time

Before synchronizing your Camcorder time to your GPS time, make sure that your GPS is set to the proper time zone. It does not matter whether your GPS is in 24hr or 12hr mode.

To synchronize the Camcorder to the GPS, simply start the process of setting the Camcorder’s time. Set the hour and minute to match the hour and minute displayed on the GPS. Then, set the seconds on the camcorder to be 10 seconds ahead of the GPS but do not press the button to finish time setup. Wait for the GPS time to catch up to the camcorders time. At the precise moment that the seconds on the GPS matches the seconds on the camcorder, press the button to finish setting the time. You should be able to get the GPS and Camcorder synchronized within ½ a second using this method.

2. Editing Your Video Footage

a. Turning your Camcorder Tape into a Digital File

In order to view your video footage with GPVlite, you need to get it onto your computer. Your computer needs to have a video capture card and software. There are a couple of rules you should follow when editing your footage.

First, you should edit your footage such that each individual block of time is contained in it’s own file. For instance if you recorded a total of 1hr of footage but you started and stopped recording such that the actual times that you recorded were from 12:00-12:30 and 3:00-3:30, you should create 2 digital files. One file should contain the footage shot from 12:00-12:30 and the other should contain the footage from 3:00-3:00. This will make GPS and Video synchronization easier.

If you choose not to split each block of time into it’s own video, you should display the time stamp from the original recording for at least one video frame at the beginning of each time block in the file. This visual time reference will make it easy to synchronize the video to the GPS track.

3. Loading, Saving and Editing GPS Tracks with GPVlite.

a. Downloading Tracks from your GPS

GPVlite is capable of downloading the active track log from most Garmin and Magellan GPS devices. To download you tracks do the following:

1. Plug your GPS into your computers serial port.

2. Turn your GPS on

3. Open GPVlite. From the “Track” menu click “From GPS”.

4. Choose the COM port and GPS Devise and click “OK”

Your GPS track log should begin downloading. There is no status bar during Magellan downloads. Downloads can take a while so be patient. Once downloading is complete, the “Track Segment Selection” dialog box will appear and you will have the opportunity to edit your track (see section d below).

b. Loading GPS Tracks from Existing Files.

With GPVlite, you can import existing GPX, NMEA and MapSource log files. To import these files:

1. Open GPVlite. From the “Track” menu choose the file type you want to import.

2. Browse to the file you want to import and click “Open”.

Note: You can also import GPX files using the “Add Track from GPX” toolbar icon.

c. Saving GPS Tracks as GPX files

GPVlite allows you to save your downloaded GPS track to a GPX file that can be stored on your computer for future use. To save your GPS Track:

1. Download the track log from your GPS as shown above

2. Once the track is loaded, from the “Track” menu click “Save to GPX”

Note: You can also save using the “Save to GPX” toolbar icon.

d. Editing your GPS Track

In many cases, your track will contain erroneous or extra track points that need to be removed. Editing is done in the “Track Segment Selection” dialog box. This box will appear automatically at the end of the GPS downloading process. You can edit your track at anytime by clicking “Edit Track” from the “Track” menu. The editing options are Delete, Crop, Join and Split.

· Delete: Deletes the chosen track segments.

· Crop: Deletes the track segments that are not chosen.

· Join: Joins two or more track segments.

· Split: Splits a track segment at a user selectable GPS time.

Editing your track within GPVlite will not affect the GPX file stored on your computer. If you make errors editing a track, you can reload the original GPX file and start again. If you would like to save the edited track you must “Save to GPX”.

4. Loading your Video file into GPVlite

GPVlite is capable of playing any video file that your computer is capable of playing otherwise. To load the video file simply click on “Add Video” from the “Video” menu or use the “Add Video” toolbar icon.

Note: Once the video file is loaded, you may need click on one of the video controls or the video slider to get it to display properly.

5. Synchronizing your Video & GPS data in GPVlite

a. Synchronization Using the Video Time Stamp

If you have edited your video such that you have a visible time stamp on some or all of the frames, you can use this method to synchronize the video and GPS data.

1. Load your GPS and video data into GPVlite.

2. Use the video controls and slider to move the video to a frame that has a visible time stamp.

3. Open the Synchronization dialog box by clicking on the “Synchronize” toolbar icon or choosing “Synchronize from the “Video” menu.

4. Choose the date and time that matches the current video frame date & time.

5. Make sure the “Play Track” check box is checked and click “OK”

The Video and GPS data are now synchronized and the video controls should now be controlling the playback of both video and GPS.

Note: A typical video is shot at 30 frames per second. Therefore, there will be 30 consecutive frames that all show the same time stamp. For the most accurate synchronization, be sure to set the video to the first of the 30 frames with that time stamp.

b. Synchronization using the GPS Time Stamp

If your video does not have a visible time stamp you can synchronize by advancing the GPS track to a certain known event or location and then advancing to that point on the video. Typical events that you could synchronize to are starts, stops and turns at known locations such as intersections, trailheads and traffic signals. Follow these steps to synchronize using this method.

1. Load only your GPS data into GPVlite. There must not be a video present.

2. Use the Video controls and slider to advance the GPS track to the known event you want to sync to.

3. Load your video file.

4. Use the video controls and slider to find the frame in the video that corresponds to the known event point you had previously moved the track to.

5. Open the Synchronization dialog box by clicking on the “Synchronize” toolbar icon or choosing “Synchronize from the “Video” menu.

6. Choose the date and time that matches the GPS date & time displayed to the right of the video slider.

7. Make sure the “Play Track” check box is checked and click “OK”.

c. Creating Multiple Synchronization Points.

With GPVlite you can create multiple synchronization points. Either of the two synchronization methods above can be used to create multiple synchronization points within the same file.

Keep in mind that if you choose to use the GPS method above, you will need to write down the time and description of each of your known event points before loading the video file. Once you’ve loaded a video file, you will not be able to control the GPS track using the video controls. Make sure that the “Play Track” check box is checked for each synchronization point.

d. Synchronization Examples

In most situations, the GPS data will be more complete than the video data for a given trip. In the event that you have a gap in the GPS data for a particular video file, you may need to create multiple sync points with “Play Tack” either checked or unchecked.

Example 1: Your video file is a solid block of time from 10:00-10:30. You only have GPS data equal to or greater than the entire video time (IE: 10:00-10:30, 9:45-10:45 etc.). In this case, you would create 1 sync point.

Sync Point	Time	“Play Track”
1	Any	Checked

Example 2: Your video file is a solid block of time from 10:00-10:30. You only have GPS data from 10:00-10:10 and 10:20-10:30. In this case, you would create 3 sync points.

Sync Point	Time	“Play Track”
1	10:10	Checked
2	10:10 + 1 frame	Unchecked
3	10:20	Checked

Example 3: Your video file is multiple blocks of time. For this case we’ll use 2; from 10:00-10:30 and from 11:00-11:30. You have GPS data from 10:00-11:30. in this case you would create 2 sync points

Sync Point	Time	“Play Track”
1	Any time up to 10:30	Checked
2	Any time after 11:00	Checked

6. GPVlite menus and Toolbars

For a view of the GPVlite Toolbars, click here