Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Any discussion on using LapTimer. Please use this forum in case you need guidance on how to use LapTimer or perform a certain operation
Post Reply
Dubbedown
20 or more Posts ★★★
20 or more Posts ★★★
Posts: 161
Joined: Wed Jan 04, 2012 9:36 pm

Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Dubbedown »

I realize the current limitations around trying to connect more than 1 action cam but say I had 2 iOS devices that I ran in parallel, each connecting to its own action cam. Assuming each external video linked successfully to lap timer, would the linked video lap of one device sync up to the same start and end points as the other video? The goal would be to overlay the 2nd action cam footage onto another without manual syncing.

For example say I have an iPod touch using gps connected to GoPro3 and separately an iPhone (internal gps) connected to a GoPro4.
User avatar
Harry
Site Admin
Site Admin
Posts: 10518
Joined: Sun Sep 12, 2010 10:32 am
Location: Siegum, Germany
Contact:

Re: Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Harry »

You will need to adjust the sync point by +- 1s. There are certain runtime effects which make LapTimer start earlier or later. This can be compensated locally (so LapTimes will be within the usual accuracy range when comparing both), but the video start and sync will vary.

- Harry
Image Image Image Image
Dubbedown
20 or more Posts ★★★
20 or more Posts ★★★
Posts: 161
Joined: Wed Jan 04, 2012 9:36 pm

Re: Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Dubbedown »

Harry, let me clarify... what I meant was, would 2 separate iPhones yield the same start and end times with their respective videos?
User avatar
Harry
Site Admin
Site Admin
Posts: 10518
Joined: Sun Sep 12, 2010 10:32 am
Location: Siegum, Germany
Contact:

Re: Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Harry »

Yes, I have understood. The answer is "You will need to adjust the sync point by +- 1s". Or in other words "No".

- Harry
Image Image Image Image
Dubbedown
20 or more Posts ★★★
20 or more Posts ★★★
Posts: 161
Joined: Wed Jan 04, 2012 9:36 pm

Re: Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Dubbedown »

Ok great, thanks for confirming. I knew in general sync points between video and phone needed +/- 1 sec adjustments.

So my next question is, if I import the 2nd action cam video (connected to iOS device A) onto iOS device B, would the imported video retain all the lap sync points under its "video details"? Or would I need to export video lap by lap and synch the laps manually onto device B.
User avatar
Harry
Site Admin
Site Admin
Posts: 10518
Joined: Sun Sep 12, 2010 10:32 am
Location: Siegum, Germany
Contact:

Re: Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Harry »

The sync point is stored as part of a lap, not a video. It is probably easier to copy the video and use the add video function to add it as a second video to your lap. You can "copy" the sync information by reading the value on phone B and enter it on phone A.

- Harry
Image Image Image Image
Dubbedown
20 or more Posts ★★★
20 or more Posts ★★★
Posts: 161
Joined: Wed Jan 04, 2012 9:36 pm

Re: Does Running 2 iOS Devices in Parallel Result in Same Video Sync Points?

Post by Dubbedown »

Harry wrote:The sync point is stored as part of a lap, not a video. It is probably easier to copy the video and use the add video function to add it as a second video to your lap. You can "copy" the sync information by reading the value on phone B and enter it on phone A.

- Harry
Right, makes perfect sense... because as long as both iOS devices (and corresponding external cameras) start & end same time the sync point of video A should be comparable with video B. :)
Post Reply