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Femto Mega timestamps synchronization when working as POE devices

Open moversevlad opened this issue 2 years ago • 5 comments

I've a setup of 2 Femto Mega devices and I use a syncbox to synchronize them. When I am using the USB interface, the hardware timestamps seem to be updated despite the fact that hardware timestamp seem not to match usb_hw_sync_confirm

but when I am using the POE interface, a) hardware timestamps are not synced to host PC b) system timestamps are also off poe_sync

(I am moving a retro-reflective object in the scene at high speed, this is what you see in the pictures)

You can find the code here, which is a modified version of the MultiDeviceSync example to support PoE

moversevlad avatar Oct 19 '23 12:10 moversevlad

The v1.1.5 version of Femto Mega device firmware can only obtain the startup time of the device through POE connection. This issue can be resolved by updating the firmware to v1.2.6. This version of firmware will be officially released in the next few days, and I will tell you the download link here.

hzcyf avatar Oct 23 '23 02:10 hzcyf

Hello, on top of this question. Lets suppose we're able to synchronize the cameras and the timestamps of the devices are synced with the host PC. After that we want to group frames across all cameras, based on the timestamps. Should I use device timestamps or system timestamps?

moversevlad avatar Oct 30 '23 08:10 moversevlad

Hello, on top of this question. Lets suppose we're able to synchronize the cameras and the timestamps of the devices are synced with the host PC. After that we want to group frames across all cameras, based on the timestamps. Should I use device timestamps or system timestamps?

Using device timestamp is better, which is the timestamp when the data frame is exposed, while system timestamp is the timestamp after the data frame is received by the SDK.

hzcyf avatar Nov 01 '23 01:11 hzcyf

Amazing, thank you. It seems that I get quite some frames that do not match their device timestamps. Screenshot_4 This is an example of this case. Previous too that frame, I get HW synced frames, both on what I see, as well as on their device timestamps. Seems like I get quite high percentage of frames that are not synced, is there such an issue in the backlog / have anyone observed such behaviour?

moversevlad avatar Nov 01 '23 08:11 moversevlad

Please download the firmware, upgrade tool, and upgrade documentation, and then follow the upgrade documentation to perform firmware upgrades. https://github.com/orbbec/OrbbecFirmware/releases/tag/Femto-Mega-Firmware @moversevlad

zhonghong322 avatar Dec 23 '23 05:12 zhonghong322