D400 onboard compression.

[SMali10]

During the multicamera webinar from September of last year, it was announced that onboard compression would be coming to the D400 series. This feature would make it possible to have more throughput on a single USB bus, and reduce the complexity of a synced multicamera setup.

Is this feature still planned for an upcoming release? Or should developers plan on alternatives?

Would the compression work for all video channels including color and infrared? Or just depth?

Thanks!

[MartyG]

Intel mentioned in the webinar that at a future date, x3 compression of data would be enabled. This would allow more channels and more cameras to be supported. Also, a new 'Modified Huffman' lossless compression would enable the streaming of higher resolution and FPS on USB2, and more channels in multi-camera configurations.

I don't think these features have been activated yet, and unfortunately I do not have knowledge of how they work or when they will become available. Intel did though add a Compression API in late 2018 that is discussed in the link below.

https://github.com/IntelRealSense/librealsense/issues/3594#issuecomment-477012658

[SMali10]

As always, thank you for the fast reply Marty :)

Compressing bag files is interesting.

As I mentioned in my initial post I am aware of the potential benefits of streaming compression, and that it has not been implemented yet.

To be clear my question to Intel is if this feature is still planned for release, or if developers should find alternative solutions.

Thanks again.

[MartyG]

A member of Intel's support team will be best placed to give an official reply about these features. In the meantime, there are a number of ways to do compression with RGB-D streams. Some examples are discussed in the link below.

https://forums.intel.com/s/question/0D50P0000490DvWSAU/compression-formats-for-rgbd-streaming?language=en_US

[SMali10]

Thanks Marty,

Again that’s interesting, but off topic. My question is about onboard compression on the D400, for the purpose of reducing the load on USB throughput, and making multicamera capture bandwidth more efficient.

I am only stressing this point so that if/when an Intel representative replies, they do not think this question has been answered. Thanks again and I hope you understand.

[Eliza_D_Intel]

Hello SMali10, Thank you for your interest in the Intel RealSense D400 Series. We have escalated your question to the RealSense Team. We will provide you an answer as soon as possible. Thank you, Eliza

[Eliza_D_Intel · Accepted solution]

Hello SMali10, Thank you for your patience! The engineering team is still working on compression and we don't have a timeline for its release. Compression is for depth only and 3 - 4x lossless. Thank you, Eliza

[SMali10]

Thanks for the update Eliza, I really appreciate it.

Is there any way to request compression for other streams like color and IR? The on board depth estimation of the D435 is not very good, so my setup needs to do custom stereo matching on the IR frames.

[Eliza_D_Intel]

Hello SMali10, I will forward your request to the RealSense Team. Thank you!