save single frame can't get depth data

[soarwing52]

Required Info
Camera Model	{ D435 }
Firmware Version	(latest)
Operating System & Version	Win 10
Kernel Version (Linux Only)	N/A
Platform	PC
SDK Version	{ 2.19.0 }
Language	{ python }
Segment	{others }

Issue Description

<Describe your issue / question / feature request / etc..>

Hi,
I was trying to save single frame with the save_single_frameset() in python

I have the same time the recorder. but the depth file I got have no depth data

the first one is with recorder

and the second one is with save_single_frameset

the depth data with recorder is normal, and the one with single frameset is always 0.00

and I tried to read the recorded bag file and apply save_single_frameset on the frame, also got 0.00

the code I used is

saver = rs.save_single_frameset()
frames = pipeline.wait_for_frames()
saver.process(frames)

I got this from #2588 , #3671 and #3704

If this is the right way or should I add some other lines?

https://drive.google.com/open?id=1gwyfJPE9nwYzyF-xGc4gqyrfuHttErim
the frameset and recorder file is here

[soarwing52]

The difference seems to be at the streaming,

which in normal recorder has streams but in the single frameset came to be Unkown Stream

would it be the issue?

[soarwing52]

@RealSenseCustomerSupport
I’d kindly ask why is this issue closed?
I mean I saw the example in the three other issues and tried to use it
but my issue is not mentioned in the other three issues
Can you shortly answer if it’s possible?

[soarwing52]

@RealSenseCustomerSupport
Hi, I'm still working on the save_single_frame function but still don't have any clue.
I would like to ask how to get the depth measure or the 3D coordinate x,y,z of the bag saved by this function, how it can be achieved?

the rs.reproject doesnt work on it