How to save raw data (.bag) with lesser frame rate

[snmathur4]

---

Required Info
Camera Model	D400
Operating System & Version	Win 10
Platform	PC
Language	C#

Issue Description

I am saving a .bag using

private Pipeline pipeline = new Pipeline();
var cfg = new Config();
cfg.EnableRecordToFile("C:\temp\My_test111.bag");
var pp = pipeline.Start(cfg);
// rest of code ...
pipeline.Stop();

But my .bag file gets huge (GB) very quickly. I am not interested in so much data. I want to record about 1 minute but maybe only 10 frames per second. Is it possible to specify the frame rate for recording data to bag files? thanks

[MartyG-RealSense]

As well as supporting 30 fps on most resolution modes, 6 fps and 15 fps are also supported. So a good compromise may be to configure your stream to run at 15 fps and record the bag file as normal.

When doing the bag recording in the RealSense Viewer program, you can also now set custom save paths so that the file gets saved in a computer location where you have the most spare storage capacity.

[snmathur4]

Thanks for your reply. I tried your suggestion with this code:

Config cfg = new Config();
cfg.EnableStream(Stream.Depth, 640, 480, framerate: 6);
cfg.EnableStream(Stream.Color, Format.Rgb8, framerate: 30);
cfg.EnableRecordToFile(@"C:\temp\My_test111.bag");
pipeline.Start(cfg);

This code works fine, but when I change the Stream.Color to framerate: 6. I get this exception:

[MartyG-RealSense]

I think you need to use the code below for your cfg stream configuration lines:

cfg.enable_stream(rs2.stream.depth, 640, 480, rs2.format.z16, 6)
cfg.enable_stream(rs2.stream.color, 640, 480, rs2.format.rgb8, 30)

[snmathur4]

I am using C# and the naming is little different. Based on this example:
https://github.com/IntelRealSense/librealsense/blob/master/wrappers/csharp/cs-tutorial-2-capture/Window.xaml.cs

I also noticed following works good and created a good .bag file

cfg.enable_stream(rs2.stream.depth, 640, 480, rs.format.z16, 30)

but following creates a corrupt .bag file ("Bag unindexed") when I try to open it

cfg.enable_stream(rs2.stream.depth, 640, 480, rs.format.z16, 30)

[MartyG-RealSense]

Yes, sorry, I just realized that the C# format is different. My apologies!

Apparently, the unindexed bag error is related to a problem with how the bag recording is closed.

#2326

Though your code does conform to the suggestion in that discussion to close it with Stop if you are using the pipeline.

[snmathur4]

Yes! you're right. Just tried and seems like .bag file is created correctly with following. thanks!

pipeline.Stop(); 

But I am still have issues with this:

cfg.EnableStream(Stream.Color, Format.Rgb8, framerate: 6);

6 frame rate works for Stream.Depth but not Stream.Color

[MartyG-RealSense]

I found another case where someone had trouble with streaming color at 6 fps. No explanation was provided regarding why that may have been happening for that user though, unfortunately. It looks like it may have been a case where it got closed because the user stopped providing responses.

#2771

Does it work at 15 fps?

[snmathur4]

Yup! thank you 15 fps worked with 640 x 480.
Strange it doesn't work with 6 fps. I'll read through the post some more.
Thanks for your help!

[MartyG-RealSense]

Glad I could help!

I just did a test with your configuration in RealSense Viewer (640x480 at 6 fps for depth and color, z16 for depth and rgb8 for color). The most noticeable event was that when a 6 fps color stream was started, a 'no frames received' error briefly flashed up and then the color stream started running normally. This error did not occur at 15 fps and above.

[snmathur4]

Oh interesting, maybe I'll try to just ignore first few frames or wait couple seconds before retrieving frames. Will see if that helps.

I tried both Color and Depth at 15 fps, and for 1 minute I am getting 1 GB of .bag file. This is acceptable to me.