Problem with IMX415 USB camera

[perdrix]

Using another application the (Collimation Circles4.0 Beta 1), then video from this USB 4K webcam is free flowing. I don't know what frame rate it is using, but there are no stutters or other issues.

If I connect to it using SharpCap 4.1 I'm lucky to get 0.1fps and it often doesn't update for long periods.

Exposure is set to auto.

Any thoughts? Thanks, David

[admin]

Hi David,

I guess the first thing to check would be the camera settings match in both applications - resolution, colour space, etc. I would also set exposure to a manual one if possible, as in most cases a long exposure will reduce the frame rate accordingly.

With a directshow camera, there are really no adjustments hidden behind the scenes - SharpCap gives you access to pretty much everything that you can change, so you ought to be able to match the configuration of the other application (providing that the other app lets you *see* the config it is using).

It does sound odd to have very low (sub 1fps) rates unless you have long exposures though. Do you have a link for the exact model/make of camera?

cheers,

Robin

[perdrix]

The "other app" simply grabs the video stream from the camera which I am sure is a DirectShow device.

I had SC set to use MJPEG so it should be able to grab the frames as the camera dishes them (or does SC use "still capture" when in preview mode)? Maybe that's the problem?

It was an ELP-USB4K03-H110 webcam

[admin]

Hi,

there is no real still mode for webcams - you set them up in video mode and grab a frame out of the video stream if you want a still image.

SharpCap probably introduces a fair bit more CPU overhead than other webcam software. The normal approach is to tell DirectShow to open the camera and where in the window to render the video, and then directshow handles the whole pipeline from camera to screen. SharpCap bypasses a lot of that and basically feeds the frames from the video into the same processing/capture/display pipeline as frames from any other type of camera. Without that approach a lot of SharpCap features would be impossible to use on webcams, but you do pay for it in terms of CPU loading.

Unfortunately that camera is a bit more expensive than I'd want to pay to buy one to try out an issue like this, sorry. I would suggest trying lower ROI, manual exposure and different colour space options to see if you can make any adjustments that give you a higher frame rate. Also, just to be sure, open the camera with the <CTRL> key pressed at least once to stop SharpCap from restoring previously used settings for the camera. For instance there is a 'frame rate limit' control that will deliberately drop frames as required to get down to the specified limit. If you have previously set that to some value it could be being restored each time you open the camera.

cheers,

Robin

[perdrix]

I just tried it again, and it started out at a reasonable frame rate but than dropped away until after 15 frames the rate was 0

Does the attached log help?

Log_2026-02-16T14_50_36-32936.zip

(12.22 KiB) Downloaded 6 times

David

[perdrix]

If it gives any clue, Sharpcap 3.2 works pretty well giving about 12-15fps continuously at 3840x2160, and around 20fps as 1920x1080.

Sharpcap 4.0 has the same problem as 4.1

[perdrix]

Robin,

Did the trace I uploaded give any clues about the problem? Did the fact it works correctly with 3.2 suggest anything?

Would posting the camera to you be helpful?

David

[admin]

Hi David,

the log doesn't really point to anything specific, but does rule out a few possibilities like CPU resourses becoming overwhelmed in the UI thread, etc (those would be logged if they happened). I suspect that what is happening is that the DirectShow graph is stopping sending frames through to the SharpCap code that receives them for some reason. There have been lots of changes over the 3.2 => current period in how that DirectShow graph is set up, so it's hard to work out what might cause that.

We do have a bit of a chance based on the fact that 3.2 works - could you try the very first version of SharpCap 4.0 (4.0.7888 from the bottom of the 4.0 downloads page). If that works by any chance then we can narrow down over the version history from that version up to 4.0.9562 to see where the breakage happens and then pin down the problem to a hadful of commits. Even knowing that it doesn't work halves the search space for the change that caused the problem, although it does also potentially put it into the 'a fundamental change in how webcams are set up' area that may be hard to resolve.

It may come down to getting the camera or a similar one into my hands in the end, but not quite there yet. BTW, have you managed to test on another PC, just in case that shows different results. I tested here with the highest resolution webcam I could find (actually a ToupTek camera running via DirectShow at ~6000x4000) and that worked but in RGB colour space. I found another webcam that does do MJPG which also worked, so I am drawing a blank so far on seeing anything similar.

cheers,

Robin

[perdrix]

If I try to DL that release (64 bit) I get a display in the browser that says:

Error: Invalid ID format. 4be7b1a8-074c-788a-81fd-8d6a839c0aa8_x64

David

[perdrix]

I just tried with SC 4.1 and my Altair GPCam2 GP224C (IMX224), using the driver installed by the latest version of Altair Capture. I'm getting the same issue - stupidly low frame rates.

SC 2.9 (on that system) is fine, as is 3.2 (over 10pfs at 1280x960 RAW12)