USB Camera in JB 4.2.2-1.0.0 SabreSD

[Chris1z]

I've enabled the USB camera on JB 4.2.2 SabreSD board using the following patch.  When I test it with a Logitech Webcam C250 and the "Camera" app, I see a lot of video glitches.  Pointing it at a static location, I see glitches every 5-10 seconds.  And if I wave my hand in front of the camera the video glitches are worse.

Is there a way to improve the USB video decoding performance?

diff --git a/sabresd_6dq/BoardConfig.mk b/sabresd_6dq/BoardConfig.mk

index 8ecf4a7..ef53f05 100755

--- a/sabresd_6dq/BoardConfig.mk

+++ b/sabresd_6dq/BoardConfig.mk

@@ -97,6 +97,8 @@ USE_GPU_ALLOCATOR := true

# camera hal v2

IMX_CAMERA_HAL_V2 := true

+BOARD_HAVE_USB_CAMERA := true

+

# define frame buffer count

NUM_FRAMEBUFFER_SURFACE_BUFFERS := 3

diff --git a/sabresd_6dq/init.rc b/sabresd_6dq/init.rc

index 4420c07..70f7cae 100755

--- a/sabresd_6dq/init.rc

+++ b/sabresd_6dq/init.rc

@@ -52,10 +52,10 @@ on boot

     #For landscape mode, orient is 0

     #For portrait mode, orient is 90

     #the android before honycomb are all in portrait mode

-    setprop back_camera_name ov5640_mipi

+    setprop back_camera_name uvc

     setprop back_camera_orient 0

-    setprop front_camera_name uvc,ov5642_camera,ov5640_camera

-    setprop front_camera_orient 0

+    #setprop front_camera_name uvc

+    #setprop front_camera_orient 0

     # Set OpenGLES version

     setprop ro.opengles.version 131072

[karina_valencia]

Re: USB Camera in JB 4.2.2-1.0.0 SabreSD

AndreSilva Jul 5, 2013 6:28 PM (in response to imxcommunityscout)

Maybe this can help:

https://community.freescale.com/thread/301961

Re: Re: USB Camera in JB 4.2.2-1.0.0 SabreSD

[Chris1z]

Thank you Karina, but this was not my issue.  I can connect the UVC camera just fine and see video.  I am more concerned with the video performance and video glitches we see when using the camera.

[Ivan_liu]

hi, it should be eletromagnetic compatibility issue.

please take another usb camera to have a try.

[Chris1z]

Thanks for your replay Xiaowen.  I've tried 3 other cameras with the same issue:

Creative Live Cam VF0690

Microsoft LifeCam Cinema

Our custom USB camera

[Ivan_liu]

hi Chris1z

please refer to our Release Note to chose the usb camera supported in our platform.

Media - USB Camera

Y

Y

Y

Logitech: C250 E3500

The usb camera you used to do test is not supported in our platform.

[9crkzhou]

where is this Relese Note ?

can you give me a link? or a full name

[Chris1z]

The release notes document is Android_Release_Notes.pdf.  It's found in the "docs" directory of the jb4.2.2-1.1.0-ga Android release.

[Chris1z]

Hi Xiaowen,

Please read my original post.  I tested it with C250.  I only mentioned the other cameras when you suggested trying other cams.

Chris

[Ivan_liu]

hi Chris1z,

what I mean that please try other usb cameras that suppported.

Even the same kind usb cameras may have different electromagnetic response.

please ignore the usb cameras that not supported.

Xiaowen

[Chris1z]

Xiaowen,

I only have access to one C250.  I'm not sure I understand how this could be an EMI issue.  It seems more like a video decoding issue.  Can you elaborate more on what the electromagnetic issue would be? Would other USB devices on the bus have this problem? Is there something we can probe?

Thanks,

Chris

[Ivan_liu]

hi Chris1z,

Because we have met the similar problem when do preview.

It is ok after we replaced it with another usb camera.

So, can you make sure that it is ok when do preview.

Does the issue only happen with recording.

When do recording, it also do preview.

So, the issue you mentioned happens on preview output or the encoded video file when do recording. 

BRs,

Xiaowen

[Chris1z]

Xiaowen,

We would see this issue on the preview and remote side of a Skype call.  I'm still trying to understand the EMI issue...we have 4 different camera vendors that exhibit this problem?  Is the issue on the USB bus or are you saying the actual cameras are faulty?  Would it happen to the "bad" camera if it was hooked up to a PC?

Thanks,

Chris

[Ivan_liu · Accepted solution]

Hi Chris1z,

The usb camera is not a "bad" camera. It is ok when connected to PC.

It should be some other module like WIFI with high frequency impact the usb bus receiving data from usb camera.

Or, it may be usb camera does not have good anti-jamming to high frequency.

BRs,

Xiaowen