Android Webcam Library
This project is an Android library to provide an API to access an external USB webcam that supports UVC. The library provides an in-process service (
WebcamManager) so that multiple parts of an application can share the same webcam.
The library also provides an example View that can be used directly in a layout, the
Instead of an FAQ, if you can't get the library to work, try one of these suggestions. Unfortunately video is fairly non-standard across Android OS builds and web cams, so I can't provide very good support.
I don't have a /dev/video0 on my Android tablet or phone.
You may need to change the device name in code to match what your camera appears as in the filesystem (#5).
My device is missing the kernel drivers.
A tip from Borja:
I write you again because finally i managed to have external webcam working on my device. I's not a v4l2 related problem. I's because samsung devices do not have uvcvideo module in their kernel. All new devices have v4l2 intalled in kernel but not uvcvideo.ko that is the driver (module) to get comunication between linux kernel and uvc compliant web camera. I had to recompile a custom kernel to enable USB_VIDEO_CLASS option. With new kernel i have no problems to get frames from my camera with an app named dashcam. Now i'm going to test openxc/android-webcam to try get video in my app.
I get an error about insufficient permissions on the video device
Make sure the
/dev/video0 file has permissions of at least
0660, is owned by the
media user and the group
camera. Also add the
CAMERA permissions to your app's manifest.
NativeWebcamJNI(2427): VIDIOC_DQBUF error 9, Bad file number
Based on #13, try changing this:
// Change this //*fd = open(dev_name, O_RDWR | O_NONBLOCK, 0); // To this: *fd = open(dev_name, O_RDWR);
- Android SDK
- Android NDK
- Android Webcam library
- USB Webcam supporting UVC and a 640x480 resolution in the YUYV format.
- Clone the Git repository
android-webcam/android-webcam-libraryfolder to compile the native library
- Reference the library from your Android application
To install the library to your local Maven repository, so other apps can reference it:
$ cd android-webcam $ cd android-webcam-library; ndk-build && cd .. $ mvn install -pl android-webcam-library -am
To install the example application, first install the library, then:
$ mvn package android:deploy android:run -pl example
To just display the webcam image, add this to your app's layout:
<com.ford.openxc.webcam.WebcamPreview android:id="@+id/cp" android:layout_width="fill_parent" android:layout_height="0dip" android:layout_weight="1"/>
If you want to modify the image at all, subclass
WebcamPreview and override the
run() method to make any modifications to the iamge before rendering it to the canvas. The
WebcamManager service has a
getFrame() method which returns a Bitmap of the latest frame from the camera.
USB Webcam Support
To use a USB webcam in Android, the kernel must be compiled with
V4L2. Many late-model Android versions (4.2 and possibly 4.1/4.0) already have this enabled.
If the file
/dev/video0 appears on the device when you plug in a video camera, then you've got
If you have
/dev/video0, check the permissions in adb:
$ adb shell shell@android:/ $ ls -l /dev/video0 crw-rw---- media camera 81, 0 2013-02-25 10:31 video0
If the file is at least
0660, owned by the
media user with the group
camera, you're good to go.
CAMERA permissions to your app's manifest:
<uses-permission android:name="android.permission.CAMERA" />
Tested and Working
- Toshiba Thrive 10.1"
- Google Nexus 7
Tested and Not Working
- Galaxy Nexus (might not have enough power to start webcam)
If your Android version and device doesn't have include
V4L2 support, you'll need to load a custom Android ROM and configure the kernel with these options:
CONFIG_VIDEO_DEV=y CONFIG_VIDEO_V4L2_COMMON=y CONFIG_VIDEO_MEDIA=y CONFIG_USB_VIDEO_CLASS=y CONFIG_V4L_USB_DRIVERS=y CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV=y
This project was originally based on a JNI implementation for UVC webcams by neuralassembly.
See the CONTRIBUTORS file for other contributors.
Copyright (c) 2011-2013 Ford Motor Company Licensed under the BSD license.