Not much later since the previous element, ahcsrc, has been merged into 'gst-plugins-bad', Android N announced their public native level APIs. This news brought me another R&D opportunity to implement same featured, but more stable and little bit faster element to handle Camera Devices on Android.
I named the new element as 'ahc2src' because the previous one is just 'ahcsrc' and the fundamental API is Android Camera 2 NDK API. That means JNI is no longer required to access Camera devices. To understand why 'ahc2src' is better, here's comparison chart.
ahcsrc
|
ahc2src
|
|
| Supported Android version |
> Lollipop (android-19)
|
> Nougat (android-24)
|
| API |
Camera API
|
Camera 2 NDK API
|
| Device control |
Java API through JNI
|
Native
|
| Supported Image Format |
YV12, YUY2, NV16, NV21, RGB16
|
NV12 (YUV_420_888)
|
| Memory Copy |
Java to GstBuffer
|
None (AImageReader inside)
|
Regarding memory copy, I'm not sure whether it doesn't perform inside of Android. However, ahc2src itself just passes image pointers to source pad and manage the reference counts.
How to get this new element?
Until merged and released gstreamer images which are built for Android Nougat, my personal repository will be continuously maintained to provide 'ahc2src' element. If you want to build from scratch, it might be annoying because of some issues which come from Android NDK.
See the details in the below links;
Build from Cerbero
In my personal repository, the patches are ready to build. It will fetch 'gst-plugins-bad' from here.
Note that 'wip/ahc2' branch is potentially or frequently overwritten by forced push.
Then, the generated SDK image should be extracted to a proper path. (e.g /Users/justin/Library/Android/gstreamer/devel/arm64)
Gstreamer Android Camera Example Application
From the point of Android application view, there's not much different from when using 'ahcsrc'. In theory, it might be enough to replace 'ahcsrc' with 'ahc2src'.
Then, you should modify 'gradle.properties' to set a proper gstreamer SDK path. (e.g, gstAndroidRoot=/Users/justin/Library/Android/gstreamer/devel)
If there's no error, the example application will be installed successfully.
Enjoy your Gstreamer with Android Camera 2 source!
How to get this new element?
Until merged and released gstreamer images which are built for Android Nougat, my personal repository will be continuously maintained to provide 'ahc2src' element. If you want to build from scratch, it might be annoying because of some issues which come from Android NDK.
See the details in the below links;
- BIONIC's dlopen and dlsym (glib patch, gstreamer issue)
- Cebero build failure
- ahc2src working history
Build from Cerbero
In my personal repository, the patches are ready to build. It will fetch 'gst-plugins-bad' from here.
$ git clone https://gitlab.collabora.com/joykim/cerbero.git $ git checkout wip/ahc2
Note that 'wip/ahc2' branch is potentially or frequently overwritten by forced push.
$ ./cebero-uninstalled -c config/cross-android-nougat-arm64.cbc bootstrap $ ./cebero-uninstalled -c config/cross-android-nougat-arm64.cbc package gstreamer-1.0
Then, the generated SDK image should be extracted to a proper path. (e.g /Users/justin/Library/Android/gstreamer/devel/arm64)
Gstreamer Android Camera Example Application
From the point of Android application view, there's not much different from when using 'ahcsrc'. In theory, it might be enough to replace 'ahcsrc' with 'ahc2src'.
$ git clone https://gitlab.collabora.com/joykim/gst-android-camera.git $ git checkout wip/ahc2
Then, you should modify 'gradle.properties' to set a proper gstreamer SDK path. (e.g, gstAndroidRoot=/Users/justin/Library/Android/gstreamer/devel)
$ gradle installDebug
If there's no error, the example application will be installed successfully.
Enjoy your Gstreamer with Android Camera 2 source!
