chadversary's android-ndk-rutabagas

In this demo you will find not gems, but mere rutabagas.

This repo currently contains only one demo, but I have more demos waiting to be pushed.

This buggy demo decodes a video file with the AMedia APIs; imports the AHardwareBuffer from the decoded video frame into Vulkan using VK_ANDROID_external_memory_android_hardware_buffer; creates a VkSamplerYcbcrConversion to convert the AHardwareBuffer's YCbCr colorspace into RGB; copies the AHardwareBuffer into the VkSurface with a small shader and the VkSamplerYcbcrConversion.

Bugs

• git grep -E 'FIXME|WORKAROUND|FINISHME'
• The demo attempts to smoothly play the video, but instead it presents just a few choppy frames and then unexpectedly stops. Patches welcome.

Build Dependencies

The Android NDK, of course.

glslc: CMake must be able to find the 'glslc' executable. The easiest way to satisfy CMake is to put 'glslc' in your shell's $PATH.

To build and install glslc:
    > git clone -b known-good https://github.com/google/shaderc ~/shaderc
    > cd ~/shaderc
    > ./update_shaderc_sources.py
    > cd src
    > cmake -G Ninja
    > ninja
    > sudo ninja install

How to Build and Install

pkg='com.example.media_to_vk_ahb' ./gradlew buildDebug adb connect $REMOTE ./gradlew installDebug adb shell pm grant "$pkg" android.permission.READ_EXTERNAL_STORAGE

How to Run

adb push /your/favorite/video.ext /sdcard/Download/ adb logcat -c adb shell am start -n "$pkg/android.app.NativeActivity" \ -e mediaSrc /sdcard/Download/video.ext adb logcat -v color

If the activity dies early with a log message like "Vulkan does not have device extension VK_EXT_queue_family_foreign" then edit the #ifdef found by git grep 'WORKAROUND: VK_EXT_queue_family_foreign'.

The activity accepts the following optional key/value pairs:

-e useVkExternalFormat (auto|never|always) # default=auto
    Control if the AHardwareBuffer is imported with
    VkExternalFormatANDROID. If useVkExternalFormat=never but the
    AHardwareBuffer requires an external format, then the activity will
    abort with a diagnostic log message.

-e useVkValidation (true|false) # default=true
    Enable the Vulkan validation layers.