libjpeg-turbo for Unity. libjpeg-turbo is a faster image codec.
While Unity's ImageConversion.EncodeArrayToJPG is fast enough for single use, for every-frame use or on older PCs/Mobile platforms the difference is huge.
Currently supports Android armeabi-v7a / arm64-v8a and Windows x86 / x64. At least that was my use case. If you want more platforms, you can build your own libjpeg-turbo and still use the same importer/wrapper here.
Otherwise, simply download Plugins.zip file from releases tab and put it under your Assets folder.
Capture settings:
- Streaming Camera RenderTexture resolution: 1440x810
- Target FPS for Streaming Camera: 30
- Encode Quality: 75
Numbers in the first row are gathered with StopWatch, and in milliseconds.
Numbers in the second row are gathered with Time.realtimeSinceStartupAsDouble for more precision.
All values are aggregated and averaged on a fixed sized queue (250 frame).
LibJpegTurboUnityExample.mp4
Even though on Windows x64 libjpeg-turbo is x1.25 faster, if you run it at 60 FPS it makes a difference and the room for more things is always welcome. Though it still can be considered as a micro optimization.
On Android though, the difference is x5, so it's a pretty clear choice.
Unity project is under UnityProject folder, and is a simple representation/demonstration of the usage. It also shows the folder structure and usage (i.e. create/import/dispose) of the library. It's using AsyncGPUReadback to capture the gameview and display it on the preview screens on top of the screen.
You can simply get the Plugins.zip from releases and put it on your project if you don't want to deal with it, but still, you may need the example.
Library project is under CsProject folder and is used to create a dll file to use the libjpeg-turbo libraries. Basically it includes an importer and encoder functionalities.
You can simply get the .cs files from this project and put it under your Unity project to use it. You don't have to use the .dll file, but it's less clutter, and compatible with the IL2CPP build.
If you need to build the libraries yourself for any reason, or if an updated version of the libjpeg-turbo was released and you want to update, you need Android NDK, Visual Studio, CMake and make to be able to build the libraries yourself.
Go and get the source for libjpeg-turbo first.
Set the necessary variables to use the paths.
NDK_PATH=<your Android NDK root path>
TOOLCHAIN=$NDK_PATH/toolchains/llvm/prebuilt/windows-x86_64/
ANDROID_VERSION=29
Depending on your use case, you may change the Android version
cmake -G "Unix Makefiles" -DANDROID_ABI=armeabi-v7a -DANDROID_ARM_MODE=arm -DANDROID_PLATFORM=android-${ANDROID_VERSION} -DANDROID_TOOLCHAIN=${TOOLCHAIN} -DCMAKE_ASM_FLAGS="--target=arm-linux-androideabi${ANDROID_VERSION}" -DCMAKE_TOOLCHAIN_FILE=${NDK_PATH}/build/cmake/android.toolchain.cmake -DCMAKE_MAKE_PROGRAM:FILEPATH=<your_make_binary_path> <your_libjpeg-turbo_source_folder>
Then simply
make
cmake -G "Unix Makefiles" -DANDROID_ABI=arm64-v8a -DANDROID_ARM_MODE=arm -DANDROID_PLATFORM=android-${ANDROID_VERSION} -DANDROID_TOOLCHAIN=${TOOLCHAIN} -DCMAKE_ASM_FLAGS="--target=aarch64-linux-android${ANDROID_VERSION}" -DCMAKE_TOOLCHAIN_FILE=${NDK_PATH}/build/cmake/android.toolchain.cmake -DCMAKE_MAKE_PROGRAM:FILEPATH=<your_make_binary_path> <your_libjpeg-turbo_source_folder>
Then simply
make
cmake -G "Visual Studio 17 2022" -A Win32 ../../../libjpeg-turbo-3.0.2/
cmake -G "Visual Studio 17 2022" -A x64 ../../../libjpeg-turbo-3.0.2/
Then use the generated Visual Studio project files to build your own .dll file of the libjpeg-turbo. You can also use a different version of Visual Studio if you want, just go check the CMake documentation for it.