Coding Spirit

AWS doesn’t provide official AWS CLI V2 binary release for Raspberry Pi. To install V2 on Raspberry Pi, we have to install it from source:

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git clone https://github.com/aws/aws-cli.git
cd aws-cli && git checkout v2
sudo pip3 install -r requirements.txt
sudo pip3 install . --prefix /usr/local

GNU linker provides an --wrap option which can help developer replace symbols easily.

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By creating 2 targets and set same OUTPUT_NAME for both targets:

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add_library(v4l2capturer-shared SHARED ${V4L2CAPTURER_SRC})
target_include_directories(v4l2capturer-shared PRIVATE ${LIBV4L2_INCLUDE_DIRS})
target_include_directories(v4l2capturer-shared PUBLIC ${V4L2CAPTURER_INC})
set_target_properties(v4l2capturer-shared PROPERTIES OUTPUT_NAME v4l2capturer)
target_link_libraries(v4l2capturer-shared PRIVATE ${LIBV4L2_LIBRARIES})

add_library(v4l2capturer-static STATIC ${V4L2CAPTURER_SRC})
target_include_directories(v4l2capturer-static PRIVATE ${LIBV4L2_INCLUDE_DIRS})
target_include_directories(v4l2capturer-static PUBLIC ${V4L2CAPTURER_INC})
set_target_properties(v4l2capturer-static PROPERTIES OUTPUT_NAME v4l2capturer)
target_link_libraries(v4l2capturer-static PRIVATE ${LIBV4L2_LIBRARIES})

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Some RPi models(like Pi Zero and Pi 4) have OTG capabilities which allowed us to use them as USB gadgets. Since ADB can be connected via USB FFS, we are able to bring up adbd on RPi and connect to it via USB.

User might expiring SDP failure on non-Qualcomm/SAMSUNG chip Android devices when received SDP from another peer that only support H.264. This was caused by a limitation of Android WebRTC SDK that it will check H.264 capabilities via a chip whitelist, which only has Qualcomm and Exynos listed. To make it available for other Android devices, we need to modify and recompile WebRTC Android SDK.

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To generate ECDSA Digital Signature: ECDSA: Generate ECDSA Key/Certificate/Signature By openssl

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