media3/demos/transformer

Transformer demo

This app demonstrates how to use the Transformer API to modify videos, for example by removing audio or video.

See the demos README for instructions on how to build and run this demo.

MediaPipe frame processing demo

Building the demo app with MediaPipe integration enabled requires some extra manual steps.

1. Follow the instructions to install MediaPipe.

2. Copy the Transformer demo's build configuration and MediaPipe graph text protocol buffer under the MediaPipe source tree. This makes it easy to build an AAR with bazel by reusing MediaPipe's workspace.

   cd "<path to MediaPipe checkout>"
   MEDIAPIPE_ROOT="$(pwd)"
   MEDIAPIPE_TRANSFORMER_ROOT="${MEDIAPIPE_ROOT}/mediapipe/java/com/google/mediapipe/transformer"
   cd "<path to the transformer demo (containing this readme)>"
   TRANSFORMER_DEMO_ROOT="$(pwd)"
   mkdir -p "${MEDIAPIPE_TRANSFORMER_ROOT}"
   mkdir -p "${TRANSFORMER_DEMO_ROOT}/libs"
   cp ${TRANSFORMER_DEMO_ROOT}/BUILD.bazel ${MEDIAPIPE_TRANSFORMER_ROOT}/BUILD
   cp ${TRANSFORMER_DEMO_ROOT}/src/withMediaPipe/assets/edge_detector_mediapipe_graph.pbtxt \
     ${MEDIAPIPE_TRANSFORMER_ROOT}
   

3. Build the AAR and the binary proto for the demo's MediaPipe graph, then copy them to Transformer.

   cd ${MEDIAPIPE_ROOT}
   bazel build -c opt --strip=ALWAYS \
     --host_crosstool_top=@bazel_tools//tools/cpp:toolchain \
     --fat_apk_cpu=arm64-v8a,armeabi-v7a \
     --legacy_whole_archive=0 \
     --features=-legacy_whole_archive \
     --copt=-fvisibility=hidden \
     --copt=-ffunction-sections \
     --copt=-fdata-sections \
     --copt=-fstack-protector \
     --copt=-Oz \
     --copt=-fomit-frame-pointer \
     --copt=-DABSL_MIN_LOG_LEVEL=2 \
     --linkopt=-Wl,--gc-sections,--strip-all \
     mediapipe/java/com/google/mediapipe/transformer:edge_detector_mediapipe_aar.aar
   cp bazel-bin/mediapipe/java/com/google/mediapipe/transformer/edge_detector_mediapipe_aar.aar \
     ${TRANSFORMER_DEMO_ROOT}/libs
   bazel build mediapipe/java/com/google/mediapipe/transformer:edge_detector_binary_graph
   cp bazel-bin/mediapipe/java/com/google/mediapipe/transformer/edge_detector_mediapipe_graph.binarypb \
     ${TRANSFORMER_DEMO_ROOT}/src/withMediaPipe/assets
   

4. In Android Studio, gradle sync and select the withMediaPipe build variant (this will only appear if the AAR is present), then build and run the demo app and select a MediaPipe-based effect.