agentsclimarketplace

Android emulator mask testing

Skill simiancraft/simiancraft-skills/skills/android-emulator-mask-testing

Public Claude Code skills and agents from simiancraft. Marketplace-installable.

Install
npx -y skills add simiancraft/simiancraft-skills --skill android-emulator-mask-testing

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

One thing to look at

  • 6 stars6 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

What its author says it does

Copied from the file, not written here

Specialization of android-emulator-harness for CAMERA / segmentation testing: get a real PERSON in front of the emulator camera so MediaPipe / ML Kit selfie segmentation produces an actual mask, then verify background-replacement / blur / shader effects and tune mask threshold by vision. Use when the task is "test the mask", "verify segmentation", "tune mask threshold", "check a camera/background effect on Android", or any time an app must SEE a human through the emulator camera without a physical device. Read android-emulator-harness FIRST for bring-up, drive, and assert; this skill only overrides the camera-specific pieces. Validated on Linux/WSL with a 32-bit x86 emulator image and MediaPipe/ML Kit segmentation.

SKILL.md

6.4 KB, as published. Nobody here has run it

Camera / Mask Testing: specialization of android-emulator-harness

Read android-emulator-harness first. That base covers KVM, AVD creation, headless boot, app install/launch, Maestro driving, logcat/screenshot assertion, and teardown. This skill changes only what's needed to put a segmentable human in the camera and run GPU segmentation. Everything else (drive with Maestro, assert on logcat + screenshot) is identical to the base.

This skill ships one fixture: fixtures/person-framed.png, a full-body subject pre-positioned for the emulator's camera-feed crop (see override 3). Feed it directly, or swap in your own subject framed the same way.

The three camera-specific overrides (each cost real debugging time)

  1. Use a 32-bit x86 system image, NOT the base's x86_64. MediaPipe Tasks Vision ships libmediapipe_tasks_vision_jni.so for arm64-v8a, armeabi-v7a, and x86, not x86_64. On x86_64 it fails with UnsatisfiedLinkError and segmentation silently falls through to the raw frame. API 30 is the highest 32-bit x86 google_apis image. Verify in the APK: unzip -l app.apk | grep mediapipe (expect a lib/x86/… entry).

    yes | "$SDKMGR" "system-images;android-30;google_apis;x86"
echo no | "$AVDMGR" create avd -n harness_x86 -k "system-images;android-30;google_apis;x86" -d pixel_3 --force

  2. Boot with -gpu swangle_indirect, NOT the base's swiftshader_indirect. MediaPipe runs through TFLite's GPU delegate, which needs GLES 3.1 compute shaders. Raw SwiftShader is only GLES 3.0 → [GL_INVALID_ENUM] glCreateShader in TensorsToSegmentationCalculator. swangle (ANGLE over SwiftShader-Vulkan) exposes GLES 3.1. Confirm after boot; this is the make-or-break check:

    adb shell dumpsys SurfaceFlinger | grep -m1 "GLES:"   # MUST say "OpenGL ES 3.1 ... ANGLE"

  3. Feed the framed subject straight into the camera (-camera-back imagefile:). A recent emulator presents a still image as the back camera. Confirm support first ("$EMU" -help-camera-back lists imagefile: / videofile:); upgrade if missing (yes | "$SDKMGR" emulator). Feed the pre-framed image, not a bare cutout: the imagefile-to-sensor path does not present the image 1:1; it crops and shifts, so a subject centered in the source lands off to the right with the head clipped. fixtures/person-framed.png is pre-compensated. The framing that lands the subject centered and fully in frame:

    • Frame: 9:16 portrait (e.g. 1080 x 1920).
    • Subject height: ~0.42 of the frame height (full body, not a close-up).
    • Subject center: x = 0.25 W, y = 0.58 H. The left-quarter x is deliberate; it cancels the sensor path's rightward shift so the subject reads centered on screen.
    • Background: opaque and contrasting (a light neutral gray works); segmentation needs a clean figure/ground split, and the background is what gets replaced.

    These offsets are emulator/AVD/version specific. Calibrate once: feed the image, select no effect to see the raw camera preview, screenshot it, and nudge the subject's x-center until it reads centered before trusting a run. To re-frame for a different crop, recompose from your own transparent subject using the offsets above.

Full launch (base boot + the three overrides)

sg kvm -c "nohup $EMU -avd harness_x86 \
  -no-window -no-audio -no-boot-anim -no-snapshot \
  -gpu swangle_indirect \
  -camera-back imagefile:$PWD/fixtures/person-framed.png \
  -accel on -port 5554 > /tmp/emulator.log 2>&1 &"
# then base boot-wait, then dumpsys SurfaceFlinger GLES check MUST be 3.1/ANGLE

-no-snapshot forces a clean boot so the camera feed takes effect. Pass an absolute path to the imagefile; the example uses $PWD assuming you launch from the skill dir.

Asserting the mask (beyond the base's logcat gate)

Add these to the base's HARD logcat gate (all must be ABSENT): UnsatisfiedLink, GL_INVALID_ENUM, glCreateShader, CalculatorGraph::Run() failed.

Then drive an effect (Maestro: tapOn: "Dark Office") and Read the screenshot. A working mask shows the person kept and the background replaced. Failure modes: unchanged room (segmentation fell through) or person gone (empty mask). For threshold tuning, iterate the app's maskThreshold/hardness controls and re-Read.

What this adds to the base's scope

  • CAN now also validate: mask SHAPE + compositing (person carved, bg swapped).
  • Still CANNOT: temporal mask quality (flicker/edge stability) from a STATIC image; that needs motion. Use -camera-back videofile:<abs>/subject.mp4 for a full-frame moving subject when you need to test edge stability over time.

Older emulators without imagefile:

Builds whose -help-camera-back lacks imagefile: can still put a subject in view via the virtualscene wall poster. The headless camera pose is not settable (telnet sensor set is ignored; only the gRPC physical model moves it), so move the poster into the camera's fixed view (camera sits near origin looking down −Z): feed your own transparent full-body cutout as -camera-back virtualscene -virtualscene-poster wall=<subject.png> and set geometry in $SDK/emulator/resources/Toren1BD.posters (back it up first; the wall anchor is guaranteed to render). Upgrading the emulator to get imagefile: is simpler; prefer that.

Teardown

adb -s emulator-5554 emu kill
# only if you used the virtualscene fallback and edited resources:
# cp "$SDK/emulator/resources/Toren1BD.posters.bak" "$SDK/emulator/resources/Toren1BD.posters" 2>/dev/null || true

Keep looking

Skills are one crate of 328,083. Ordering is by how many stacks a row turns up in, so the top of any crate is what has actually been picked rather than what has the most stars.