Black ImageAnalysis Use Case (VideoCapture + Preview fine)

[Aubrey Haskett]

Hi there CameraX! I see a number of posts in here about black preview screens, but they are old and I see some of those issues were resolved, so I'll post my similar but new problem below:

I am using Preview, VideoCapture, and ImageAnalysis use cases.

• When using all 3, my Preview and recording resulting from VideoCapture look great, but my ImageAnalysis yields a black screen. 
• I've noticed that, after I pinch to zoom in (so I call camera?.cameraControl?.setZoomRatio(intendedZoom)), the problem is resolved and ImageAnalysis output looks great. 
• If I use Preview and VideoCapture only or Preview and ImageAnalysis only, those always work as well, without the pinch to zoom trick. 
• I originally thought this was a resolution mismatch problem - maybe my device didn't have the right hardware level, but the fact that applying zoom fixes this is odd. 

Any ideas? Here's some info on my config:

• I am using a Pixel 8 Pro with CameraX library 1.3.0. 
• I have no use case binding errors and no quality, resolution, or cameraSelector builder errors.
• I set the Preview and ImageAnalysis use cases' resolution like so (resolution parameter is my own variable, could be 480p or 720p: 
  • val resolutionSelector = ResolutionSelector.Builder().setResolutionStrategy(ResolutionStrategy(Size(resolution.width, resolution.height), ResolutionStrategy.FALLBACK_RULE_CLOSEST_HIGHER_THEN_LOWER)).setAspectRatioStrategy(AspectRatioStrategy(resolution.width / resolution.height, AspectRatioStrategy.FALLBACK_RULE_AUTO)).build()

• I set the VideoCapture quality like so: 
  • val selector = QualitySelector.from(Quality.FHD,FallbackStrategy.higherQualityOrLowerThan(Quality.SD))

• I am using the CameraSelector.DEFAULT_BACK_CAMERA
• My Preview use case does not have an implementation mode strategy set, so it is defaulting to PERFORMANCE (changing to COMPATIBLE doesn't seem to fix issue)
• My Image Analysis use case is set to use ROTATION_0 and back pressure strategy ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST

Many thanks for continuing to be active in this channel. You are always a big help, whether it be replies to me or others that I can read through. 

[Charcoal Chen]

Thanks for reporting the issue and providing the detailed info.

I have created  https://issuetracker.google.com/issues/376774901 to track this issue. I'll update to the issue after clarifying the root cause.