microg/GmsCore · error · IOException

Could not find suitable preview size.

Error message

Could not find suitable preview size.

What it means

Camera negotiation failure in CameraSource.pickCameraSize: none of the camera's supported preview/picture size candidates could be matched to the requested dimensions, so no preview size can be selected on this device.

Source

Thrown at play-services-vision-common/src/main/java/com/google/android/gms/vision/CameraSource.java:405

        if (sizeCandidates.size() == 0) {
            for (Camera.Size previewSize : camera.getParameters().getSupportedPreviewSizes()) {
                sizeCandidates.add(new SizePair(previewSize, null));
            }
        }

        SizePair sizePair = null;
        int selectedSizeOffset = Integer.MAX_VALUE;
        int sizeOffset;
        for (SizePair candidate : sizeCandidates) {
            Size candidatePreviewSize = candidate.preview;
            sizeOffset = Math.abs(candidatePreviewSize.getWidth() - requestedWidth) + Math.abs(candidatePreviewSize.getHeight() - requestedHeight);
            if (sizeOffset < selectedSizeOffset) {
                sizePair = candidate;
                selectedSizeOffset = sizeOffset;
            }
        }

        if (sizePair == null) throw new IOException("Could not find suitable preview size.");
        return sizePair;
    }

    private static class SizePair {
        Size preview;
        Size picture;

        public SizePair(Camera.Size preview, Camera.Size picture) {
            this.preview = new Size(preview.width, preview.height);
            if (picture != null) {
                this.picture = new Size(picture.width, picture.height);
            }
        }
    }

    private class DetectorRunner implements Runnable {
        private final Object lock = new Object();
        private long startElapsedRealtime = SystemClock.elapsedRealtime();

View on GitHub (pinned to 157c9d86ac)

Solutions

1. Request a more common preview resolution (e.g. 640x480) supported by the device
2. Pick the closest match manually from getSupportedPreviewSizes()
3. Catch the exception and fall back to a default size or disable camera detection

When it happens

Trigger: Thrown at play-services-vision-common/src/main/java/com/google/android/gms/vision/CameraSource.java:405 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microg/GmsCore@157c9d86ac (2026-09-06). Data as JSON: /api/errors/acfff5c90966f619. Report an issue: GitHub.