ArVideoFragment.kt

requireContext().assets.openFd(augmentedImage.name)
    .use { descriptor ->

        val metadataRetriever = MediaMetadataRetriever()
        metadataRetriever.setDataSource(
            descriptor.fileDescriptor,
            descriptor.startOffset,
            descriptor.length
        )

        val videoWidth = metadataRetriever.extractMetadata(METADATA_KEY_VIDEO_WIDTH).toFloatOrNull() ?: 0f
        val videoHeight = metadataRetriever.extractMetadata(METADATA_KEY_VIDEO_HEIGHT).toFloatOrNull() ?: 0f
        val videoRotation = metadataRetriever.extractMetadata(METADATA_KEY_VIDEO_ROTATION).toFloatOrNull() ?: 0f

        // Account for video rotation, so that scale logic math works properly
        val imageSize = RectF(0f, 0f, augmentedImage.extentX, augmentedImage.extentZ)
            .transform(rotationMatrix(videoRotation))

        val videoScaleType = VideoScaleType.CenterCrop

        videoAnchorNode.setVideoProperties(
            videoWidth = videoWidth, videoHeight = videoHeight, videoRotation = videoRotation,
            imageWidth = imageSize.width(), imageHeight = imageSize.height(),
            videoScaleType = videoScaleType
        )
          
        mediaPlayer.reset()
        mediaPlayer.setDataSource(descriptor)
    }.also {
        mediaPlayer.prepare()
        mediaPlayer.start()
    }