SurfaceViewHolder.setFixedSize(width,height) not setting size to video saved in gallery

I want to set the video aspect ratio to 1:1 capturing during android media recorder. Im using holder.setFixedSize in onSurfaceChanged method

 override fun surfaceChanged(holder: SurfaceHolder, format: Int, w: Int, h: Int) {
    // If your preview can change or rotate, take care of those events here.
    // Make sure to stop the preview before resizing or reformatting it.
    if (mHolder.surface == null) {
        // preview surface does not exist
        return
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview()
    } catch (e: Exception) {
        // ignore: tried to stop a non-existent preview
    }


    var parameters: Camera.Parameters = mCamera.getParameters()
    holder.setFixedSize(parameters.supportedPreviewSizes[0].width,parameters.supportedPreviewSizes[0].height)

    // start preview with new settings
    mCamera.apply {
        try {
            setPreviewDisplay(mHolder)
            startPreview()
        } catch (e: Exception) {
            Log.d(TAG, "Error starting camera preview: ${e.message}")
        }
    }
}

But it is only resizing the preview size. When I save the video in gallery, it is in full screen size. Also the setFixedSize method stretched the video