preview_page.dart

Stack(
  children: [
    AspectRatio(
      aspectRatio: 16 / 9,
      child: Container(
        color: Colors.black,
        width: double.maxFinite,
        child: Center(
          child: CircularProgressIndicator(
            valueColor: AlwaysStoppedAnimation<Color>(
              CustomColors.muxPink,
            ),
            strokeWidth: 2,
          ),
        ),
      ),
    ),
    _controller.value.initialized
        ? AspectRatio(
            aspectRatio: _controller.value.aspectRatio,
            child: VideoPlayer(_controller),
          )
        : AspectRatio(
            aspectRatio: 16 / 9,
            child: Container(
              color: Colors.black,
              width: double.maxFinite,
              child: Center(
                child: CircularProgressIndicator(
                  valueColor: AlwaysStoppedAnimation<Color>(
                    CustomColors.muxPink,
                  ),
                  strokeWidth: 2,
                ),
              ),
            ),
          ),
  ],
),