ist->hwaccel_uninit = &vaapi_decode_uninit;
ist->hwaccel_get_buffer = &vaapi_get_buffer;
ist->hwaccel_retrieve_data = &vaapi_retrieve_data;
ist->hwaccel_uninit = &vaapi_decode_uninit;
ist->hwaccel_get_buffer = &vaapi_get_buffer;
ist->hwaccel_retrieve_data = &vaapi_retrieve_data;