Modern IPTV services are comprised of multiple comprehensive service elements in the entire content delivery chain to maximise the efficiency in networking. Audio-visual content may experience various types of impairments during content ingest, processing, distribution and reception.While some impairments do not cause noticeable distortions to the delivered content, many others such as the network transmission loss can be highly detrimental to the user experience in content consumption. In order to optimise service quality and to provide a benchmarking platform to evaluate the designs for future audio-visual content distribution system, a quality evaluation framework is essential. We introduce such an evaluation framework to assess video service with respect of user perception, while supporting service diagnosis to identify root-causes of any detected quality degradation. Compared with existing QoE frameworks, our solution offers an advanced but practical design for the real-time analysis of IPTV services in multiple service layers.