• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint

15.3. Error-Resilience Test

Universal access is one of the most important MPEG-4 functionality (see Chapter 1); this functionality refers to the provision of acceptable quality even for error-prone channels such as mobile environments (burst-error environment) or the Internet (packet-loss environment). MPEG-4 video error-resilience tools [MPEG4-2] are the solution for this problem. The error-resilience test performed in June 1998 had the objective of verifying the MPEG-4 capabilities in terms of error resilience under realistic error-prone conditions [N2165, N2604]. It is expected that the error-resilient MPEG-4 video profiles[7] will be used for existing and future wireless and mobile networks (such as GSM, DECT, GPRS, and IMT-2000), with bit rates ranging from 24 kbit/s to 2 Mbit/s. In this context, possible applications are personal real-time conversational services (e.g., videotelephony), video retrieval (e.g., video on demand), surveillance, and remote monitoring. It should be noted that the transmission delay and the total bit rate are important for these applications, especially in mobile environments; video error resilience can help in this context by allowing the decoder to gracefully recover from residual bit errors in the transmission.

[7] All MPEG-4 video (natural visual) object types with the exception of the Studio object types include error-resilience tools.

15.3.1. Test Conditions

To perform the error-resilience test, the wireless system model shown in Figure 15.9 was used. This model is a typical example of a wireless multimedia communication system and consists of the following four layers:


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint