| Workshop on Standardization in E-Health |
Geneva, 23-25 May 2003
Abstract
MPEG-4 video transmission for ambulatory application
We explain a method of MPEG-4 video transmission for ambulatory application. In this presentation,
we suppose that the video image of the patient and of the medical equipment in the ambulance is
transmitted to the hospital via wireless communications such as satellite communications, wireless
LAN and mobile phone. The video image in the ambulance is inputted to computers as NTSC (or may be PAL)
signal and digitized, encoded in the computers and transmitted to wireless transmission equipment via
Ethernet. At the hospital, the received packets in wireless transmission equipment are inputted to computers
via Ethernet and reconstructed to the bitstream and decoded to the display. For stereoscopic vision, the
output of 2PCs should be superimposed using projectors with polarized filters. A software codec which conforms
to the MPEG-4 Visual simple profile is used. With a CPU of Pentium 3 1GHz, it is possible that the video of QVGA
resolution and 15 fps can be encoded and decoded in real-time. UDP/IP is used as the underlying protocol of RTP.
Using RTP, loss of packets, disorder and fluctuation of arrived packets can be detected. Encoded with the MPEG-4
format, error concealment function works, but loss concealment cannot be done. So, a packet loss concealment
algorithm which utilizes the spatial similarity inside the picture was developed. With the video transmission
experiment which uses the experimental vehicle, we plan to survey the occurrence of data error and loss and to
develop a more robust video transmission method using error correction codes in the near future.
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