|There has been a
lot of discussion of distribution of 19.39Mbps ATSC bitstreams by
networks. Unfortunately, these highly
compressed bitstreams cant survive decoding and processing and then
re-coding for transmission to the home without severe degradation to the
quality of the delivered signal. If
the program has 5.1 channel audio, even minor level shifts in the discrete
channels will severely affect the AC-3 quality.
are some applications where 19.39 systems will be employed, they are severely
limited in number and capability.
nature of bit-splicing techniques for splicing the ATSC bitstream and the
inherent limitations of not being able to control content, brand the signal,
or easily meet EAS and weather information needs make the usefulness of bit
splicing and 19.39 systems extremely limited.
|The next three
slides show some possible scenarios.