[linux-dvb] Re: dec2000-t success

[bruce@staff.cs.usyd.edu.au (Bruce Janson)]

    From linux-dvb-bounce@linuxtv.org Mon Apr 28 12:46:46 2003
    ...
    Date: Mon, 28 Apr 2003 12:43:13 +1000
    From: Douglas Kosovic <douglask@dstc.edu.au>
    ...
    Edward Wildgoose wrote:
    
    >>the DEC 2000-t's USB 1.1 interface will impose a 12 Mbits/s limit on
    >>its USB->PC interface.  I do not know the maximum (compressed)
    >>throughput that can be required by a 7 MHz, DVB-T transport stream
    >>(23 Mbits/s?), but I suspect that it does exceed 12 Mbits/s.
    >>If true, this would impose an unfortunate limitation on the DEC 2000-t.
    >>(USB 2.x at 480 Mbits/s would have avoided this...)
    ...
    >I am under the impression that because Australia is using QAM64 (which I
    >think means more channels per transport stream) you should find that the
    >channels have a lower max transmission than 23Mbits/s.  In the UK I think
    >the QAM64 channels are 6Mbit/s.
    ...
    I don't know about the calculations based on QAM64, but the Australian
    HDTV 1080i broadcasts are approx 4 times the resolution of SDTV 576i,
    so I would expect something like 4 times the bandwidth would be required.
     From memory, I think it's 19 Mbit/s, but I could be wrong.
    
    I wonder if the Australian DVB-T 720P HDTV broadcasts exceed the 12 Mbits/s
    USB 1.1 limit? I would imagine the bandwidth for 576p broadcasts wouldn't
    be a problem, but it would be interesting to see if the built in decoder
    can handle 576p.
    
    At least the Australian SDTV 576i channels which are 6 Mbit/s, should work.
    ...

Thanks.  Good points, but those of us who would like to grab a
whole transport stream (and then unpack it later if required)
are going to be disappointed by the Hauppauge DEC 2000-t.


-- 
Info:
To unsubscribe send a mail to ecartis@linuxtv.org with "unsubscribe linux-dvb" as subject.