[linux-dvb] Need Help with PCTV 452e (USB DVB-S2 device with STB0899)

Manu Abraham abraham.manu at gmail.com
Fri Feb 29 23:52:47 CET 2008


Dominik Kuhlen wrote:
> On Friday 22 February 2008, Dominik Kuhlen wrote:
>> Hi,
>>
>> -----snip----
>>> Great, that was the trick, now scanning and szap work fine.
>>>
>>> Thanks for that hint!
>> You're welcome.
>>
>> BTW: do you receive broken streams  (symbol rate 22000 or 27500)?
>> Currently I get a loss of about 1 TS packet every second or even more (with both symbol rates).
>> And there is exactly one TS packet missing (I diffed a TS hexdump).
>> If it were the USB controller that drops packets it would be a loss of 5 consecutive TS packets. (940 bytes iso frame size)
> 
> I have to correct that statement (I didn't record the whole TS): 
> The loss is exactly one USB frame (5 consecutive TS packets in this case)
> which happens about every 1000 TS packets (200 USB frames)


Is it really isochronous transfer that the device really uses in it's
default mode ? I guess many vendors prefer bulk transfers for the
default transfer mode ?

Regards,
Manu



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