Re: Noisy video with Avermedia AVerTV Digi Volar X HD (AF9015) and mythbuntu 9.04

[Antti Palosaari <crope@iki.fi>]

On 08/26/2009 01:01 AM, Devin Heitmueller wrote:
> On Tue, Aug 25, 2009 at 5:50 PM, Antti Palosaari<crope@iki.fi>  wrote:
>> USB2.0 BULK stream .buffersize is currently 512 and your patch increases it
>> to the 65424. I don't know how this value should be determined. I have set
>> it as small as it is working and usually it is 512 used almost every driver.
>> 511 will not work (if not USB1.1 configured to the endpoints).
>>
>> ****
>>
>> Could someone point out how correct BULK buffersize should be determined? I
>> have thought that many many times...
>
> Usually I do a sniffusb capture of the Windows driver and use whatever
> they are using.

Should try that if better trick is not known.

>> ****
>>
>> Also one other question; if demod is powered off and some IOCTL is coming -
>> like FE_GET_FRONTEND - how that should be handled? v4l-dvb -framework does
>> not look whether or not demod is sleeping and forwards that query to the
>> demod which cannot answer it.
>
> In other demods, whenever the set_frontend call comes in the driver
> check to see if the device is asleep and wakes it up on demand.  On
> some demods, you can query a register to get the power state.  In
> other cases you have to manually keep track of whether you previously
> put the demod to sleep using the demod's state structure.

If demod (and tuner) is powered off by bridge (.power_ctrl) that's not 
possible. Is there way to call bridge .power_ctrl to wake up demod and 
tuner? I added param for demdod state to track sleep/wake state and 
return 0 in sleep case. But that does not sounds good solution...

Thank you for fast answer.

regards
Antti
-- 
http://palosaari.fi/