DVB-T with Cuse4BSD: bad signal quality

[Jan Henrik Sylvester]

On 02/14/2010 14:44, Hans Petter Selasky wrote:
> On Sunday 14 February 2010 14:36:57 Jan Henrik Sylvester wrote:
>> After I tried video4bsd last weekend for the first time and was able to
>> make my webcam work, but not my DVB-T device. This weekend, I found
>> Cuse4BSD on your homepage replacing video4bsd.
>>
>> Now my DVB-T stick basically work. Thanks a lot for all your effort!
>>
>> I wanted to complain about the firmware path being /, but since you
>> added the '-f' switch that comes down to the rather unimportant default
>> being / and not -- for example -- /boot/modules/. Having to call webcamd
>> twice, once to load the firmware and once to actually do its job is a
>> little counter intuitive.
>>
>> My major problem at the moment is the quality of the signal. That has
>> always been dependent on the location of the antenna in my apartment,
>> but I just tried Raaf's dvbusb driver under FreeBSD 7 without having any
>> distortions and immediately booted back into FreeBSD 8: The distortions
>> are so high that it is unwatchable and after a few seconds audio and
>> video are out of sync using Raaf's typhony (Kaffeine seems a little
>> better at keeping the streams at sync even with a bad signal).
>>
>> I already checked the system load on my atom based system: 15% user, 10%
>> system, 70% idle (8% python, 8% mplayer, 4% webcamd) or 15% user, 20%
>> system, 60% idle (20% kaffeine, 7% webcamd, 5% Xorg) -- that does not
>> seem problematic. (I thought with the driver now partially in user space
>> there might be higher load than before due to context switching.)
>>
>> I am currently on FreeBSD 8.0-RELEASE with the libusb patch you
>> advertised last week on your homepage. I would not like to bring my atom
>> based system to 8-STABLE or 9-CURRENT. Would that help?
>>
>> Any idea or fix for my distortions?
>
> It might be that the Linux driver is setting up to small buffers. I have some
> patches for some of the V4L drivers, but not all. What is the VID+PID of your
> device?
>
> usbconfig -u X -a Y dump_device_desc

ugen4.4: <Digital TV Receiver Digital TV Receiver> at usbus4, cfg=0 
md=HOST spd=HIGH (480Mbps) pwr=ON

   bLength = 0x0012
   bDescriptorType = 0x0001
   bcdUSB = 0x0200
   bDeviceClass = 0x0000
   bDeviceSubClass = 0x0000
   bDeviceProtocol = 0x0000
   bMaxPacketSize0 = 0x0040
   idVendor = 0x14aa
   idProduct = 0x0226
   bcdDevice = 0x0521
   iManufacturer = 0x0001  <Digital TV Receiver>
   iProduct = 0x0002  <Digital TV Receiver>
   iSerialNumber = 0x0003  <20060503>
   bNumConfigurations = 0x0001

(I will not be able to answer anymore for a few hours.)

Cheers,
Jan Henrik