* TT-USB2.0 and high bitrate packet loss (DVB-C/T)
@ 2013-05-30 8:00 Hans Petter Selasky
2013-06-02 12:19 ` Hans Petter Selasky
0 siblings, 1 reply; 4+ messages in thread
From: Hans Petter Selasky @ 2013-05-30 8:00 UTC (permalink / raw)
To: linux-media, Juergen Lock
Hi there,
I need to get in concat with someone that can handle, test and review a
patch for TT-USB2.0. I've found that for certain high-bitrate streams,
the TT-USB2.0 sends more ISOCHRONOUS MPEG data than is specified in the
wMaxPacketSize fields. I have a USB analyzer capture which shows this
clearly. This of course won't be received at the USB host and packet
drops appear inside the stream. The solution is to use another alternate
setting. The technotrend chip has many of these. I've now tested using
alternate setting 7 instead of 3.
Alternate setting 7 allows transferring a maximum of 3 * 1024 bytes.
Alternate setting 3 allows transferring a maximum of 1 * 940 bytes.
--HPS
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: TT-USB2.0 and high bitrate packet loss (DVB-C/T)
2013-05-30 8:00 TT-USB2.0 and high bitrate packet loss (DVB-C/T) Hans Petter Selasky
@ 2013-06-02 12:19 ` Hans Petter Selasky
2013-06-02 21:02 ` Antti Palosaari
0 siblings, 1 reply; 4+ messages in thread
From: Hans Petter Selasky @ 2013-06-02 12:19 UTC (permalink / raw)
Cc: linux-media, Juergen Lock
On 05/30/13 10:00, Hans Petter Selasky wrote:
> Hi there,
>
> I need to get in concat with someone that can handle, test and review a
> patch for TT-USB2.0. I've found that for certain high-bitrate streams,
> the TT-USB2.0 sends more ISOCHRONOUS MPEG data than is specified in the
> wMaxPacketSize fields. I have a USB analyzer capture which shows this
> clearly. This of course won't be received at the USB host and packet
> drops appear inside the stream. The solution is to use another alternate
> setting. The technotrend chip has many of these. I've now tested using
> alternate setting 7 instead of 3.
>
> Alternate setting 7 allows transferring a maximum of 3 * 1024 bytes.
> Alternate setting 3 allows transferring a maximum of 1 * 940 bytes.
>
> --HPS
Hi,
It turns out that this device, at least the version I bought, does not
work with the XHCI at all when using multi-packet transfers, alternate
setting 7, because DATA2 PID is used when transfer is less than 1024
bytes. It should be DATA0 PID first, then 1 and 2 in the end. Probably a
firmware update can fix this, but I'm not aware about if such exists.
The PID issue was found using a USB analyzer.
Apparently this bug has gone undetected, because at least the EHCI high
speed only controller I've got silently ignores this kind of errors and
receives the data whilst the XHCI not. Conclusion:
Existing alternate setting must be used.
I think I will have to get another USB based receiver with CI slot. Any
recommendations for DVB-T ?
--HPS
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: TT-USB2.0 and high bitrate packet loss (DVB-C/T)
2013-06-02 12:19 ` Hans Petter Selasky
@ 2013-06-02 21:02 ` Antti Palosaari
2013-06-05 1:34 ` Antti Palosaari
0 siblings, 1 reply; 4+ messages in thread
From: Antti Palosaari @ 2013-06-02 21:02 UTC (permalink / raw)
To: Hans Petter Selasky
On 06/02/2013 03:19 PM, Hans Petter Selasky wrote:
> On 05/30/13 10:00, Hans Petter Selasky wrote:
>> Hi there,
>>
>> I need to get in concat with someone that can handle, test and review a
>> patch for TT-USB2.0. I've found that for certain high-bitrate streams,
>> the TT-USB2.0 sends more ISOCHRONOUS MPEG data than is specified in the
>> wMaxPacketSize fields. I have a USB analyzer capture which shows this
>> clearly. This of course won't be received at the USB host and packet
>> drops appear inside the stream. The solution is to use another alternate
>> setting. The technotrend chip has many of these. I've now tested using
>> alternate setting 7 instead of 3.
>>
>> Alternate setting 7 allows transferring a maximum of 3 * 1024 bytes.
>> Alternate setting 3 allows transferring a maximum of 1 * 940 bytes.
>>
>> --HPS
>
> Hi,
>
> It turns out that this device, at least the version I bought, does not
> work with the XHCI at all when using multi-packet transfers, alternate
> setting 7, because DATA2 PID is used when transfer is less than 1024
> bytes. It should be DATA0 PID first, then 1 and 2 in the end. Probably a
> firmware update can fix this, but I'm not aware about if such exists.
> The PID issue was found using a USB analyzer.
>
> Apparently this bug has gone undetected, because at least the EHCI high
> speed only controller I've got silently ignores this kind of errors and
> receives the data whilst the XHCI not. Conclusion:
> Existing alternate setting must be used.
>
> I think I will have to get another USB based receiver with CI slot. Any
> recommendations for DVB-T ?
There is no many alternatives available. I suspect Anysee E7 serie is
the only one. And I am not even sure if its CI works anymore. Lastly
when I tested it I didn't get scrambled channels working - but it could
be due to card entitlements were not upgraded. Anyhow, if there is bug
then it should be easy to fix.
regards
Antti
--
http://palosaari.fi/
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: TT-USB2.0 and high bitrate packet loss (DVB-C/T)
2013-06-02 21:02 ` Antti Palosaari
@ 2013-06-05 1:34 ` Antti Palosaari
0 siblings, 0 replies; 4+ messages in thread
From: Antti Palosaari @ 2013-06-05 1:34 UTC (permalink / raw)
To: Hans Petter Selasky
On 06/03/2013 12:02 AM, Antti Palosaari wrote:
> On 06/02/2013 03:19 PM, Hans Petter Selasky wrote:
>> I think I will have to get another USB based receiver with CI slot. Any
>> recommendations for DVB-T ?
>
> There is no many alternatives available. I suspect Anysee E7 serie is
> the only one. And I am not even sure if its CI works anymore. Lastly
> when I tested it I didn't get scrambled channels working - but it could
> be due to card entitlements were not upgraded. Anyhow, if there is bug
> then it should be easy to fix.
I just tested, actually first bisecting back to Kernel 3.3 and VLC2 and
it didn't work... That makes me suspect it was VLC which has gone
broken. So I tried gnutv & mplayer and surprise CI was working! Both
Anysee E7 TC and Anysee E7 T2C. Tested only DVB-C as I don't have DVB-T
subscription card. CI/CAM worked earlier for VLC somehow too.
Start tuning on terminal:
gnutv -channels /path/to/channels.conf "scrambled channel"
Start mplayer on the another terminal:
mplayer /dev/dvb/adapter0/dvr0
It is a little bit boring situation as there is no very good Gnome
Desktop TV application. Have never been...
regards
Antti
--
http://palosaari.fi/
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-06-05 1:35 UTC | newest]
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2013-05-30 8:00 TT-USB2.0 and high bitrate packet loss (DVB-C/T) Hans Petter Selasky
2013-06-02 12:19 ` Hans Petter Selasky
2013-06-02 21:02 ` Antti Palosaari
2013-06-05 1:34 ` Antti Palosaari
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