Support for 4 x vtuner - limitation

S

stick50jr

Vu+ Newbie
I have a Duo2 with internal HDD, with internal dual dvb-S2 & internal dvb-c/t tuners. I have installed BH 2.0.6c and added two usb dual dvb-t tuners. These tuners are successfully detected and operate okay. Under this set up, I have 7 tuners (3 internal cards + 4 usb (vtuners)).

The usb dual tuners are the Hauppauge Nova TD (dib0700) and the Avermedia Twinstar (AF9035).

The Duo2 information claims to be able to process/record 16 programmes simultaneously.

So I tried to record with all dvb-t tuners (from 5 x dvb-t transponders) as a partial test. The recordings were all successful BUT when I tried to play a recording from the internal HDD it failed to play back. I found that if I stopped one recording, I could then play back from the HDD. That is, it is possible to play back from HDD when 3 x vtuners are recording but not when 4 x vtuners are recording.

I don't have a satellite dish connected at the moment, so I haven't tested with the 7 tuners yet. So in summary, it is impressive to be able to use 5 x dvb-t tuners, but there is currently a limitation on simultaneous play back.

Regards
 
stick50jr said:
That is, it is possible to play back from HDD when 3 x vtuners are recording but not when 4 x vtuners are recording.
Regards
Click to expand...

Correction! (quote above is not exactly correct)

I have now been able to test more completely using combinations of satellite, terrestrial, internal and external tuners using the same 7 tuners described above.

The situation is that the Duo2 only supports 4 tuners!!! simultaneously. Even though I have successfully installed and can choose from seven tuners, I cannot use >4 tuners without having restrictions. For example when 5 tuners are in use, then playback of files is impossible. It doesn't matter what type of tuners I use, 4 tuners works fine (any combination of dvb-S2, dvb-c/t, internal, external) including 4 x vtuner.

This problem exists for BH, Vuplus, OpenPLi and Vix images. I believe this is a VU+ driver problem. They recently added support for 2 ==> 4 x vtuner for the Solo2 and Duo2. This means it is possible to have 6 tuners for a solo2, or 8 tuners for a duo2 (2 x dual internal tuners + 4 x vtuners).

VU+ need to fix their drivers to complete the extra tuners support that they have started. They advertise that the box can handle 16 x simultaneous recordings... so it would be logical to use up to 8 x tuners. The error shown in logs suggests that not enough demux instances are available.

Regards.
 
stick50jr said:
They advertise that the box can handle 16 x simultaneous recordings... so it would be logical to use up to 8 x tuners. The error shown in logs suggests that not enough demux instances are available.

Regards.
Click to expand...

No, this isn't logical. You will have 8 transport streams limited by USB 2.0 480 Mbps speed and Duo2 HW limitations.
It can handle 16 recordings = try to take in consideration 4 transport streams (DVB-S, S2, vtuner) and 4 channels for each one. Or 2 and 8 channels for each one.
 
paolino said:
No, this isn't logical. You will have 8 transport streams limited by USB 2.0 480 Mbps speed and Duo2 HW limitations.
It can handle 16 recordings = try to take in consideration 4 transport streams (DVB-S, S2, vtuner) and 4 channels for each one. Or 2 and 8 channels for each one.
Click to expand...

I understand you point and I agree that it is not compelling logic:oops:... However, the box is happy to work with 4 x vtuners through the USB... I will try this with 4 x 4 vtuner = 16 programs to see whether the USB bandwidth is a problem. The internal tuners are on a bus which hopefully is less limited than USB serial.

I'll let you know how it goes with 16 channels all through USB!
 
stick50jr said:
I'll let you know how it goes with 16 channels all through USB!
Click to expand...

Well I can successfully record 17 channels using 4 x vtuner & 1 x internal tuner. The limitation does not appear to be related to usb or I/O bandwidths. The problem is associated with there being a limited number of demux instances. We need one demux for every transponder + one for playing back recordings. To support 8 tuners (ie 8 separate transponders) we would need 9 demux instances to cover simultaneous playback. (Currently there appears to be 5 demux instances as a maximum). I think the duo2 is up to this task with the appropriate software changes!

How about it Vu... are you able to make the Duo2 into a truly super box:)
 
paolino said:
@stick50jr : Great results! Continue your tests, you know, what I was talking about ;).
Click to expand...

No further tests here, I am satisfied that there is no bandwidth issue. Vu need to upgrade their drivers to allocate additional demux's! Currently they allocate 5 demux's (good for 4 tuners + 1 file playback)... would like to see 9 demux's (good for 8 tuners + 1 file playback).

cheers
 
stick50jr said:
No further tests here, I am satisfied that there is no bandwidth issue. Vu need to upgrade their drivers to allocate additional demux's! Currently they allocate 5 demux's (good for 4 tuners + 1 file playback)... would like to see 9 demux's (good for 8 tuners + 1 file playback).

cheers
Click to expand...

Write directly to Vu+ (www.vuplus.com) about that :)
 
angelofsky1980 said:
Write directly to Vu+ (www.vuplus.com) about that :)
Click to expand...

yes, I have done this... 'bug' report to Vu+.

Perhaps other members of the forum could also write to Vu+... to emphasise the issue?

Duo2 has only demux0..demux4 (5 demux devices). Xtrend9x00 has 7 demuxes (see quote below). If Vu+ don't increase the available demuxes for their top line boxes (Solo2 and Duo2) then they are behind lesser boxes. I think it would be best to have demux0..demux8 (9 demux devices). I hope Vu+ give this some priority to allow this wonderful hardware to achieve it's potential!

root@et9x00:~# available demuxes:
/dev/dvb/adapter0/demux6
/dev/dvb/adapter0/demux5
/dev/dvb/adapter0/demux4
/dev/dvb/adapter0/demux3
/dev/dvb/adapter0/demux2
/dev/dvb/adapter0/demux1
/dev/dvb/adapter0/demux0
Click to expand...
 
stick50jr said:
yes, I have done this... 'bug' report to Vu+.

Perhaps other members of the forum could also write to Vu+... to emphasise the issue?
Click to expand...

Well Vu+ to their credit are very responsive:

VU 6/11-drivers
update driver
20131106
- Fix HDMI hotplug in standby(proc entry is also added)
- Support DVB-T2 automatic scan(uno, ultimo, duo2)
- Improve transcoding(duo2, solo2)
- Add dst_apply proc entry
- Increase demux number to 9(duo2, solo2, ultimo)
- Support blindscan in all slots(ulitmo, duo2)
Click to expand...

With 9 x demux all tuners will be able to operate simultaneously without restriction!

Thank you VU+ :yahoo:
 
So is this something VU+ have to do or is something an end user can do? I suspect the kernel will need to be built/compiled, but one can always hope.

Craig
 
bsod said:
So is this something VU+ have to do or is something an end user can do? I suspect the kernel will need to be built/compiled, but one can always hope.

Craig
Click to expand...

This is something that VU+ did in November 2013... All current images have these drivers or newer ones... So the 'limitation' referred to in the thread title no longer exists:) From this date, the Solo2, Duo2 & Ultimo fully support 8 tuners (4 internal + 4 external tuners) and the extra (9th) demux is for simultaneous playback of a recording.

So the only thing to be careful about is to get external tuners that have good driver support... as recommended elsewhere, I suggest the Hauppauge Nova-TD (dual dvb-t tuners in a single usb stick).
 
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