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Jay Barberio

Time share channel support

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Jay Barberio

On the UK DTT system, many channels 'time-share' bandwidth, by switching the same video and audio between each other.

 

STB are able to scan and locate these channels, because they still provide a SID while not 'transmitting' and provide only an MHEG stream. The STB scans and stores these as Data only channels, but updates pid information from the channel every time the channel is changed to it, and at periods while the channel (or it's MUX depending on implementation) is selected. (This channels also have EPG data supplied by one of the various EPG suppliers)

 

Most DVB Software, including DVBViewer give no support for this. Either storing the channel as Data only but not making update checks, or discarding the channel as DVBViewer does. This requires the User to re-scan manually while the channels are transmitting.

 

It would be more useful to us in the UK if DVBViewer mimicked STB behaviour, by showing Data-Only channels, and periodically updating their information when the user selects them. (Or it's MUX is tuned)

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Derrick

How does a user know, when a certain service with a given program number is active or not ? With German paytv provider Premiere the so called option channels are linked via the epg (EIT) to a portal and can be selected accordingly by the DVBViewer. Another, different example relates to channels that split into regional programmes at certain times. This is also covered by the DVBViewer.

 

Certain interactive services from the bbc and other british providers need the implementation of OpenTV. Afaik, you won't find opentv on any stb other than from bskyb.

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Dvb-tv

For the UK BBC interactive channels what do you require, just the key to get the data. Do you need a service list for these streams, to enable implentation into DVBViewer.

 

I have looked around the DVBViewer folders. I cannot see a txt type file i can manualy enter the needed values into. All i found was the EPG file that listed all that had been recieved, but no setup EPG file. A txt type ascii file would help so can manualy adjust for any future changes or new interactive services.

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Guest Lars_MQ
A txt type ascii file would help so can manualy adjust for any future changes or new interactive services.

What are you talking about? What do you want to adjust? You want a epg.dat in cleartext to edit it yourself? Seem a little bit hmmm well...

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Jay Barberio
How does a user know, when a certain service with a given program number is active or not ? With German paytv provider Premiere the so called option channels are linked via the epg (EIT) to a portal and can be selected accordingly by the DVBViewer. Another, different example relates to channels that split into regional programmes at certain times. This is also covered by the DVBViewer.

 

The end user generally knows that the channel is 'active' when there are programs scheduled for transmission. Getting this information either from the EPG, or from other program information. Or simply by switching to the channel and seeing if it's on.

 

The STB doesn't care if the channel is 'active' or not, and allows the user to select that channel at any time.

 

Let's compare the user experience of a non-technical user buying and installing a DVB-T PVR and someone buying and installing DVBViewer.

 

PVR

1) Bring the kit home, plug it all in, start it up and go through the initial set up.

2) Scan for channels.

3) Find all channels, and be able to look at the EPG data for all of them.

4) Immediately able to set a recording on any of the channels.

 

DVBViewer

1) Install the software.

2) Scan for channels.

3) Realise that some of the channels are missing.

4) Rescan again to see if they reappear.

5) Find channels are still not there. Get confused. Think the software/hardware is broken.

6) Come to the forums to complain.

7) Find out that DVBViewer only finds channels that are currently 'transmitting' video.

8) Wait for the channels to air to re-scan to find them. (Tricky if you want to get some of the channels that run 'Overnight Recording' services.)

9) Finally able to set a recording on any channel.

 

Clearly the end user experience is not very good this way.

 

Certain interactive services from the bbc and other British providers need the implementation of OpenTV. Afaik, you won't find opentv on any stb other than from bskyb.

 

Nothing to do with OpenTV *or* MHEG. OpenTV is not present in any form on DVB-T in the UK. MHEG is only used on 'time-share' channels to give a place holder graphic for channels not currently transmitting.

 

In their 'on' time, the channels are all ordinary DVB channels, sending video and audio in their VPID and APID. In their 'off' time they have no VPID and APID, and send no video or audio.

 

Since DVBViewer ignores all channels without APIDs or VPIDs, this means to get DVBViewer to list all the channels available on UK-DTT you need to re-scan for them when they start airing.

Edited by Jay Barberio

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Derrick
Let's compare the user experience of a non-technical user..
..that makes the choice easy, doesn't it ;)

 

:blink:

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Dvb-tv
What are you talking about? What do you want to adjust? You want a epg.dat in cleartext to edit it yourself? Seem a little bit hmmm well...

No i'm talking about a settings file for the EPG setup...

 

 

WTF within 10 seconds i choose to edit this, to change 'the' to an 'a'.

Result - 'This post has been edited @' can you not set the board for me to make edits. For upto a minute after initial post, like other forums let you do. Before it adds the messy looking 'This post has been editing @' comment

Edited by Dvb-tv

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Tjod
No i'm talking about a settings file for the EPG setup...
Wich settings for the Electronic Program Guide are you looking for?

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Dvb-tv

Which settings...

 

I did not say i needed any settings, for these Interactive channels. I have settings ready to go into DVBViewer, just need an epg settings file to enter them into.

 

I read a while ago. there are plans for seven of these channels for the BBC. Other broadcasters may setup their own at any time.

 

Channels so far have been shown as.

 

301

302

302

305

 

These channels show extra additional videos, making of and repeat showings of special programs. At the moment they show music, jackanory and the making of. Cricket, Parliment and Community all normaly in 16:9-AR. Is why the epg would be good not only to see what is to be shown. But to schedule as with other channels.

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Derrick

If you have the channels, you have the information of the EPG as well. At least what is written in the EIT. Alas for channels which are broadcasted by bsky (also bbc and itv) you won't find any information other than current and next. For a longer preview you'd need a skybox with opentv.

 

ps.

 

Channels so far have been shown as.

 

301

302

302

305

could you give the DVB_IDs of said channnels ? Imho these numbers are taken from a sky digibox and are fixed channels numbers that sky assign to the programmes. Without the proprietary skysoft, nobody will know what you are talking about :)

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Dvb-tv

They are digital terestrial tv not digital satellite tv, though they will be on that platform, i will check.

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Jay Barberio

Any word on if the support for time-shared channels will be considered?

 

This is a totally separate issue from what-ever it is Dvb-tv seems to want, and I'm not sure why he's brought it up in this thread.

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Dvb-tv

In the UK these time shared channels your talking about, BBC3 and BBC4 for one example. Do work and are seen, even their EPG info is there for scheduling, looking at etc. When the share channels are off air.

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Jay Barberio
In the UK these time shared channels your talking about, BBC3 and BBC4 for one example. Do work and are seen, even their EPG info is there for scheduling, looking at etc. When the share channels are off air.

 

Being able to watch them isn't the issue. It's that they don't show up in scans, because DVBViewer always discards channels without video and audio on the assumption that they are data-only.

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Dvb-tv

Ok i see what you mean, i've never found this happening yet. Scan at any time sees all the channels.

 

You could try one scan pre change over, then update the channels after change over. This way you will have all the channels. This is the way older set-top boxes had to be updated. As said with DVBViewer i get all channels on first scan, what ever time of the day it is.

Edited by Dvb-tv

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Jay Barberio
Ok i see what you mean, i've never found this happening yet. Scan at any time sees all the channels.

 

You could try one scan pre change over, then update the channels after change over. This way you will have all the channels. This is the way older set-top boxes had to be updated. As said with DVBViewer i get all channels on first scan, what ever time of the day it is.

 

Just checked, and this isn't what happens with me.

 

Scan at 6:30pm, against the Oxford transmitter, using a TT-Budget with BDA drivers, picks up only the channels active at that time.

 

Can you please confirm that your test scans really do discover all the channels? You might be seeing channels that were picked up in previous scans? An easy test for this would be to check if your scan produces the terrestrial version of the Community channel, which only broadcasts from 6am to 9am.

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Jay Barberio

deleted duplicate post

Edited by Jay Barberio

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Derrick

..you could try TransEdit with "Data Services" checked. Empty PMTs or with private streams only will appear. Then send the list to the DVBViewer-pro with auto-update active and wait what will happen. The empty channels will show as audio services (no v_pid :) ) in the channel list :(

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Dvb-tv

I will try with new beta updates via the application and with transedit. Have not updated since five us and five live became available. With the current beta at that time, will check to see if all is the same.

 

Community channel you want me to check, i never really look at that channel. Normaly check against bbc3 shared with kids tv and similarly with bbc4. I will then check the similarly for you. As Derrick says it is a data service or a interactive stream channel. Which would bring us full circle. To what i was remarking about in a lot of posts above, epg for interactive streamed channels.

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Derrick
epg for interactive streamed channels.

try the analyzer part of transedit and have look at the EIT. DVBViewer is an application that relies on the standard dvb tables. Anything else that is hidden in a proprietary middleware is not covered :(

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Jay Barberio
Community channel you want me to check, i never really look at that channel. Normaly check against bbc3 shared with kids tv and similarly with bbc4. I will then check the similarly for you. As Derrick says it is a data service or a interactive stream channel. Which would bring us full circle. To what i was remarking about in a lot of posts above, epg for interactive streamed channels.

 

I'll repeat myself.

 

These channels are *NOT* interactive streamed services. The Community channel is a normal DVB channel that only carries video and audio at certain times of the day. The problem comes with the developer assumption that anything without a video and audio stream should be discarded, which may work fine on DVB-S but causes problems for DVB-T.

 

A DVB-T compliment channel scan should provide access to all the services provided, if they have video and audio at the time of scan or not! And further, these channels should be updated on channel change, in order to gain the video and audio streams when they do have them. Yes, this will make the scan also produce a lot of 'empty' interactive channels, but the alternative is to miss out on real but time-shared channels.

 

This should be included in the main-program scan. It should only take *one* scan to get all the channels. And no further user action should be needed to get time-shared channels working.

 

There are two moderately simple functionality changes to allow this to work.

 

1) A service scan should provide all services, without discarding ones that have no video and audio.

2) A channel should be automatically updated when the user selects that channel.

 

A DVB-T system should 'just work' following a single scan. At the moment this is not true at all for DVBViewer, which requires multiple scans to find the channels.

 

..you could try TransEdit with "Data Services" checked. Empty PMTs or with private streams only will appear. Then send the list to the DVBViewer-pro with auto-update active and wait what will happen. The empty channels will show as audio services (no v_pid :D ) in the channel list :D

 

This is a work around, not a fix for the problem. I'd like it if the in-application scan worked this way, and this way by default for DVB-T.

 

Additionally, using a lack of video as the test for a radio channel is the wrong way to identify a service type. You should instead check the service descriptor in the SDT table for it's service type value. (1 being TV, 2 being Radio) This is also the way it should be done for all the DVB transmission systems.

Edited by Jay Barberio

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Derrick
I'll repeat myself.

..true ! You did nothing what I asked you to try :D

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Griga
2) A channel should be automatically updated when the user selects that channel.

Options -> TV + Radio -> Automatic Channel Data Update

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Derrick
Options -> TV + Radio -> Automatic Channel Data Update

 

That`s what I've already asked to do :D

Then send the list to the DVBViewer-pro with auto-update active

 

Problem is, that DVBViewer is still not uo to its task concerning "real" dvb-settings.

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Jay Barberio
..true ! You did nothing what I asked you to try :D

 

Um... What you asked me to do was a work around that I've *already done* to get these channels working.

 

What I'm *asking* is for the main application to do these things automatically for DVB-T where its needed, instead of making DVB-S only assumptions. (DVB-S assumptions: channels only rarely need updating so auto-update is disabled by default, anything without video and audio can be discarded.)

 

My request was for auto-update to be switched on by default for DVB-T channels, and the scan to accept all services for DVB-T scans. I already *know* how to use transedit to make a scan and transfer that to the application, and how to switch on auto-update. What I'm saying is I shouldn't have to, that the application should act more like a set-top-box and 'do it right' for DVB-T.

 

Maybe you should stop patronising the paying customers, and listening instead?

Edited by Jay Barberio

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Derrick

so everything is cool, isn't it. you know what to do and others don't care.. :(

 

The DVBViewer is almost as good as transedit :( Here's a scan_sample of altdvb, DVBViewer-pro and transedit. The pro is missing the data channels but the workaround via transedit will get these channels into the pro as well (the names obviously come from the SDT :D;) ) This is just an example of channels having no video or audio elementary stream :D

 

 

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Griga
the main application to do these things automatically for DVB-T where its needed, instead of making DVB-S only assumptions.

The reason for introducing the auto channel update was DVB-S. :D Here in Germany things are different. It is not necessary for DVB-T.

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Jay Barberio
The reason for introducing the auto channel update was DVB-S. :( Here in Germany things are different. It is not necessary for DVB-T.

 

Which part of 'Time-share channels need auto-update to discover when video is active' is unclear? Because of the lower available bandwidth, time-share channels are a big part of DVB-T.

 

so everything is cool, isn't it. you know what to do and others don't care.. ;)

 

The DVBViewer is almost as good as transedit :( Here's a scan_sample of altdvb, DVBViewer-pro and transedit. The pro is missing the data channels but the workaround via transedit will get these channels into the pro as well (the names obviously come from the SDT :D;) ) This is just an example of channels having no video or audio elementary stream :D

 

 

Again, you're not getting that having a workaround is not the same as it being functional.

 

Being able to do it in one scan in the application is what this feature request is about. You shouldn't need to use a second technical aimed application to do something that a set-top box can do automatically.

 

Getting all the channels in one scan is a *core part of functionality* for a TV viewing system and should not require specialist knowledge or use of a specialist tool to get working.

 

This is a *useability* feature request.

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Griga
This is a *useability* feature request.

Well, this "'I'm a customer and I want everything nice and easy so get up your ass and do it" attitude will lead nowhere.

 

The German devs here can't receive your DVB-T channels, they don't experience this kind of problem, and they can't test according enhancements. And yes, there are German DVB-T time share channels, but they handle it in a different way, without temporarily missing streams.

 

Without DVB-experienced users that are willing to participate in a positive, non-complaining way nothing will change in cases like this.

 

Personally I'd like to learn something from it, but this thread is not giving me the input that would be necessary to really do something... attaching the zipped TransEdit XML export of the transponder in question - in a state where the scanner does not find the channels - would be more efficient than just demanding more usability.

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Derrick
in a state where the scanner does not find the channels

From what I understood, transedit's scanning engine does list those channels but this is considered an unacceptable workaround. What I still don't know is whether the imported channels are updated correctly. SDT and EIT from the saved xml would be quite interesting of course.

 

Unluckily there are 2 different topics in this thread. They both have in common that they are based on assumptions for which no evidence is provided..

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Jay Barberio
Well, this "'I'm a customer and I want everything nice and easy so get up your --------------- and do it" attitude will lead nowhere.

 

And a 'stop whining, we know best' attitude won't get you anywhere either. Please try to remember where the money came from in this relationship. At least be polite about it.

 

The German devs here can't receive your DVB-T channels, they don't experience this kind of problem, and they can't test according enhancements. And yes, there are German DVB-T time share channels, but they handle it in a different way, without temporarily missing streams.

 

Without DVB-experienced users that are willing to participate in a positive, non-complaining way nothing will change in cases like this.

 

 

And I am a DVB-experienced user, I've explained the problem, and given you the basic changes that could be made, but the response I got to raising this issue was to wave it off.

 

That German DVB-T doesn't use switching time-share simply means that the devs should pay attention to what people outside of Germany tell them about other DVB-T implementations. And to try and investigate any problems raised by assumptions based on the German implementation.

 

Personally I'd like to learn something from it, but this thread is not giving me the input that would be necessary to really do something... attaching the zipped TransEdit XML export of the transponder in question - in a state where the scanner does not find the channels - would be more efficient than just demanding more usability.

 

You have to actually ask for this information from me before I can give it to you. I'm not a mind reader, I don't know what information you'll need, or what format you want it in until you tell me.

Now that I know you seem to want an XML dump from transedit, I'll send you one.

 

The xml dump is from the Oxford transmitter, with one of the BBC muxs. The time share channels are BBC Four (service ID 16960, on air) and CBeebies (service ID 16832, off air). The file is too large to attach to this post so please provide somewhere I can send it to.

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Griga
Please try to remember where the money came from in this relationship. At least be polite about it.

Yes, SIR, drill sergeant, SIR, of course, SIR! :D

 

Fortunately I don't have to remember :D I'm no DVBViewer.com employee, and I don't get paid for what I'm doing here. Just a spare time thing, like most of my contributions to DVBViewer. Same is true for Derrick and many others. This is not the support hotline of a big international company, but the DVBViewer Community, and if you want to be part of it and get the assistance of the community, don't behave like a picky customer. Wrong address, you know.

 

Why does getting access to such a DVB software and such a DVB software pool cost only 15 Euro? Think about it... usually professional tools like TransEdit are sold for 100 Euro and more. Why do you get it for free after having paid for DVBViewer? Think again - yes, now you're getting close to the point! The devs who made it don't take money for it, all right?

 

simply means that the devs should pay attention to what people outside of Germany tell them about other DVB-T implementations.

Yes sometimes it's quite interesting, from a technical point of view. So if I feel like... well, you're lucky, ATM I do. :(

 

You have to actually ask for this information from me before I can give it to you.

You could have asked what would be helpful and offer your assistance, couldn't you?

 

The file is too large to attach to this post so please provide somewhere I can send it to.

Ok, that's something... I'll PM you and, after having received it, forward it to Derrick. He's the most experienced DVB nerd here.

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Jay Barberio
Yes, SIR, drill sergeant, SIR, of course, SIR! :D

 

Fortunately I don't have to remember :D I'm no DVBViewer.com employee, and I don't get paid for what I'm doing here. Just a spare time thing, like most of my contributions to DVBViewer. Same is true for Derrick and many others. This is not the support hotline of a big international company, but the DVBViewer Community, and if you want to be part of it and get the assistance of the community, don't behave like a picky customer. Wrong address, you know.

 

Hey, if you want to work for a company for free, that's fine. But I still paid money, so should feel somewhat entitled to ask for a product that works properly. Note, I'm not complaining about transedit at all, fine piece of work, does what it's supposed to. (mostly) The issue is with DVBViewer, the piece of software I paid for, that doesn't work in the correct manner.

 

It's not irrational to expect at least a basic 'core functions' support for paid software. I didn't pay money to keep a community going, I paid money to get a working Digital TV system.

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Klaus_1250
Options -> TV + Radio -> Automatic Channel Data Update

 

Silly question perhaps, but what is that supposed to do? I have it checked for as long as I know, but, I still need to fire up Transedit every now and then to find new and changed channels. And using Transedit also means I get a some double channels in DVBViewer, which I need to sort out by hand :-(

Edited by Klaus_1250

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Griga
but what is that supposed to do?

Is was introduced for DVB-S channels that dynamically switch over to different video / audio streams. That means: Service ID and PMT PID remain the same, video and audio PID change on the fly.

 

Some channels of the German ARD handle it this way, e.g. when switching to local news. The ARD provides a test channel for DVB developers (TEST_R on Astra 19° E, 11837 H), that switches between the Phoenix and BR Alpha streams every minute. If Automatic Channel Data Update is ticked, DVBViewer follows... you watch Phoenix for one minute, then BR Alpha, then Phoenix again....

 

And using Transedit also means I get a lot of double channels in DVBViewer, which I need to sort out by hand

TransEdit allows to export selectively and to filter channels that are new. Read the manual. BTW: What about this?

 

 

@Jay: How are the 301..305 & Community channels supposed to work resp. to cooperate with the rest? Are they linked in some way? Can you please explain more detailed?

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Derrick

Automatic Channel Data Update means that changes of an already existing service will be updated in the list. New services won't be found..

 

ps.

imho only the service_id should be considered.

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Griga
imho only the service_id should be considered.

It is done this way, at least in DVBViewer GE. A changed PMT PID triggers the update as well. The above only refers to the ARD method.

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Klaus_1250
Is was introduced for DVB-S channels that dynamically switch over to different video / audio streams. That means: Service ID and PMT PID remain the same, video and audio PID change on the fly.

The "issue" that I have is that my DVB-C provider (TV Home, Netherlands) is adding new channels and changing existing channels quite a lot. They also used to (?) switch over video/audio streams on a few selected channels, but I don't really watch those and don't have them in my current package. DVBViewer seems to have difficulty tracking existing but changed channels, but that might have something to do with the fact that they also change the Service ID and PMT ID's.

 

TransEdit allows to export selectively and to filter channels that are new. Read the manual.

The problem is/was that TransEdit recognized several channels as "new" while they actually weren't new. That caused the double channels (about 25). But that might be related to the above.

 

BTW: What about this.

Will get back on that later. I installled the new beta build of pushsource, and had one instance were the issue occured. But, it didn't seem to work the first time. From what I saw, there were about 3 retries (at least, the MBit counter started and disappeared 3 times) and DVBSource say "Graph too late (169)".

 

Debuglog showed

17.12.2006 16:17:58 WMDVBSource	  erPTSAbove, erPTSBelow

over 100 times, at about 2-7 per second.

 

BTW: Is that the only thing that has changed? I noticed today (but that may be coincidence) that a few channels show a green/red bar for about one frame just before the picture comes up, after a channel change.

Edited by Klaus_1250

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Jay Barberio
@Jay: How are the 301..305 & Community channels supposed to work resp. to cooperate with the rest? Are they linked in some way? Can you please explain more detailed?

 

30x 'channels' on DVB-T are video streams used for special events and side programming. Such as sporting events and live music concerts. They are normal services, and are accessible just like any normal channel, but they are meant to be 'accessed' via interactive services from a main channel. EPG data is not provided for these services.

 

The Community Channel is a single time shared channel, with hours from 6am to 9am. EPG Data is provided.

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Derrick

..maybe we should try to agree to a common definition of what is possible within the scope of the DVBViewer.

 

IMHO all things that require a proprietary software for "interactive services" are definitely outside the scope.

 

What is left are the channels that are only temporarily used. I wouldn't use the term time share cos it's not a shared channel but a shared piece of bandwidth. The problem is that the DVBViewer's internal scanning engine doesn't show these "empty services" in the channel list. A workaround via transedit could solve the problem (good enough for me :) ). In particular with the limited number of channels for DVB-T the use of transedit is fast and efficient.

 

One of the reasons not to consider the so called "data channels" in the internal scan was not to overload the channel list with useless "real" data services. But imho we can agree that the channels in question are not data channels.

 

The solution could be quite simple: All channels that are tv services according to their service_type should be listed whether they are empty or not.

 

e.g. from the "Oxford Mux"

 

  </ServiceID>
- <ServiceID Value="16960" Name="CBeebies">
 <ServiceType HValue="0x01" Name="Digital Television" />

 

The PMT doesn't contain any video or audio stream but it is listed as a tv service. There is even an entry in the EIT which would allow to program a recording when the service becomes active.

 

IMHO the implementation would require only minor changes -_-

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