[TV] Combining Sumultaneously broadcast HD and SD TV channels (1 Viewer)

[robbo100]

Started on: 2011-03-01
last update: 2011-03-01

Summary:

Would it be possible to manually "combine" SD and HD channels where channels are simulcast in HD and SD?

Area:

TV server

Description:

Currently, with ITV1, BBC One and soon Channel 4 (in the UK) these channels are broadcast in both HD and SD. This means that I have to have both listed in the EPG and I pick the one I want to watch (always HD as a preference). It would be great if there was an option to combine these channels so that only one of each channel showed in the EPG.

Clearly there are some complicatons to consider and so the following options might be useful:

- "Always prefer HD"
- "Always record in HD"
- "Stop HD timeshifting to allow HD recording" - with a sub option of "automatically start SD timeshifting when HD stopped for recording"
- "Prompt user to select HD or SD when channel selected for timeshifting"
- "Enable OSD menu to switch between HD and SD streams"

What do you think?

Robbo100

 

[jameson_uk]

It is good in principle until as you say you start thinking about how you prioritise. Even if the channels were on different cards (I get all the HD from DVB-S and normal from DVB-T) then priorities work the other way round for recordings and timeshifting and even then the priority does not guarantee what will be used. Things then get even more messy if all channels are on the same card.

You have the issue that MP does not know what channels are HD and which are SD (I guess in theory there is nothing to stop some broadcaster somewhere having both SD and HD on the same channel ?).

what happens if (like me) you only have a single HD tuner and want to record something on BBC and Channel 4 at the same time? which one should be in HD ? What about users who have CAMs for decoding and are unable to decode more than one encrypted channel at a time? Basically there are so many different factors that even without this the card allocation code is incredibly complex.

In theory is a great idea but unfortunately I think the effort needed to implement this would be massive (and prohibitive )

 

[revs]

Would prioritization not just work the same was as it does with SD channels?

I have seen there is a priority screen in MP that lets you put one schedule above the other, the same would be the case for HD vs SD.

'what happens if (like me) you only have a single HD tuner and want to record something on BBC and Channel 4 at the same time' - would it not look at the current priority functionality in MP, record the top priority item in HD, and then the next in SD?

Simple scenario:

TV Server is set to record.
1. Check if channel is available in HD
2. Check HD channel is available
3. if available, record in HD, else look for SD version of channel. If available then record, else no record possible

Probably not so simple for development, but logic wise I dont think its too difficult.You simply check to see if the HD channel is available before recording

 

[robbo100]

Jameson,

Without a shadow of a doubt, you know much much more about this than I do, but as Revs says, much of what you describe is very similar to current MP TV Service operating constraints already.

For example:

what happens if (like me) you only have a single HD tuner and want to record something on BBC and Channel 4 at the same time? which one should be in HD ?

The current system would just pick the first recording set-up, and if when the second one is setup there is no spare card, you are given the option to skip the recording (or in this case you could downgrade it to SD perhaps).

What about users who have CAMs for decoding and are unable to decode more than one encrypted channel at a time?

Similarly, the tuner card has an associated CAM which has a CAM limit. Currently the same option to skip the recording would be given in this instance (and select SD if this is available without the CAM).

Ultimately though, you are right in that it is more complicated, and I am not the person who will code it (since I don't know how to ) so I completely accept your expert opinion. - would be a nice feature though

Robbo100

 

[revs]

I'll add it to my 'mediaportal coding projects i'll never get round to doing'

I guess the non-coding solution (if you have a seperate DVB-S and DVB-T card) is to merge the channels (the SD and HD), and make the DVB-S card a higher priority than the DVB-T one. In theory the TV Server should then try to use the HD channel first

 

[jameson_uk]

much of what you describe is very similar to current MP TV Service operating constraints already.

With one big key difference; the current logic is only based on cards so having separate DVB-T and DVB-S cards actually makes things slightly easier. To implement this properly you need to have some sort of priority based on channel. This then potentially disagrees with the current card priority logic though....

I'll add it to my 'mediaportal coding projects i'll never get round to doing'

LMAO I have a big list for that too

I guess the non-coding solution (if you have a seperate DVB-S and DVB-T card) is to merge the channels (the SD and HD), and make the DVB-S card a higher priority than the DVB-T one. In theory the TV Server should then try to use the HD channel first

But priorities work the other way round for recording and timeshifting. If you set the priority of a card this will make it either the preferred card for recording (which will make it the least preferred card for timeshifting) or make it the least preferred for recording (making it the most preferred for timeshifting)

This is why I think that this would need to be reworked as what if you have HD channels on DVB-S and DVB-T (but not the same ones). If one HD channel is only on card 2 but others are on card 1 then the current card prioritisation code would stop this idea working.

When TV server was built HD channels did not really exist so it was not coded for this type of thing. Hopefully when we develop TVE4 or the next version for MP2 we will be able to build this sort of thing in. For now, I think it is a massive amount of work. If someone was to create a patch for it and code it up then I am sure it would be considered but does anyone have a few months spare

 

[DieBagger]

That would be also very helpful if clients are connected over wifi. Client a which is connected over gb lan could automatically tune the hd channel whereas client b (laptop, mobile) would start the sd channel.

Cool idea!!!

 

[funkstar]

That would add another layer of complexity DieBagger, especially as MP has no knowledge of how it is connected to your network. A client would have to detect it and report back to the server, or you set it in preferences somewhere and that setting it shared with the TV server.

My view is this could get overly complex

 

[DieBagger]

I wasn't talking about some automatic bandwidth detection, just a setting (prefer sd/hd) for the user to decide.

 

[revs]

But priorities work the other way round for recording and timeshifting. If you set the priority of a card this will make it either the preferred card for recording (which will make it the least preferred card for timeshifting) or make it the least preferred for recording (making it the most preferred for timeshifting)

Wait - this sounds silly.. So I set my preferred card. And that is used first for time shifting. makes sense.

Say no cards are being used, and I have a recording, the card that will be used is not the top priority one, as this is now the least prefered? This explains some bad recordings I have!