23 replies to this topic

[daveraver]

hi all, I wonder wich is the 4k bitrate.
full hd is over 10mbit/s. Would full 4k be between 19-25mbit/s ?
thanks in advance.

[Trial]

Hi,

most on Astra/Hotbird I can see are around 17-19. Hotbird 4K1 is and exception with 28MBit. I would gues that there will be 2 services on 1 transponder when they are live on air.

 

ciao

[daveraver]

thanks!!

Edited by daveraver, 2 July 2018 - 15:20.

[Erik Slagter]

4k bitrate can be anything between 1 kbps and about 64 mbps. It really depends on the frame rate, the amount of detail, what codec is used, how smart the codec is, how the codec is configured, the bit stream constraints, the quality setting etc etc etc.

Edited by Erik Slagter, 6 July 2018 - 09:34.

[daveraver]

yes, of course, I mean which would be the standar quality we could find on satelite channels... reading on www I saw it is 19-25mbps... So which would be the capacity of streaming 4k channels for a fast ethernet 10/100?? it would be limited for cpu and ram memory... We guess I am talking about zero 4k... but there are so few 4k channels... sadly... really very poor...

Edited by daveraver, 9 July 2018 - 22:31.

[Erik Slagter]

There is no such thing as a standard quality nor a standard bitrate.

 

I don't understand what you're trying to achieve.

[Trial]

Hi, the quality/bitrate will be defined by the size of the wallet of the service provider. More money = higher bitrate. We will see a wide variety of bitrates. ciao

[littlesat]

Higher bitrate != Picture quality... It feels like this the only relation but actually it doesn't....

 

There is more involved here...

 

HDR HSL New v.s. Older encoders 8, 10, 12 bit color dephts, 4:2:0, 4:2:2... enz.....

 

And for UHD the variance of parameters is event bigger than it was before

 

With MPEG2/4 the practical only variance are New v.s. Older encoders... Newer encoders give a much more better picture at lower bitrates compared with let's say the first generation encoders.... 

Edited by littlesat, 11 July 2018 - 10:49.

[Trial]

Hi,

OK I agree. But we can say: More money = higher bitrate = chances are good to get better quality:-)

 

ciao

[WanWizard]

No, on the contrary, in general more money means better equipment which means same or better quality at lower bitrates !

[littlesat]

OK I agree. But we can say: More money = higher bitrate = chances are good to get better quality:-)

 

Also that is not (fully) true.... as newer encoders are also more expensive than the older (2nd hand) encoders...

Edited by littlesat, 11 July 2018 - 13:57.

[daveraver]

There is no such thing as a standard quality nor a standard bitrate.

I don't understand what you're trying to achieve.

I am not on the way to achieve anything, just discuss about tech and bitrate. I meant which bitrate would be the most common to be used on each satelite. I guess the bandwidth you spend to broadcast a channel define what you pay. each TP has a capacity, you pay for each Tp, there are several categories of tp, capabilities, so on 4k generation, we can define the optimal bitrate to make an optimal management of satelite resources. I think 4k gen. needs new satelites... is IPTV on the way to put a final dot to satelite??? there are lots of things I cannot discuss in english... I am sorry...

Edited by daveraver, 11 July 2018 - 15:20.

[WanWizard]

Point is that there is no optimal bitrate.

 

Bitrate will always be in function of the way the encoders are configured, taken into account the commercial goals of the provider. Some will be able to live with 2 UHD channels per transponder (and therefor have 40Mbps on average available per channel), some will have to squeeze 8 channels or more on a transmitter. 

 

It is very noticable when you look at the Soccer live broadcasts over the last few weeks, compare the bitrate of a BBC transmission with that of an M7 transmission of that same game for example.

[littlesat]

Yes... NPO 1 UHD via M7 is much better than the BBC ???? or ITV

[daveraver]

well, there is no optimal bitrate, but there is a limit of transmission from a satelite. hd channel has 10-12mbit/s as top bitrate. to manage the resources of astra 19.2° to transmit 4k... there is the bitrate point...
I think the capabilities and the number of 4k channels will set the average bitrate we can give to the channels.. of course

Edited by daveraver, 11 July 2018 - 22:52.

[WanWizard]

Not true, if you watch F1 on Sky for example (UK or DE), the bitrate is often much higher than 12Mbps.

 

It will always be a combination between available money (to buy transponder bandwidth), and the quality and configuration of the encoders. Often you see higher bitrates on cable for the same channel, because bandwidth is cheap.

[Erik Slagter]

To add to that, that does not per sé mean the picture quality is better on DVB-C, just that they can afford to use older / cheaper encoders.

 

Then there is the factor client devices and technical knowledge, e.g. Discovery Networks and Viacom (MTV). Apparently these two really don't give a **** about quality and how (to simply) improve it, I think they just don't know (and don't care). Factor client devices: not all SoC can decode all codecs and all profiles/leves. The broadcaster has to consider that (or replace $$$ them).

 

It's really all not that simple.

[littlesat]

When you use 12 Mbps for a HD channel there will be no real difference experienced between an old and newer encoder... when we scale it down to 6 Mbps a new encoder will give (approx) the same picture quality experience than an old encoder on 12 Mbps...

Edited by littlesat, 12 July 2018 - 20:05.

[daveraver]

Well, I have found how a channel bitrate is improved and will become more efficient. The new DVB-S2X will be useful to make an efficient use of the whole bandwidth of a satelite. 

 

https://en.wikipedia.org/wiki/DVB-S2X

 

spanish wiki seems to have wider information (you can translate)

 

https://es.wikipedia.org/wiki/DVB-S2X

 

greetings,

Edited by daveraver, 13 July 2018 - 17:40.

[daveraver]

Or I think so...