Uplink Activity Wednesday, November 16th 2005

[John Kotches]

Actually, it seems to me that 8PSK is indeed compression, just as QPSK is compression. Lossless compression in this case, which is a good thing.

8PSK is a data delivery method, not a compression method. The next step is HPSK (Hexdecimal Phase Shift Keying), with 16 states per symbol or the equivalent of 4 bits/symbol. Twice the efficiency of QPSK.

Is FM stereo a compression scheme? That's the same logic you're applying.

Cheers,

 

[mdonnelly]

8PSK is a data delivery method, not a compression method. The next step is HPSK (Hexdecimal Phase Shift Keying), with 16 states per symbol or the equivalent of 4 bits/symbol. Twice the efficiency of QPSK.

Is FM stereo a compression scheme? That's the same logic you're applying.

Cheers,

Do you get more data than the previous transmission method? That's what I mean by compression. Yeah, I understand, it's just like data modems. Change the modulation, get more data.

 

[GeorgeLV]

Do you get more data than the previous transmission method? That's what I mean by compression. Yeah, I understand, it's just like data modems. Change the modulation, get more data.

Yeah, thats the problem too. Just as modems needed higher quality lines to work at the higher speeds the new modulations offered, the transmission path from the satellite to your house must be of higher quality. The transponders need to send out a stonger signal or you need a dish with more gain for the signal to be understood.

 

[ronjohn]

Do you get more data than the previous transmission method? That's what I mean by compression. Yeah, I understand, it's just like data modems. Change the modulation, get more data.

There are two ways to get more data, 1) a bigger pipe, 2) push more data thru the same pipe.(this is compression)

Changing the modulation is changing the size of the pipe, not compressing data to fit on the same pipe.

The reason people do not like compression is that the video is usually affected negatively. (You can see pixelation in action videos) Changing the modulation will not affect video quality. The issue that it may cause is the ability to receive the sattelite signal.

 

[SimpleSimon]

What do you think a scan line is other than a collection of pixels?

Yeah, but you're counting them sideways.

There are 1080 scan lines in a 1080i transmission. The difference is in the number of pixels (1280 or 1920) per line. Note that this does NOT affect the visible width of the picture, just how dense the pixels are horizontally.

 

[RVD420]

Couldn't Dish upconvert the SD channels into HD until an HD version of the channels come about? That would be better than no HD at all for a while wouldnt it?

A better idea would to not compress the hell out of a channel. SD looks good at 8Mpbs.

A non overcompressed Sd signal looks better than an overcompress SD to HD upconvert.

 

[John Kotches]

Simon,

I never did like the way we counted the screens... I always thought 1080x1920 was a more natural description Then again, I'm left-handed living in a right-handed oriented world so most everything seems backwards to me.

Yeah, they're vertically filtering from 1920 to 1280. If I think of it in terms of a raster, then it's much easier to keep it straight. Damn, but that's an antiquated way of keeping it straight, isn't it?

Cheers,

 

[M Sparks]

I remember from somewhere (cant remember where) that the voom package is going away and its gonna be all added to the hd package at no cost at the first of the year.. Im sure some one will find that link or correct me if im wrong.

Probably been covered, but yes. Part of Voom's contract with everyone (not just Dish) is that all 21 channels must be carried, and they must be in a "HD Basic" tier.

This is why I have always believed that either Voom 21 would be launched in MPEG-2, or that all HD recievers would get swapped for free.

There will be a lot of new HD launched in the next year. I think that we will see something like HD Top 30 which will initially be in MPEG-2 and HD Top 40, which will require MPEG-4. We already potentially have 27 MPEG-2 HD channels. Maybe round it out with Universal and call NBA/NFL the other two.

When they launch MPEG-4, there will be INHD 1 & 2, Wealth, Outdoor, Food, HGTV, Fox, NatGeo, MHD, and hopefully TCM...there's your HD Top 40 right there. Or throw in The Movie Channel HD and Encore HD ala AT180.

Adding/swapping dishes is cheaper than receivers. They may not even have to do that. They still run ads for Starz and the other premiums that say "8 channels with Dish 500, 6 channels with other systems." If you saw an ad that said "30 channels with DISH 1000 or 2 dish systems, 8 with DISH 500", wouldn't you pony up a few bucks to upgrade?

 

[bpasker]

Before I go buy the equipment to add the 61.5, can someone tell me if my ebay shopping list is accurate?

1. Single LNB?
2. 18 inch dish
3. SW21?

I want to connect this to my dish 500 that is pointed at 110 and 119 currently through the sw21, is this all I need besides the obvious coax cable? And what if I get another DP LNB that is meant to see 110 and 119? I see where there is some trick posted about covering up one side for a while, do I really want to be messing with that?

 

[BFG]

Big important difference in wether you currently have a dish pro 500 or a dish 500

If you have a dish pro setup, you need a dish pro lnb and a DP21

if you have a regular legacy setup, you need a legacy LNB and a SW21

see this thread for info about adding 61.5 - http://www.satelliteguys.us/showthread.php?t=66374

 

[HokieEngineer]

I think I finally got to the bottom of the "turbo" firmware update. The updated firmware that is out or coming out is for qpsk turbo 7/8 fec. Currently there is only one TP out of all their sats that is using this, and its a mpeg4 test on 129. However, this could mean they would be deploying qpsk turbo more widely in the future.

The one thing I got out of this was that there is no change to the 8psk they are using, so we'll continue to see a max of 3 HD channels per transponder there.

So, we were both right it seems! New firmware with new code for the broadcom decoder. However it was for qpsk not 8psk.

 

[Smith P.]

8PSK is a data delivery method, not a compression method. The next step is HPSK (Hexdecimal Phase Shift Keying), with 16 states per symbol or the equivalent of 4 bits/symbol. Twice the efficiency of QPSK.

Is FM stereo a compression scheme? That's the same logic you're applying.

Cheers,

In DVB-S2 standard mentioned 16APSK and 32APSK, are you made up the HPSK term ?

 

[Smith P.]

I think I finally got to the bottom of the "turbo" firmware update. The updated firmware that is out or coming out is for qpsk turbo 7/8 fec. Currently there is only one TP out of all their sats that is using this, and its a mpeg4 test on 129. However, this could mean they would be deploying qpsk turbo more widely in the future.

The one thing I got out of this was that there is no change to the 8psk they are using, so we'll continue to see a max of 3 HD channels per transponder there.

So, we were both right it seems! New firmware with new code for the broadcom decoder. However it was for qpsk not 8psk.

The method should be used for SD receivers, but the old legacy will be out.
Will be interesting to see advantage QPSK_TC_7/8 vs 8PSK.

 

[Smith P.]

I think I finally got to the bottom of the "turbo" firmware update. The updated firmware that is out or coming out is for qpsk turbo 7/8 fec. Currently there is only one TP out of all their sats that is using this, and its a mpeg4 test on 129. However, this could mean they would be deploying qpsk turbo more widely in the future.

The one thing I got out of this was that there is no change to the 8psk they are using, so we'll continue to see a max of 3 HD channels per transponder there.

So, we were both right it seems! New firmware with new code for the broadcom decoder. However it was for qpsk not 8psk.

There are no MPEG-4 on 129 tpn 13 !

Regular MPEG-2: one HD, other SD [ABC].

 

[goaliebob99]

Thanks for the update Psmith its allways welcomed here

 

[John Kotches]

In DVB-S2 standard mentioned 16APSK and 32APSK, are you made up the HPSK term ?

I'm adding bits to the end to go to 4-bit (Hexadecimal) and 5-bit (32-bit data), and don't have access to the approved terms. Thanks for passing them along to me!

It's too bad they didn't use HPSK, as that's a lot less unwieldy than 16APSK.

Cheers,

 

[SimpleSimon]

Simon,

I never did like the way we counted the screens... I always thought 1080x1920 was a more natural description Then again, I'm left-handed living in a right-handed oriented world so most everything seems backwards to me.

Yeah, they're vertically filtering from 1920 to 1280. If I think of it in terms of a raster, then it's much easier to keep it straight. Damn, but that's an antiquated way of keeping it straight, isn't it?

Cheers,

I'm left-handed, too, but this STILL has NOTHING to do with "vertical". You're not thinking backwards, but sideways. Just because YOU think it's more natural doesn't mean anything - unless you never want to communicate with anyone.

The raster (vertical scan line count) is 1080. Period.

They are "filtering" (your word) the HORIZONTAL from 1920 to 1280.

 

[John Kotches]

Simon,

They are "filtering" (your word) the HORIZONTAL from 1920 to 1280.

That's not my word, that's what happens. You take a 1920 originating broadcast and ship it out at 1280. In the case of Voom, we are getting 1280x1080 content. Since Voom claims to be capturing at 1920x1080 (and I have to take their word for it), then they have to get to 1280x1080 with some form of filtration. You've just reduced by 1/3 your horizontal resolution. How do you do that? It's not black bars at 1/6th picture width on either side of the screen is it? Nope, so you have to do a few things to make the image work.

Because 1920 can capture details that can't be displayed at 1280, you pass the image through a low-pass filter to remove information that exceeds the Nyquist limit for 1280 horizontal pixels. It works the same as audio processing in that respect.

There is also additional processing on top of that to maintain aspect ratio as well. Whether you want to call that a filter or not you're welcome to debate.

Cheers,

 

[lakebum431]

So back to the fun part of this thread. Any new developments on the newly uplinked channels? Tomorrow is Wed, could it be another exciting day?

 

[CJPC]

Well, as long as goaliebob99 puts his new xbox away, I think we will be ok