Is QPSK the same as 4:2:2?

[caddata]

I see that my Twinhan will decode QPSK. Haven't heard the term used here.

 

[qwert1515]

Is QPSK the same as 4:2:2

Nope, Quadrature Phase-Shift Keying (QPSK) is a signal modulation, 4:2:2 is a video profile or Codec (Compression).

So for QPSK think about AM and FM radio, and for 4:2:2 think about a video compression format like dvix or mpeg2.

The Twinhan can pick up QPSK signals and it can also display 4:2:2 if you have the right codec's and software installed on your computer.

 

[Tower Guy]

I see that my Twinhan will decode QPSK. Haven't heard the term used here.

QPSK is Quadrature Phase Shift Keying and refers to the modulation method used in conventional satellite transmissions such as DVB.

Some transponders are now using 8PSK and DVB-S2 encoding. This halves the transponder space, but requires a larger dish. Only newer receivers have DVB-S2 capability.

4:2:2 refers to the sampling rates of the Luminance and Chroma difference signals where 4 is 13.5 mHz and 2 is 6.75 mHz for standard definition video.

4:2:2 is used primarily for backhauls of SD events for high-end sports. Most MPEG2 satellite distribution transmissions are sampled at 4:2:0 which means that the Chroma difference signals are digitized on alternate scan lines.

 

[caddata]

....The Twinhan can pick up QPSK signals and it can also display 4:2:2 ....

I read where the Quali-TV will decode the QPSK compression and 4:2:2 MPEG2 compression also.

I haven't tried the Twinhan on 4:2:2, however it works great with regular MPEG2. So is it likely that if my Twinhan is decoding 4:2:2 MPEG2 then it should also decode the QPSK as well?

Thanks Guys, I appreciate y'all taking the time to fill me in on this.

Harold

 

[digiblur]

I read where the Quali-TV will decode the QPSK compression and 4:2:2 MPEG2 compression also.

I haven't tried the Twinhan on 4:2:2, however it works great with regular MPEG2. So is it likely that if my Twinhan is decoding 4:2:2 MPEG2 then it should also decode the QPSK as well?

Thanks Guys, I appreciate y'all taking the time to fill me in on this.

Harold

You need to reread the replies above....QPSK isn't a compression, it's a modulation scheme.

I haven't seen a residential FTA receiver whether it is PCI, STB, etc based that doesn't tune QPSK signals.

The Twinhan doesn't care if it's 4:2:2, 4:2:0, MPEG2, MPEG1, MPEG4, or whatever other compression scheme you can drum up, it just demodulates the signal and passes the data down to the software you are using.

 

[caddata]

....QPSK isn't a compression, it's a modulation scheme....

Thanks for setting me straight on that Digi I wasn't watching what I was typing.

There's a FTA radio service on R4 I'd like to listen to that uses QPSK modulation. Being unfamilar with it, I thought it was some sort of encription.

Thanks again to all for the all the information.

Harold