Why Can't Our Receivers Decode 4:2:2?

[Alan Rovner]

Hi guys I'm naive in this area. Why can't our Linux based receivers decode and display 4:2:2 content like ABC and CBS feeds? I can watch them using VLC on my PC. Why can't this functionality be embedded into TNAP firmware?

For that matter what does 4:2:2 represent? A CODEC? A modulation scheme? As I said I'm naive in this area.

Thanks,
Al Rovner, K7AR
Vancouver, Wash.

 

[comfortably_numb]

Depending on which receiver it is, you can stream the 4:2:2 channel from your receiver to a computer.

 

[primestar31]

For that matter what does 4:2:2 represent? A CODEC? A modulation scheme?

It defines the CHROMA of the signal. Chroma Subsampling: 4:4:4 vs 4:2:2 vs 4:2:0

What's so special about it, well, that I don't know...

 

[Alan Rovner]

Numb, yes I'm aware of the computer streaming. That works fine, I'm wondering why the same ability isn't included in the firmware.

Al

Sent from my Pixel 6a using Tapatalk

 

[Jim S.]

I doubt you'll get a straight answer on this one. Every time I ask why no receivers support it, the answer is always "the chipset doesn't support it". So then I ask "why can't it be done in software?" And the answer is always "the CPU isn't powerful enough". My final question of "why aren't they putting more powerful CPUs in them, it really shouldn't take that much these days?" always goes unanswered.

 

[Alan Rovner]

Thanks Jim your comments make sense. I think adding such capability would be a great feature and would distinguish such a receiver from the competition. We can hope.

Sent from my Pixel 6a using Tapatalk

 

[comfortably_numb]

My question is, when a 4:2:2 is streamed from a receiver to the computer, isn't the receiver's CPU still doing the "heavy lifting," so to speak, or is it the computer doing the decoding?

 

[Alan Rovner]

I'm guessing the receiver sends raw network data to the PC and software like VLC does the heavy work.

Sent from my Pixel 6a using Tapatalk

 

[arlo]

Pretty much the codecs, that are chunks of software, are burned into the receivers chipset. And the chipset codecs work on the way out to HDMI. Unlike your pc where you can install codecs, chipsets not having codecs such as those needed for 4:2:2. And not offered as microcode by the chip maker. Just won't be able to decode what wasn't engineered in them in the first place.
It's not really an E2 thing. E2 developers are at the mercy of how far a chipset maker will disclose info. to them.
The geeks that be months ago decided that NASA UHD needed a version of 10 bit codec that resulted in tons of receivers suddenly producing a garbled or no video at all.
You may think of it as a UEFI/BIOS update on a motherboard that opens new options. None available on FTA receivers.
Even streaming using VLC on a pc didn't give a picture until you downloaded the correct codec from the MS Store or found it in a Google search.
NASA didn't take long to reverse the change. Most definitely due to the masses griping.
So you could think of your receiver not natively showing a 4:2:2 picture as having the audio/video signal split internally in the receiver. One Y split going to the receivers audio/video processor and the other going out over LAN.

 

[Alan Rovner]

Guys thanks for all your comments. I better understand what the issue is now.

Sent from my Pixel 6a using Tapatalk

 

[arlo]

Kind of sorta' thinking if a software transcoder for E2 could be developed.
One that worked like the upscaling in the video menu does to display lesser formats as 1080.
Seems like if 4:2:2 can be streamed over LAN the stream could be looped back and passed through.
A 4:2:0 picture would be acceptible if the hardware could handle the load.

 

[Captain Midnight]

I recorded some feeds recently and noticed the 4:2:2 files were nearly 4x the size of the 4:2:0 files of similar length. There is clearly a lot more data involved to process but I still don't understand why there hasn't been a receiver built to handle it without streaming it someplace else first. How is everyone else streaming it? I'm just getting time to set up the Mio I bought. I have heard it can be streamed to an Apple TV unit with great results.