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Hi-Fi AM demodulator testing w/IBOC

And the buffering is no different than what happens to online listeners. Actually I think the whole trying to sync radio audio with TV audio is stupid. After all for those of us with Directv the audio still isn't in sync.
 
IBOCRocks: "Not really. There is a "sports flag" built into the HD spec so that radios fall to analog during sporting events. So it's working as planned."

What a joke - that's progress for you ! Just like, when the IBOC signal goes out of range, it reverts to analog ! :D
 
A joke indeed! What a terrific HD system that has a flag to turn it off ---that should really tell you something.

The reason TV and radio need to be in sync is some radio listeners still watch TV and like their "radio" announcers calling the game. It would have been smart to have had a "digital delay time" standard years ago that would have made satellite radio, DirectV, HD, and Internet (the basic encode delay at least), all in sync. Now each system varies by a second or more. I "use" the XM delay to hear a replay of a ballgame run by switching back and forth from analog AM to XM!
Most listener/viewers only complain that they don't sync up. Many viewers buy HD and then find out they need to watch the analog channel so it syncs with the radio. A few models of newer digital cable boxes also delay ALL channels by a couple seconds, including analog channels. A real pain, one ends up putting coax switches back in to bypass the cable box and run the channel directly to the tv set. It's as if the developers have NO idea how the boxes/sets are used in the real world.
 
Ray22 said:
A joke indeed! What a terrific HD system that has a flag to turn it off ---that should really tell you something.

The reason TV and radio need to be in sync is some radio listeners still watch TV and like their "radio" announcers calling the game. It would have been smart to have had a "digital delay time" standard years ago that would have made satellite radio, DirectV, HD, and Internet (the basic encode delay at least), all in sync. Now each system varies by a second or more. I "use" the XM delay to hear a replay of a ballgame run by switching back and forth from analog AM to XM!
Most listener/viewers only complain that they don't sync up. Many viewers buy HD and then find out they need to watch the analog channel so it syncs with the radio. A few models of newer digital cable boxes also delay ALL channels by a couple seconds, including analog channels. A real pain, one ends up putting coax switches back in to bypass the cable box and run the channel directly to the tv set. It's as if the developers have NO idea how the boxes/sets are used in the real world.
Click to expand...

You do understand that ANY form of digital broadcasting has a delay, right?
 
I've never heard of this flag.......where can I read about it?
 
---->It would have been smart to have had a "digital delay time" standard years ago that would have made satellite radio, DirectV, HD, and Internet (the basic encode delay at least), all in sync.

Physically impossible.

The delays are often caused by satellite hops. One or two.

For example, the baseball game is fed back for radio using a phone line, with ADA conversion.

TV comes back with a five second obscenity delay, plus the sat hop delay, plus the encoding into HD delay (and simultaneous SD delay), plus the digital tuning delay at the set top box.

Add to that, the delay for getting the TV signal back to the DBS uplink (could be via satellite with dealy, or could be via Vyvx with no delay). Then, a compression delay at the sat uplink, plus another sat delay for the updown there.

Digital devices all encode-buffer decode at different rates.

Synchronization is impossible nowadays.
 
zumahans said:
---->It would have been smart to have had a "digital delay time" standard years ago that would have made satellite radio, DirectV, HD, and Internet (the basic encode delay at least), all in sync.

Physically impossible.

The delays are often caused by satellite hops. One or two.

For example, the baseball game is fed back for radio using a phone line, with ADA conversion.

TV comes back with a five second obscenity delay, plus the sat hop delay, plus the encoding into HD delay (and simultaneous SD delay), plus the digital tuning delay at the set top box.

Add to that, the delay for getting the TV signal back to the DBS uplink (could be via satellite with dealy, or could be via Vyvx with no delay). Then, a compression delay at the sat uplink, plus another sat delay for the updown there.

Digital devices all encode-buffer decode at different rates.

Synchronization is impossible nowadays.
Click to expand...

I had an interesting conversation with some engineers the other day...as you know lots of people watch the game on TV with the radio for the audio. Well, the delay on TV is different for HDTV, Satellite, Cable, etc. They had a big debate on what to set the radio delay for! I think in the end, cable was the winner!
 
That works fine, unless you have a lot of people listening to the radio at the game.

If KFWB delayed the PBP feed at Dodger home games (they don't), there would be 50,000 angry fans.
 
zumahans said:
That works fine, unless you have a lot of people listening to the radio at the game.

If KFWB delayed the PBP feed at home games (they don't), there would be 50,000 angry fans.
Click to expand...

I had heard of one station broadcasting the feed on an on-channel LPAM transmitter non-delayed at the ballpark. Don't know if it was an urban legend or not.
 
My point was IF a delay standard WOULD HAVE been set years ago we would be closer than the mess nowadays. Since all the developers of digital knew there would be a delay...would have been nice to have this hashed out before now...and yes, I do realize it's too late now! The encoder/decoder delays could have been set for example. Some of the Sat. hops stuff is really minor compared to the digital encode/decode of present day digital systems.
There are plenty of people that still use radio live at sporting events, from hockey to baseball. And yes, many arenas do have LPAM or LPFM transmitters that are fed almost delay free audio for fans with radios.
Viewers/listeners DO TRY to make things sync by bypassing cable boxes, etc. It is a bigger deal to consumers than engineers may think...from the calls and questions I receive re this subject.
The Qualcomm MediaFLO will also have to deal with the delay when fans are using their videoTV cell phones at a sporting event. But the MediaFLO did get their delay down to less than HD and some other systems.
 
My feeling is that you can not operate a radio station to please a relative handful of listeners sitting in front of their television or in stands out at the ballpark. If you subscribe to MLB.com which is streamed over the internet that too has delayed audio and video. We live in a world where buffering packets is a reality, whether it be via HD radio, streaming on the internet or the multiude of compressed digital television feeds and DirecTv as well as Dishnetwork have different delays than say a local cable operator. Even the cable suystems who take their feeds via C band will notice some delay due to the transmission path as opposed to what we see on our over the air feeds. What is or isn't acceptable is a matter of opinion. The whole HD delay issue is a non issue in my opinion.
 
If the digital "minor delay issue" was really a "non-issue" then why does HD have a "sports flag." You can't have it both ways... ::)
 
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