ATSC Digital TV - Digital Radio not HD Radio

[kfbkfb]

The current ATSC DTV standard includes (up to 5.1 channel)
Dolby Digital.

Our local PBS station KCPT 19 leaves their DTV encoder set for
a 4 program multicast overnight even though 19.3 and 19.4 are
not used (they have a video signal that says they are on from
6AM to 6PM, there's no audio)

Although ATSC DTV wasn't designed for mobile/portable reception,
it seems to me the audio of 19.3 and 19.4 could be put to good
use by retransmitting (for example) our 2 News/Talk AM stations
(KCMO, KMBZ).

If Surround Sound (without video) catches on, ATSC DTV could be
used to transmit it without needing FCC approval.

There may also be another DTV based audio only option, depending
on the outcome of Mobile ATSC research:
http://groups.google.com/group/alt.video.digital-tv/browse_thread/thread/e7f74bcf0c553508#

Kirk Bayne

 

[Kelly]

For TV, surround sound has already caught on. Trust me, there are a lot of "AV Geeks" out there, and love their 5.1 surroung

Because most cable TV boxes have a hard time re-syncing when switching between stereo and 5.1, (makes a big POP in the audio and takes several seconds for audio to return), most stations that do any 5.1 audio will leave their Dolby(tm) encoder in 5.1 mode, then will "up-mix" their audio prior to the audio encoder. With up-mixing, the digital steam includes only information in the Left and Right channels, and zeros only in center and rear, still active channels, just no audio. The up-mix is accomplished by switching the audio processor ahead of the encoder between surround pass-through then process, or up-mix mode between stereo and 5.1 programming. The left and right channel audio levels are adjusted accordingly to appear as stereo at home. Assuming you attempted to feed unique audio into unused channels, anyone with a 5.1 system at home would be able to hear any audio you fed into the center, or rear channels.

As you pointed out, the ATSC is working on a mobile standard for delivery of DTV signals. Depending on how many HD and "dot"-SDTV channels a station operates, there has been discussion of using some of the TV station bandwidth to transit essentially radio broadcasts. In that regard, one could deliver data files verses live stream via DTV stations also. In Japan, the government forces TV stations to cooperate in delivery of mobile-TV programs via a cellular approach, in that all the local TV stations must carry the same mobile TV and emergency information data.

To that point, why the US, and the ATSC needs to reinvent the standard for delivery of video and audio to mobile devices via DTV signals, when countries in Asia had an established standard which works well seems silly. But there again, COFDM was proven and used as a digital modulation standard in Europe and Asia for several years before the US was even thinking about DTV, but we had to invent a completely new DTV standard in 8VSB.

 

[Mike Walker]

Surround sound for radio is a dead issue (as it has been for the last 35 years, since it was attempted in the early-mid 70s) for a very good reason...99.99 percent of recorded music is in two-channel stereo, or mono. And a HUGE percentage of FM listening is still in mono, on table radios. Then there are boomboxes, walkman portables, car stereos, etc...the devices people actually use, none of which could easily support surround (if at all...ok, car audio systems could...but so what?)

Besides, when the FCC mandated in band, on channel (IBOC), by default they chose very limited bandwidth for audio delivery (particularly if multicasting is to be used). Good stereo beats bad surround (and the bitrate wouldn't increase just because the number of channels did!) ANY DAY!

 

[kfbkfb]

Both Multichannel SACD and DVD-Audio offer Surround Sound
(without video), both formats have done poorly in the US market.

The Freeview Digital TV system in the UK also has many
radio stations available (I don't know if they are in stereo):
http://www.freeview.co.uk/channels/radio

Kirk Bayne

 

[kenglish]

I always wondered why the big news stations (like the one I work for) don't try something like a "long form" news/features channel, using audio only.

I envision something where certain (but not all) news and features, that have some sonic quality to them, be done with full surround sound. Imagine a "recorded live", long-form report, from an outdoor music festival. A re-opening of a historic church or cathedral. An Outdoors segment on white-water rafting, or the sounds of a deer (hunting) camp at night, complete with crickets, crackling fire and distant wolves. Close your eyes and picture it in your mind!

Give the good radio-side journalists something to sink their teeth in to....not just 20-second sound bites about politics, crime and car crashes.

 

[Chuck]

I always wondered why the big news stations (like the one I work for) don't try something like a "long form" news/features channel, using audio only.

I envision something where certain (but not all) news and features, that have some sonic quality to them, be done with full surround sound. Imagine a "recorded live", long-form report, from an outdoor music festival. A re-opening of a historic church or cathedral. An Outdoors segment on white-water rafting, or the sounds of a deer (hunting) camp at night, complete with crickets, crackling fire and distant wolves. Close your eyes and picture it in your mind!

Give the good radio-side journalists something to sink their teeth in to....not just 20-second sound bites about politics, crime and car crashes.

As long as news is all about the sound bite, then this will never happen. The same people who bring you today's radio & TV news also bring you People Magazine. Sadly, that is what passes for new these days. Edward R. Murrow is probably spinning in his grave.

There are notable exceptions, but long-form newscasts are pretty much the domain of NPR, PRI and the BBC. Maybe they will discover a use for this technology.

 

[Mike Walker]

The best place for long-form news programming is, and has been for many years, NPR.

 

[jegrant]

This is a totally underused idea. So many PBS affiliates are attached to and/or co-own NPR affiliates. Why not add digital subchannels on the TV side with either a static screen or some weather radar, along with the audio of each of your radio streams? It would take hardly any bandwidth at all, and would open up a new high quality listening option.

 

[kenglish]

KUER-FM (University of Utah) broadcasts on the channel 9-3 audio of KUEN-DT, owned by the State Board of Regents (and, programmed out of the same facility). It's primary purpose is to feed some "hard to reach" translators, but it's nice to listen to directly.

Too bad they don't add their HD-2 and HD-3 on there. Give 'em some exposure.

 

[Play Freebird]

This is a totally underused idea. So many PBS affiliates are attached to and/or co-own NPR affiliates. Why not add digital subchannels on the TV side with either a static screen or some weather radar, along with the audio of each of your radio streams? It would take hardly any bandwidth at all, and would open up a new high quality listening option.

And DTV "set top boxes" with stereo line output jacks, such as the Zenith DTT901, are available for a few dollars after $40 coupon. Try to find a decent HD tuner at that price.

As others have mentioned, the audio quality of DTV far surpasses the typical 48 k HD Radio "multicast" channel.

 

[jegrant]

This is a totally underused idea. So many PBS affiliates are attached to and/or co-own NPR affiliates. Why not add digital subchannels on the TV side with either a static screen or some weather radar, along with the audio of each of your radio streams? It would take hardly any bandwidth at all, and would open up a new high quality listening option.

And DTV "set top boxes" with stereo line output jacks, such as the Zenith DTT901, are available for a few dollars after $40 coupon. Try to find a decent HD tuner at that price.

As others have mentioned, the audio quality of DTV far surpasses the typical 48 k HD Radio "multicast" channel.

Exactly. Plus, it might be somewhat easier to gain carriage for audio streams on cable systems, if they were bundled with existing TV / video streams. Then, at least some cable companies might just grab the entire bouquet.

 

[MotoMuzak]

Johnathan--

Oregon Public Broadcasting owns an NPR affiliate.....their main station, based in Portland is KOPB-FM on 91.5. OPB rebroadcasts KOPB-FM's audio on their fifth ATSC subchannel (for example, KOPBDT 27.05/10.05 in PDX) but doesn't transmit any video--no static screen or anything. (My Digitalstream box and Pansat both indicate "Audio Only" on 10.05, so I assume the black screen I see is generated inside the receiver.)

They aren't simulcasting their second IBAC channel, KOPBHD2 (an all-music channel titled "OPB Music") on their ATSC channel yet, and I don't know if they ever will or not.......

(Did you read this, tripinva?? ;o)

 

[tripinva]

(Did you read this, tripinva?? ;o)

Sure did! =) Do you know if they're doing the audio for it on the other OPB stations? (KOAC, KEPB, KOAB) Does your receiver tell you the PSIP "call sign"?

Maybe someone should call and ask them to carry "OPB Music". Audio feeds take up virtually no bandwidth on ATSC...

- Trip

 

[MotoMuzak]

It's PSIP'd as "OPBTest". EPG on all my receivers (Panasonic DMREZ27, Pansat 9200HD, Digitalstream box from Rat Shack) displays "OPBTest" as "Regularly Scheduled Programming".

EPG's on the Digitalstream and the Pansat described "OPBTest" as~
"This is a test channel, subject to removal at any time." So apparently OPB must be using this subchannel as an "experimental" DAB channel for the time being.

Less important (but still interesting): there also appears to be a "phantom PSIP" of 10.05 on 10.07, though I have only been able to get that one on my folks' Philips HDTV. It is exactly the same thing as 10.05, so my best guess is it's probably just a seperate PSIP entry that points back to the same physical subchannel.........all three of my receivers seem to ignore 10.07.

I have no idea if any of the other big OPB stations are doing it or not.......OPB is a state-wide network (for the most part anyways) so I imagine they must be.