HD audio for broadcast

Posted: Sat Apr 26, 2008 5:10 pm

I think TVpostSound missed what I was saying
and
this is a problem that often happens when we try to talk in some detail as the language and short cut names we give to things can be slightly different in each country

Austalia and England seem to use more similar language and the USA has some slightly different terms
A1, A2, A3 and A4
YES TV is right AES is 2 channels of PCM audio and so each A group is 2 AES streams (4 usable channels of audio)

this does have more info
p://www.tvtechnology.com/features/audio_notes/f_tc_audio_notes-06.25.03.shtml

YES AC3 is an editable stream but not all editor can handle it directly and some use harware to Decode to the more regular PCM audio channels

the reason I brought up the transmittion paths of diferent countries is that any reference to the 5.1 might only confuse

see original post

Quote:

... It's not in surround just stereo - is AES 1/2 3/4 all it needs to be? ...

I tried to keep things in context with the original posters needs and choice of words

BEST advice from all of us has been

Quote:

The post house should have received the delivery specs from the commercial's producer.
.... you need to ask the producer.
etc

TV also talks about the delivery method .. tape etc
you need to ask

HD Audio
some audio heads would consider DSD or 192k@24bit to be HD Audio

Posted: Wed May 14, 2008 10:34 am

So, HD audio is 5.1.....Huh?

I'm not accepting the definition of HD audio as anything over 48K by some audio heads.

Anyone out there want to give the definition of HD audio?
And for Broadcast.... that must be Extra-HD.

Posted: Wed May 14, 2008 11:55 am

I think what the topic has been is Audio for HD rather than HD audio. Just my point of view though.

Posted: Wed May 14, 2008 2:31 pm

Quote:

Anyone out there want to give the definition of HD audio?

Googling HD Audio gets you this:

Microsoft* has chosen Intel HD Audio as the main architecture for their new Unified Audio Architecture* (UAA), which provides one driver that will support all Intel HD Audio controllers and codecs. While the Microsoft driver is expected to support basic Intel HD Audio functions, codec vendors are expected to differentiate their solutions by offering enhanced Intel HD audio solutions. The result is high-quality PC based audio that delivers a seamless convergence of digital entertainment between the PC and consumer electronic devices.

http://www.intel.com/design/chipsets/hdaudio.htm

Posted: Wed May 14, 2008 6:45 pm

hueseph wrote:

I think what the topic has been is Audio for HD rather than HD audio. Just my point of view though.

yes, I think you are right

Audio for HD Video

HD Audio

with HD being used in the same way as Digital was being used years ago

to the golden ears HD digital audio probably means DSD
but many would consider PCM 96K@24bit to be HD and some think it should be PCM 192K@24bit or better

there is the sleeper DVDrom DVDaudio
(or whatever the marketing biy want to call them)
audio formats that are competing for a small portion of the high class retail audio market.

I don't think there is a geniune definition to HD Audio at the moment

side note
MIDI
Musical Instrument Digital Interface as it is known now
but originally it was
Musical Instrument DATA Interface

the marketing people seem to get a hold of a word and run with it
for the past decade or two it has been Digital
today
it is HD High Definition
late 80's HD video was quite different to what it is now
back then frame rate was king but now pixel resolution and lines seem to be in
1080i and 1080p with 25 or 30 depending on country and power

anyway, whatever

Intel writing a spec for HD Audio seems ... Evil or Very Mad

what were we talking about
Cool

Posted: Wed May 14, 2008 7:06 pm

Exactly!

Intel apparently decided it was in their best interests to (TM) the phrase.

Thought it was a fun side note...

Laughing

Posted: Wed May 14, 2008 7:30 pm

yeah
and to trade mark a commonly used word or phrase is
aaarrrggghhh !!
happens too often

now we will never have a definition for HDaudio
Smile

Posted: Thu May 15, 2008 1:13 am

Hand me a Kleenex...

Posted: Thu May 15, 2008 6:33 am

I still haven't seen a complete, concise answer to the original question. (And "I" sure don't know either!) And, if I'm reading it right, the question applies to audio being matched with an HD video, in this case a commercial for broadcast TV? There surely must be a standard of delevery shaping up out there....

When in doubt, I would supply the best specs you can serve up in a 16/48 stereo wav file. (24/48 might be ok, but it might be too big an assuminption to think everything in the chain can play it?)

If it's gotta be in surround, you could also do it in AC3, or Dobly ProLogic II, which is used all the time in broadcasts that go out to SD and HD clients over the same cable delivery system.

Depending on the type of surround content, ProLogic II is ok, as long as you dont' get too crazy with effects, panning, etc. It is also editable as a stand-alone stereo wav file, should you have to do any work on it after the encoding process.

I had a long chat with a Dolby rep at an AES show a few years back, and he was explaining to me how meta-data works (much of it lost on me, sorry to say!) but in theory, everything is 'tagged' with digital info as it comes down the pipe, and assuming broadcasters have their standards sorted out, the broadcast equipment at the transmission end should detect what it's being fed. (Which is partly why and how the "Dolby 5.1" beacon comes on when a show is being shown in 5.1, and then goes out during the commericals, when the content is "only" in stereo.)

I'd love to know exactly what is needed, too, but until further notice, I think you have to ask around about what's required, case by case. Even then, you may face as much confusion and misunderstanding as anywhere else.... Rolling Eyes

Posted: Thu May 15, 2008 6:49 am

My understanding of "HD" radio is that it is compressed at something on the order of 100 KB/Sec - it is nothing that could be considered "High Definition", rather it's more like "Hyped Digital".

CD-Quality for cloth ears and car stereos. I doubt the requirements are any different than any other radio medium.

I don't KNOW any of this, but I've seen basically the same information in a few different places - one of which is Wikipedia.

Posted: Thu May 15, 2008 2:44 pm

JoeH wrote:

I still haven't seen a complete, concise answer to the original question. (And "I" sure don't know either!)
There surely must be a standard of delevery shaping up out there....

we did
ask your broadcaster their requirements

failing that
stereo pcm on 1 and 2
AC2 on 3 and 4
D-ProLogicII could probably go on either pair
remember that your program needs to be compatable with the SD side of things as well. The Broadcaster could be delivering the content from their HD server
but also and their SD and Analog services

that's close to the standard that is shaping up
however with mp4 getting out there more and more and internet delivery getting stronger the
Free To Air broadcasters on mp2 may have to lobby thier governments to think again

on a minor note Dolby is not the only surround sound method out their

so
some may chose to deliver with 5 individual channels
... I feel this could be a problem as the Ingest Department of the Broadcaster may not realise and anything could happen

as Joe said .... the meta-data ... get the right tagging.

sorry I can't leave it their
Standards are all very well but some Broadcaster may choose to do their own thing anyway
In my country a broadcaster may ingest an Advert as stereo ... even though it was produced in 5.1.
Confused

hopefully the stereo compatability works
and
many are still watching on a small mono portable shaping up TV anyway

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