Metadata in the Home: A Case History
Alert readers will recall that I've been struggling to understand the use of metadata, particularly dailnorm, in TV broadcasting. This month I thought I'd share with you my adventures with it to date.
Parts of my experience are typical for consumers, others are not. They may all serve, however, to shed some light on our current difficulties with the system, particularly the audio in the system. It is useful for us "in the biz" to know how we are or are not perceived by our audiences.
I've been informally observing the quality of the audio and video in the television broadcast system as an end user, trying to get a sense of how well the whole system works for the typical viewer. In spite of lucking into a way better than average TV (that I probably would never have bought on my own), I haven't made any particular effort to optimize my viewing situation, except as explorations for various articles for TV Technology.
ON THE COUCH WITH DAVE
(click thumbnail)Dave's couch potato setup.As mentioned, I am blessed with a Really Good TV, a 32-inch Bang & Olufsen BeoVision Avant. Said television has HD component video inputs, two RF inputs, VCR, DVD, satellite, set-top box and auxiliary inputs, plus an output to feed a VCR, as well as a variety of control inputs. S-Video is available on all inputs. Digital and analog audio is available on all inputs. The TV supports surround sound, with DIN jacks to feed B&O-powered speakers (naturally).
Meanwhile, the internal stereo speakers are equivalent to a good consumer audio system. Whew! You get the idea.
Feeding this Danish Dream, I have (a) "digital" cable TV service, (b) a cheap stereo VCR, and (c) a cheap DVD player-pretty typical middle-class couch potato fare. I do take pride in knowing how to program my VCR!
So here's my experience with all this.
FROM MY CABLE PROVIDER
I signed up for digital cable service from my local provider, Charter Communications, late in 2002. They sent a technician over who installed a set-top box and hooked it up. He also left me a user handbook and a glossy four-color card showing all the channels I could get. The installation he did was minimal-he connected the RF output of the set-top box to the RF input of the VCR and the RF output of the VCR to one of the two RF inputs of TV, complimented me on the nice picture and good sound quality then left.
When I read the user handbook, it said that "Your Charter technician will completely set up and explain the operation of your system when it is initially installed."
In the general settings section of the user handbook, there was a mention of Dolby Digital Sound, with an explanation of three possible settings for what they called Audio Range; these were "wide, " "normal" and "narrow." Further, it mentioned setting options for the Digital Output: "Dolby Digital" or "other."
I have not seen a difference in performance between these two settings, when viewing/listening to a digital channel. All the explanations were minimal and did not refer directly to any metadata functions (although, admittedly, the audio-range settings almost certainly have been relabeled dynamic range controls).
WHAT S-A SAID
When I started poking around the set-top box, I discovered it was a Scientific-Atlanta Explorer 3100. As Scientific-Atlanta had provided no written materials, I went online and managed to download a manual for my particular unit. The manual was quite terse, consisting primarily of hookup diagrams. The one diagram that coincided with what Charter did for me was on Page 19; "Connecting A Non-Stereo TV and A Non-Stereo VCR." The only discussion of audio occurred on Page 29 under "Tips for Improved Performance," which included half-a-dozen suggestions about what to do if there was no sound.
I did find a brief discussion of the behavior of the digital and analog audio outputs on a product FAQ, including an inferred insight that, ah, not all of my cable signals were, ah, in fact, ah, digital, as the, er, advertisements from Charter, um, promised!
WHAT B&O SAID
Bang & Olufsen included a reference book and a guide for the Avant, which provided a good deal of setup and operational info. There was no mention of metadata or the implications of hooking up to an RF input vs. line or digital inputs. Bass, treble, balance and loudness compensation were all mentioned, plus set-up routines for surround installations. No specifications were given.
Interestingly, when I hooked everything up for optimum performance, which included in my case S-Video, line-level audio and digital audio, the TV wouldn't switch automatically between analog and digital channels. Once it detected a digital audio signal, it wouldn't revert to analog except by cycling to standby and back, which really cut into my channel surfing. I have a query into B&O as to why this should be so, but no answer yet. In the meantime, I can't use the digital signal.
WHAT DOES IT ALL MEAN?
The reason I dragged you through all of this is to make an important point, and to illustrate the plight of the end-user. At present, there is no reasonable chance that an end-user is going to be able to make use of metadata in a viable way. At the end point of the chain, none of the vendors even acknowledged the existence of metadata, much less provided any guidance about how to configured the television to use, (except for Charter's Audio Range instructions).
In my case, the vendor hooked up the set-top box in the worst possible configuration as the default hookup. There was no discussion or consideration of any other possibilities.
When we double back to what Dolby envisioned for metadata, we find there is a cognitive disconnect here. Dolby's "Guide to Metadata" states, "The consumer's Dolby Digital decoder processes the metadata stream according to parameters set by the program creator, as well as certain settings for bass management and dynamic range that are chosen by the consumer to reflect his or her specific... conditions." [snip] "This control, however, requires the producer to correctly set the metadata parameters because they affect important aspects of the audio-and can seriously compromise the final product if set improperly. Although most metadata parameters are transparent to consumers, certain parameters affect the output of a home decoder..."
As things stand now, we (the audio support group for the content creators) are not yet consistently setting the right metadata values. Worse, the service providers at the end of the chain are withholding the information needed by consumers to have even a chance of using this system satisfactorily.
Consider this: I am an experienced audio engineer with a deep background in both audio systems and audio education. I am on good speaking terms with the folks at Dolby and the folks at B&O. I possess decent instrumentation and the knowledge of how to use it. For all that, I can't get my system to work as advertised! I humbly suggest to you that if under these hothouse privileged conditions the system doesn't work, it can't possibly work for the consumers for whom it was intended.
WE'VE GOT WORK TO DO!
Next month, I plan to actually measure all this for your amusement and edification. Hopefully, I'll also be able to establish a viable dialogue with both Scientific-Atlanta and Charter Communications. I'll report to you on how that goes.
Thanks for listening.
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By Frank Miller