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AllStar
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Discussion Starter · #1 ·
I am interested to know if there is any technical reason why Dolby Digital Plus cannot be implemented on DirecTV. Thanks to posts from Darin C and HD AV, I have learned that Dolby Digital Plus is an enhanced version that can offer up to 7.1 channels with improved sound quality. According to the Dolby.com web site, DD+ can offer its full 8 channel potential via the most basic form of HDMI (the 1.3 version is not required). Therefore existing DirecTV receivers would not require a hardware upgrade. Could this audio enhancement be installed via a firmware or software upgrade? I understand Dolby Digital Plus requires a higher bit rate for transmission, but it is backward compatible with the more basic 5.1 audio. That means customers with earlier AV receivers will still enjoy basic 5.1 surround from a Dolby Digital Plus broadcast.

I believe the number of movies with 7.1 audio is on the increase. The following link to Blu-raystats.com can be filtered to show a full list of movies with 7.1 audio.

http://www.blu-raystats.com/Stats/Stats.php

DirecTV has recently shown movies like Hairspray, which is available on Blu-ray disc with DTS 7.1 audio. Could such a movie be broadcast on DirecTV in 7.1 with the use of Dolby Digital Plus? There is also an increasing number of AV receivers that are 7.1 ready, and these are getting more affordable with each new model.

Are there any experts who know the answers? Are there any DirecTV engineers or decision makers reading this thread? If DD+ has already been discussed, would you share with dbstalk members?
 

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Some of the newer Moto cable STBs support DD+ so it wouldn't be to much of a stretch for DirecTV boxes to do it. As for those without DD+ receivers, it would work the same way as the Vudu box does and Blu-ray players do, the STB would have to transcode to DD or decode internally and use analog outputs.

So the real question is could the codec be added to the current DirecTV STBs, I wouldn't be surprised either way.
 

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AllStar
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Discussion Starter · #4 ·
bonscott87 said:
Nobody broadcasts in anything greater then 5.1.

DirecTV receivers can't decode anything greater then 5.1

So while technically they could pass along 7.1 in the broadcast stream nobody actually broadcasts that and even if they did none of the receivers could send anything beyond 5.1 anyway.
I already knew nobody was broadcasting anything greater than 5.1 and I already know the receivers don't presently decode anything greater than 5.1. The purpose of my post is to encourage conversation on what enhancements are possible.
 

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Cutting Edge: ECHELON '09
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It appears the current boxes could decode DD Plus if material is available. I would guess it would be on-demand type material though - as pointed out above it isn't really being broadcasted. I think Europe might be playing around with 5.1+ channels, so there is a chance it could happen here (maybe on premium movie channels ?)

Anyway the question is "if there is any technical reason why Dolby Digital Plus cannot be implemented on DirecTV" - and it certainly appears it is a possibility.

BCM7401 Product Brief

While it is spec'd that the BCM7401 is only HDMI 1.1 all versions of HDMI can carry 8 channels of 24 bit PCM audio at 192kHz - if you let the box do the decoding - or presumably the DD Plus could be sent to an A/V receiver.

BCM7411 Product Brief

The BCM7411 brief is not so clear. It appears it can decode DD Plus - but it is not a 'single chip' solution so there may be other factors involved. If I had to guess - it can probably pass the signal to an A/V receiver and probably can pass decoded PCM on HDMI also.
 

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It is unlikely the HDMI transmitter in the D* boxes can send DD+ over HDMI. It is likely one of the model HDMI transmitters that can only send the same kind of audio over HDMI that it can send over S/PDIF (optical). And DD+ 7.1 cannot be sent over S/PDIF.

The Xbox 360 has the same issue due to the HDMI transmitter used and the hardware design.
 

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bhelton71 said:
It appears the current boxes could decode DD Plus if material is available. I would guess it would be on-demand type material though - as pointed out above it isn't really being broadcasted. I think Europe might be playing around with 5.1+ channels, so there is a chance it could happen here (maybe on premium movie channels ?)

Anyway the question is "if there is any technical reason why Dolby Digital Plus cannot be implemented on DirecTV" - and it certainly appears it is a possibility.

BCM7401 Product Brief

While it is spec'd that the BCM7401 is only HDMI 1.1 all versions of HDMI can carry 8 channels of 24 bit PCM audio at 192kHz - if you let the box do the decoding - or presumably the DD Plus could be sent to an A/V receiver.

BCM7411 Product Brief

The BCM7411 brief is not so clear. It appears it can decode DD Plus - but it is not a 'single chip' solution so there may be other factors involved. If I had to guess - it can probably pass the signal to an A/V receiver and probably can pass decoded PCM on HDMI also.
The 7401 may be able to process DD Plus, IIRC to a max of 13.1, but are the rest of the components built to handle the full capability of the chip?

I'm pretty sure my whole house is not big enough for 13.1 but I could see using 7.1. :rolleyes:

Hmmm....:scratchin

Something to think about.

Mike
 

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The other issue is bandwidth. Bandwidth is already tight and utitized to the max possible amount. DD+ and the other newer "HD Audio" formats use a lot more bandwidth than DD 5.1. This isn't a problem with local Blu-Ray playback, but it's a big, big deal when trying to squeeze transmissions onto a transponder on a satellite.

IMO, bandwidth is the reason why we aren't likely to see anything beyond DD anytime soon.

Besides, I'd bet that the number of DirecTV subscribers with a properly functioning DD 5.1 audio system is under 1%, and 5.1 has been around for more than a decade. The number with a 7.1 system is probably in the hundreds or low thousands, a tiny fraction of the subscriber base.
 

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IIP said:
Besides, I'd bet that the number of DirecTV subscribers with a properly functioning DD 5.1 audio system is under 1%, and 5.1 has been around for more than a decade. The number with a 7.1 system is probably in the hundreds or low thousands, a tiny fraction of the subscriber base.
LOL. It's probably higher then 1% but you're not far off. I'm surprised anytime I go to a friends house and see this big screen HDTV and all the fixens....hooked thru some old stereo system. And they are all proud..."listen this this!!" Yea, sounds great thru those 2 spearkers you got there bud. :rolleyes: I don't have the heart to clue them in.
 

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While I know what you mean, I have run into a lot more terrible-sounding speakers with HTIB 5.1 systems than with 2-speaker stereos. Most HTIB speakers are tiny, and sound squaky and harsh. Naturally, most folks have the bass module cranked up and are impressed by that, and pay little attention to the little speakers.

In my years doing HSP work, I only went to 4 houses that had a "real" surround setup. When done right, it can be fantastic, but most of the time... :eek2:

Oh, and by "properly functioning", I meant "being fed a DD feed". The vast majority of HTIB setups I see are connected via a pair of analog RCAs. I make a point to explain that they need a digital connection (optical/TOSlink on most equipment) to get the DD5.1 surround track to the HT, but most folks ignore me, or just don't understand. Even the ones that already have an optical connection, the guys that I hope know what they are doing, usually disappoint me and turn out to be clueless. It's great to run into the folks who really DO know what HT is all about, except I always end up wasting 30 mins or more talking to them about their HT...
 

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AllStar
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Discussion Starter · #14 ·
IIP said:
While I know what you mean, I have run into a lot more terrible-sounding speakers with HTIB 5.1 systems than with 2-speaker stereos. Most HTIB speakers are tiny, and sound squaky and harsh. Naturally, most folks have the bass module cranked up and are impressed by that, and pay little attention to the little speakers.

In my years doing HSP work, I only went to 4 houses that had a "real" surround setup. When done right, it can be fantastic, but most of the time... :eek2:

Oh, and by "properly functioning", I meant "being fed a DD feed". The vast majority of HTIB setups I see are connected via a pair of analog RCAs. I make a point to explain that they need a digital connection (optical/TOSlink on most equipment) to get the DD5.1 surround track to the HT, but most folks ignore me, or just don't understand. Even the ones that already have an optical connection, the guys that I hope know what they are doing, usually disappoint me and turn out to be clueless. It's great to run into the folks who really DO know what HT is all about, except I always end up wasting 30 mins or more talking to them about their HT...
I am sure you guys are absolutely right. I have an accountant friend whose D* box is connected to his Sony 5.1 amp via a pair of RCA phonos. He insists he gets surround effects already, because the amp shows 'Pro Logic'. It doesn't help that you can pay up to $110 for a optical audio cable at Best Buy (I just looked in their web site). In store demo TVs and 5.1 set ups are often connected by 2 channel RCA and the yellow composite video. I once tried to explain the importance of higher quality to staff at my local BJ's, but I was wasting my breath.:(

Another friend who is an RF engineer, has tiny 5.1 speakers from Radio Shack, connected by bell wire. He has a big smile on his face when he demonstrates his 'home theater system'.

So it seems very few people care about 7.1 audio. Being the original poster of this thread, I am surprised at the number of negative responses (including my own!!!) but I am not discouraged. Like most high end applications, 7.1 audio will not be embraced by the masses. However, I read the attachments from Bhelton71 and I understand one or more current D* receivers have this Broadcom chip that is already capable of DD+ and therefore 7.1 channel audio. Just thinking out loud, but what if the movie comes from the distributor with the original 7.1 channel sound track as an option? Perhaps it could be broadcast intact and the few DD+ 7.1 customers could enjoy the full monty. I wonder if this could be done with relatively small additional cost to DirecTV. I suppose a movie in DTS-HD Master Audio 24 bit 7.1 would have to be watered down to fit on the less capable DD+ 7.1 track, but it would still sound better than basic 5.1.

I'm keeping my fingers crossed that the boffins at DirecTV will look into the possibility of implementing Dolby Digital Plus 7.1 very soon.:)
 

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The Scotsman said:
I am sure you guys are absolutely right. I have an accountant friend whose D* box is connected to his Sony 5.1 amp via a pair of RCA phonos. He insists he gets surround effects already, because the amp shows 'Pro Logic'. It doesn't help that you can pay up to $110 for a optical audio cable at Best Buy (I just looked in their web site). In store demo TVs and 5.1 set ups are often connected by 2 channel RCA and the yellow composite video. I once tried to explain the importance of higher quality to staff at my local BJ's, but I was wasting my breath.:(

Another friend who is an RF engineer, has tiny 5.1 speakers from Radio Shack, connected by bell wire. He has a big smile on his face when he demonstrates his 'home theater system'.

So it seems very few people care about 7.1 audio. Being the original poster of this thread, I am surprised at the number of negative responses (including my own!!!) but I am not discouraged. Like most high end applications, 7.1 audio will not be embraced by the masses. However, I read the attachments from Bhelton71 and I understand one or more current D* receivers have this Broadcom chip that is already capable of DD+ and therefore 7.1 channel audio. Just thinking out loud, but what if the movie comes from the distributor with the original 7.1 channel sound track as an option? Perhaps it could be broadcast intact and the few DD+ 7.1 customers could enjoy the full monty. I wonder if this could be done with relatively small additional cost to DirecTV. I suppose a movie in DTS-HD Master Audio 24 bit 7.1 would have to be watered down to fit on the less capable DD+ 7.1 track, but it would still sound better than basic 5.1.

I'm keeping my fingers crossed that the boffins at DirecTV will look into the possibility of implementing Dolby Digital Plus 7.1 very soon.:)
I think the lesson many have learned with the recent Tivo and 1080p news from DirecTV is never say never. Anything's possible in the future so don't give up hope yet. :)
 

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IIP said:
The other issue is bandwidth. Bandwidth is already tight and utitized to the max possible amount. DD+ and the other newer "HD Audio" formats use a lot more bandwidth than DD 5.1.
Dolby claims that DD+ is more efficient than DD. They say it can do 5.1 in 200kbps. Just because DD+ is capable of huge bitrates doesn't mean it has to be encoded at the max.
 

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AllStar
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Discussion Starter · #17 ·
DarinC said:
Dolby claims that DD+ is more efficient than DD. They say it can do 5.1 in 200kbps. Just because DD+ is capable of huge bitrates doesn't mean it has to be encoded at the max.
Darin, I have just read through a Dolby Digital Plus White Paper from Dolby.com, which supports what you say. On page 7 of the 12 page document, there is a paragraph called 'Unique aspects of Dolby Digital Plus in broadcast formats'. It goes on to say that there new coding tools to enable DD Plus bitstreams that are roughly half the size of basic DD 5.1 bitsreams. If the basic 5.1 is broadcast at 384 Kbps, then you are right on the money with your 200 Kbps number.
That fact alone could remove a major stumbling block in the area of bandwidth constraints.:sure:

Just to pour some cold water on this, the same 12 page White Paper has a table on page 9 that says Dolby Digital Plus bitstream requires HDMI 1.3 version. If that is the case, then we are screwed until DirecTV releases new receivers with HDMI 1.3. :( Since the document was written in 2005, is there any possibility that something has changed? Could DD+ be possible on the existing HDMI 1.1 on current DirecTV receivers? If the answer is no, then possibly the DirecTV set top box could transcode the DD+ 7.1 bitstream to LPCM 7.1, which could indeed be carried by HDMI 1.1.:)
 

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MicroBeta said:
The 7401 may be able to process DD Plus, IIRC to a max of 13.1, but are the rest of the components built to handle the full capability of the chip?

I'm pretty sure my whole house is not big enough for 13.1 but I could see using 7.1. :rolleyes:

Hmmm....:scratchin

Something to think about.

Mike
Damn! Guess I'll put back this 13.1 technology I've been working on.;) :p
 

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Just because DD+ can do 5.1 in 200kbps doesn't mean you want to listen to it. It may sound better than DD at 200kbps, but it can't necessarily work miracles.

It's baffling to me that Dolby has released two new compressions (TrueHD and DD+) and DTS has released at least 2 (Neo6,DTS-HD,DTS-HD MA) in the last two years or so. I'm over all these standards, I'm very ready to go to just PCM out, like we have for two channel. That's how PS3 does its multichannel audio out from BluRay over HDMI (it internally decodes all the formats to PCM, requires HDMI 1.1a or later), it's also how D* boxes have treated 2-channel audio all along over S/PDIF. And this is what everyone should go to. Then every company can have their own proprietary codec on their system without customers having to replace their receiver/amplifier to use it.
 

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AllStar
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Discussion Starter · #20 ·
flipptyfloppity said:
Just because DD+ can do 5.1 in 200kbps doesn't mean you want to listen to it. It may sound better than DD at 200kbps, but it can't necessarily work miracles.

It's baffling to me that Dolby has released two new compressions (TrueHD and DD+) and DTS has released at least 2 (Neo6,DTS-HD,DTS-HD MA) in the last two years or so. I'm over all these standards, I'm very ready to go to just PCM out, like we have for two channel. That's how PS3 does its multichannel audio out from BluRay over HDMI (it internally decodes all the formats to PCM, requires HDMI 1.1a or later), it's also how D* boxes have treated 2-channel audio all along over S/PDIF. And this is what everyone should go to. Then every company can have their own proprietary codec on their system without customers having to replace their receiver/amplifier to use it.
Attention DirecTV - please read this entire thread and speak to your contact at Dolby Laboratories. Your audio technology already works wonders, but we want more. Dolby Digital Plus with 7.1 channels could be your next big thing and it will put you streets ahead of your competitors.
 
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