Panasonic BD60 & BD80 Secondary Audio Bit Rates

[discking]

BD60 & BD80 Secondary Audio Bit Rates

Does anyone know what the bitrate output of down sampled DTS-HD MA and Dolby TrueHD is when using bitstream output via S/PDIF on the Panasonic BD60/80?

In other words, are DTS and Dolby lossless tracks down sampled to 1509 kbit/s and 640 kbit/s, respectively when using a 48k digital sound connection?

[callas01]

I don't know what the bit rates are but in order to use the secondary audio and still get lossless audio (i believe at 48 kHz) you need to have the players audio set to PCM so you maintain the lossless audio. Otherwise by setting it to bitstream you will get the lossy track when using secondary audio, and I am pretty sure that will be in 48 kHz also, but won't that also depend on the recording of the Blu-ray also, if it was recorded in 48 or 96 khz?

[BIslander]

You get whatever bitrate was used during encoding.

The DTS core is usually encoded at 1509 and that's what you usually get. But, there are a small number of releases with lower bitrate cores.

The same goes for the companion DD 5.1 tracks included in the TrueHD package. They are usually encoded at 640. But, if a lower rate was used, that's what you'll get over S/PDIF.

btw, the term "secondary audio" has a particular meaning on Blu-ray. It's additional audio that gets mixed with the main sound track - audio for PIP commentaries and menu sounds. It's confusing to use the term "secondary audio" when discussing how lossless audio is bitstreamed over S/PDIF.

[callas01]

Originally Posted by BIslander

You get whatever bitrate was used during encoding.

The DTS core is usually encoded at 1509 and that's what you usually get. But, there are a small number of releases with lower bitrate cores.

The same goes for the companion DD 5.1 tracks included in the TrueHD package. They are usually encoded at 640. But, if a lower rate was used, that's what you'll get over S/PDIF.

btw, the term "secondary audio" has a particular meaning on Blu-ray. It's additional audio that gets mixed with the main sound track - audio for PIP commentaries and menu sounds. It's confusing to use the term "secondary audio" when discussing how lossless audio is bitstreamed over S/PDIF.

that is what I thought he meant.... thanks for stepping in... figured you would be around soon... BDP Guru.

[discking]

Originally Posted by BIslander

You get whatever bitrate was used during encoding.

The DTS core is usually encoded at 1509 and that's what you usually get. But, there are a small number of releases with lower bitrate cores.

The same goes for the companion DD 5.1 tracks included in the TrueHD package. They are usually encoded at 640. But, if a lower rate was used, that's what you'll get over S/PDIF.

btw, the term "secondary audio" has a particular meaning on Blu-ray. It's additional audio that gets mixed with the main sound track - audio for PIP commentaries and menu sounds. It's confusing to use the term "secondary audio" when discussing how lossless audio is bitstreamed over S/PDIF.

Thanks for the good info.

Seeing as both standard DTS and DD are thought to be effectively, not literally, "transparent" at their max encoding rates it might seem that using the S/PDIF audio interface is not quite the crisis it could seem to be for an "average" installation -- absolute sound types can argue over the finite fractional differences and what sort of feed grass their power cables were fed on and the orientation of the receiver to the true north or just magnetic north.

As for "secondary", that's Panasonic's term for distinguishing between lossless or core audio streams, not mine. This business about how you only get the lossless stream if you have "secondary audio" "off", but get the core lossy stream if you have "secondary audio" "on" is a peculiar way of expressing it in a user interface.

I agree that the term, as used by Panasonic, is a little hard to figure out until you get that they are talking about "secondary" as meaning streaming the "core" lossy component via digital as opposed to, I guess, the "primary" or loss less stream. Kind of confusing.

[BIslander]

Originally Posted by discking

Thanks for the good info.

Seeing as both standard DTS and DD are thought to be effectively, not literally, "transparent" at their max encoding rates it might seem that using the S/PDIF audio interface is not quite the crisis it could seem to be for an "average" installation -- absolute sound types can argue over the finite fractional differences and what sort of feed grass their power cables were fed on and the orientation of the receiver to the true north or just magnetic north.

The max bitrate legacy codecs sound great.

As for "secondary", that's Panasonic's term for distinguishing between lossless or core audio streams, not mine. This business about how you only get the lossless stream if you have "secondary audio" "off", but get the core lossy stream if you have "secondary audio" "on" is a peculiar way of expressing it in a user interface.

I agree that the term, as used by Panasonic, is a little hard to figure out until you get that they are talking about "secondary" as meaning streaming the "core" lossy component via digital as opposed to, I guess, the "primary" or loss less stream. Kind of confusing.

I think you are mistaken there. The Panasonic manuals use the term Secondary Audio in the proper context - refering to audio that is not part of the main soundtrack that gets mixed with the audio from the main soundtrack. When Secondary Audio is turned on, the player decodes a lossy track instead of the lossless one. Perhaps that's the source of your confusion about the term.

[discking]

Originally Posted by BIslander

The max bitrate legacy codecs sound great.

I think you are mistaken there. The Panasonic manuals use the term Secondary Audio in the proper context - refering to audio that is not part of the main soundtrack that gets mixed with the audio from the main soundtrack. When Secondary Audio is turned on, the player decodes a lossy track instead of the lossless one. Perhaps that's the source of your confusion about the term.

I think we're in agreement, but I may not have expressed my take very well.

The term secondary, as used by Panasonic would, at first, seem to indicate a secondary, different content stream. As they intend it, it is still somewhat non-intuitive, as what's really being said is not "primary" versus "secondary" but, instead, "core" versus "integrated".

I wish they would use those words instead because both DTS-HD and DTHD use core lossy streams with pre-compression lossless elements that can either be combined with the core, to form a lossless high bit rate stream, or be discarded, leaving the original lossy core. Now, maybe what I just said is off, but that's the way I have read the explanations.

In any case, it's just terminology. But it would have been nice if they had chosen a slightly more accurate set of English language names for what they are talking about.

[BIslander]

Originally Posted by discking

The term secondary, as used by Panasonic would, at first, seem to indicate a secondary, different content stream. As they intend it, it is still somewhat non-intuitive, as what's really being said is not "primary" versus "secondary" but, instead, "core" versus "integrated".

Manuals often torture words and concepts in an effort to make things understandable to the uninitiated. But, the term "secondary audio" is unambiguous and it is not misused in the Panasonic BD80 manual. Secondary Audio refers to audio which is not part of the main soundtrack that must be mixed in by the player in order to be heard.

Both DTS-HD and DTHD use core lossy streams with pre-compression lossless elements that can either be combined with the core, to form a lossless high bit rate stream, or be discarded, leaving the original lossy core. Now, maybe what I just said is off, but that's the way I have read the explanations.

That is correct with DTS, but not with TrueHD. DTS uses a lossy 5.1 core and builds HD HRA and lossless Master Audio outputs by adding extension data to the core. TrueHD does not have a lossy core. The Dolby core is a lossless two channel downmix of the multichannel PCM source. The Dolby extensions add the data needed for 5.1 and 7.1. Each phase is lossless. The DD 5.1 output over optical is a separate track included in the TrueHD package solely for that purpose.

In any case, it's just terminology.

I suppose. But, you'll notice the first response to your post did not answer the question you were asking. That happened because you used the words Secondary Audio in the title even though the question had nothing to do with Secondary Audio.

The BD80 Audio D/A Converter runs at 192kHz/24bit
same for the B60

[discking]

Originally Posted by BIslander

I suppose. But, you'll notice the first response to your post did not answer the question you were asking. That happened because you used the words Secondary Audio in the title even though the question had nothing to do with Secondary Audio.

As usual, I have learned more from listening to people who know a subject than from listening to myself talk about what I think I know.

It would be fair to say that, whatever the interface or explanatory issues are, that Panasonic engineers did not consult anyone at Apple about how to present these options to the user...

[BIslander]

Originally Posted by discking

It would be fair to say that, whatever the interface or explanatory issues are, that Panasonic engineers did not consult anyone at Apple about how to present these options to the user...

Yep.