Blu-ray Dolby Digital vs HS. DDplus...

[tigeraudio2007]

First, we are not arguing. Just stating facts.

Also, it IS necessary to talk about DD and DD+ because TrueHD, DTS Master HD, and LPCM are not available on all titles released. Even the LPCM files are 4306kbps versus TrueHD at 18Mbps. Most HD DVDs only have a DD+ track a 1.5Mbps so it is important to know what connections you need to make and what settings to change on your player and receiver. Do you want Bitstream or PCM? Do you want downmix or not? Etc.

[Gerben Van Duyl]

Originally Posted by Darren

Also, do you know what the bit rate is for DTS on standard DVD? Thanks.

DTS on DVD is either 754 Kb/sec or 1509 Kb/sec, also known as 'half' bit rate and 'full' bit rate DTS. Although DTS would rather you not call it that, as their codec can in fact scale much higher than that. DTS is always a 48/24 payload bit rate or a 96/24 payload when using that extension (core is 48/24, extension contains the extra data for the 96/24 audio).

although DTS is technically a 'lossy' codec, in many instances - when there just isn't all that much audio going on - the DTS encoding is in fact not losing any data at all, as it just isn't getting that heavy of a pay load to encode: in which cases it is in fact lossless...

Regards, G.

[Gerben Van Duyl]

Originally Posted by tigeraudio2007

[...] Even the LPCM files are 4306kbps versus TrueHD at 18Mbps. [...]

Ehh...

How many channels are contained withing that LPCM @ 4306? Stereo on DVD LPCM is 1509kbps, so 4306 would be fine for 5.1, considering that 3 x 1509 = 4527. The LFE channel contains less data, so a 221kpbs smaller stream for the LFE would be fine for a 5.1 original LPCM master file - it doesn't get more lossless than that! (Can someone please validate/falsify my assumption here?)

The DD/THD stream at 18Mbs seems INFLATED as a result - for a 5.1 mix. Why is that? Does it contain the DD, the DD+ and the DD/THD (aka MLP) all at the same time, being redundant three times over at different qualities? Could someone please explain or do the sums?

Thanks, G.

[DaViD Boulet]

First, we are not arguing. Just stating facts.

Also, it IS necessary to talk about DD and DD+ because TrueHD, DTS Master HD, and LPCM are not available on all titles released. Even the LPCM files are 4306kbps versus TrueHD at 18Mbps. Most HD DVDs only have a DD+ track a 1.5Mbps so it is important to know what connections you need to make and what settings to change on your player and receiver. Do you want Bitstream or PCM? Do you want downmix or not? Etc.

Agreed.

But every HD DVD or BD *** SHOULD *** present lossless audio as the first option.

Anything less isn't good enough, regardless of bit-rate and codec combinations. Just go lossless. Disney and Sony have no problem providing lossless on EVERY BD title. Warner, Paramount, and Universal need to learn to prioritize audio as well as video presentation.

[tigeraudio2007]

Sorry, I should clarify. Yes LPCM is lossless. TrueHD has the capability of up to 18Mbps. That is because TrueHD can support more than 8 channels of audio (not that anything is at the level). But technically speaking I believe you could fully represent a 10.2 mix with TrueHD. So, yes LPCM is all you need for a 5.1 mix.

DTS on DVD is a bit confusing. According to DTS, full bitrate if 1509kbps and is scalable to 1344, 1152, 960 or 768. If DTS full bitrate is 1.5Mbps then speaking in terms of binary conversion (1MB = 1,024Kb) then full bitrate for DTS should be 1536kbps, hence why 768kbps is half-bitrate. DTS has no mention of 754kbps, as it is an odd conversion rate. So either DTS miscalculated and 1509 should be 1536 or full-bitrate is not quite 1.5Mbps. I know, trival, but still, it would be nice if there was some standard for it.

[Fred333]

You are right do wish there was a measuring stick of some sort.