Where's the multichannel LPCM?

[rarredoa]

Sony and Disney movies used to release their movies in multichannel PCM along with lossy Dolby Digital. I am realizing that most new releases are now in TrueHD, and of course FOX and Universal is doing this in DTS-HD MA. I used to prefer the LPCM because my HTPC would play these lossless formats without the downsampling that most of the blu-ray software players are known to do. I realize that in theory there should be no audible difference betwee DTS Dolby and LPCM lossless codecs. But if there is downsampling with the proprietary codecs, then I'm not getting all the audio, the way the director intended for us to hear.

My question is... is LPCM done with? I was under the impression that there was more than enough space for a 7.1 LPCM track on a blu-ray disc

[bkbluray]

Originally Posted by rarredoa

Sony and Disney movies used to release their movies in multichannel PCM along with lossy Dolby Digital. I am realizing that most new releases are now in TrueHD, and of course FOX and Universal is doing this in DTS-HD MA. I used to prefer the LPCM because my HTPC would play these lossless formats without the downsampling that most of the blu-ray software players are known to do. I realize that in theory there should be no audible difference betwee DTS Dolby and LPCM lossless codecs. But if there is downsampling with the proprietary codecs, then I'm not getting all the audio, the way the director intended for us to hear.

My question is... is LPCM done with? I was under the impression that there was more than enough space for a 7.1 LPCM track on a blu-ray disc

To answer your question, yes and no. It's probably not completely done with, but studios can save a lot of space on a disc by releasing them with Dolby TrueHD or DTS-HD instead of PCM. Originally most Blu-rays were in PCM because most players at the time could only handle that as a lossless codec. Now, you have the PS3 as well as many other Blu-ray players are capable of decoding Dolby TrueHD as well as DTS-HD. So, short version, they do it to save space, but you're NOT going to lose quality, since the only thing that is compressed on these is the dead space, not the actual sound.

[rarredoa]

Originally Posted by bkbluray

To answer your question, yes and no. It's probably not completely done with, but studios can save a lot of space on a disc by releasing them with Dolby TrueHD or DTS-HD instead of PCM. Originally most Blu-rays were in PCM because most players at the time could only handle that as a lossless codec. Now, you have the PS3 as well as many other Blu-ray players are capable of decoding Dolby TrueHD as well as DTS-HD. So, short version, they do it to save space, but you're NOT going to lose quality, since the only thing that is compressed on these is the dead space, not the actual sound.

Will FUTURE releases feature ONLY DTS-HD and TrueHD? I understand that u won't lose any of the original recording with TrueHD and DTS-HD, but in my case, using PowerDVD, I actually DO lose because of the downsampling that the player does before converting to PCM. My understanding is that the sound gets downsampled to 48 kHz/16 bit. I understand that True HD and MasterAudio are higher than that.

I could use my PS3 which does everything now, but my HTPC sounds better. Dunno why, better D/A converters in sound card maybe. I use analog outs from PC to multichannel analog-in to my receiver. Another drawback in using my PS3... that fan is just way too noisy!

[LembasBread]

Originally Posted by rarredoa

But if there is downsampling with the proprietary codecs, then I'm not getting all the audio, the way the director intended for us to hear.

I'm not sure you understand what downsampling is. Taking a 24/96 audio track and changing it to 16/48 on the output would be downsampling.

Are you worried that Dolby TrueHD and DTS-HD MA are not truly lossless? According to Dolby and DTS's specs they are mathematically identical to the uncompressed masters they are compressed from. If they were not, they would be liable for false advertisement. Lossless audio compression has been around for a while now so it's not a difficult thing to code/decode.

As for the waning of LPCM tracks, I miss them, too. Studios seem to be making marketing deals with Dolby and DTS, especially New Line and Fox. They have deals that result in them using DTS exclusively on their releases. Also, more studios are starting to want to add more special features on discs or use Bonus View which requires more bandwidth for video and secondary audio.

My philosophy has always been if there's no need to compress it, then don't. These discs have plenty of room for five star hi-bitrate video along with 24/48 5.1 audio. There really is no excuse not to use it for any material that is 16/48 or 24/48. Now I will start advocating lossless compression when the bit-depth and sample rate or number of channels start to rise. I don't mind 24/96 Dolby TrueHD or 7.1 24/48 DTS-HD MA because I know that otherwise the uncompressed forms of those would be ridiculously bandwidth heavy.

[rarredoa]

Originally Posted by LembasBread

I'm not sure you understand what downsampling is. Taking a 24/96 audio track and changing it to 16/48 on the output would be downsampling.

Are you worried that Dolby TrueHD and DTS-HD MA are not truly lossless? According to Dolby and DTS's specs they are mathematically identical to the uncompressed masters they are compressed from. If they were not, they would be liable for false advertisement. Lossless audio compression has been around for a while now so it's not a difficult thing to code/decode.

As for the waning of LPCM tracks, I miss them, too. Studios seem to be making marketing deals with Dolby and DTS, especially New Line and Fox. They have deals that result in them using DTS exclusively on their releases. Also, more studios are starting to want to add more special features on discs or use Bonus View which requires more bandwidth for video and secondary audio.

My philosophy has always been if there's no need to compress it, then don't. These discs have plenty of room for five star hi-bitrate video along with 24/48 5.1 audio. There really is no excuse not to use it for any material that is 16/48 or 24/48. Now I will start advocating lossless compression when the bit-depth and sample rate or number of channels start to rise. I don't mind 24/96 Dolby TrueHD or 7.1 24/48 DTS-HD MA because I know that otherwise the uncompressed forms of those would be ridiculously bandwidth heavy.

Guess i should have been more clear, but i meant downsampling as going from24/96 and changing it to 16/48

[LembasBread]

Originally Posted by rarredoa

My understanding is that the sound gets downsampled to 48 kHz/16 bit.

All feature films are usually 24/48 when compressed with TrueHD/DTS MA. So downsampling to 16-bit would suck and there really isn't anyway to know. Some concert discs are 96khz though. The easy way to check that is to connect HDMI to the receiver and check the sampling rate from there.

It's entirely possible that the converters in the sound card suck ass. Though 24-bit to 16-bit downrezzing won't be too much of a concern because even the most sophisticated DAC's can't resolve anything deeper than about 20-bit. Anything below that humans can't even hear and even machine noise is louder than what's down in those bits.

[Lucy Diamond]

OP - I hear ya. I prefer the PCM. I like the way my multi-channel analog breaks it up.

I think, since we are hearing more and more news about Blu 500, we will probably see it again.

For me right now, it is simply a matter of "Do I play this movie in my player or my PS3" once that issue is resolved in a few months, I don't know that I'll miss it.

I honestly don't think PCM is done with.

[Clark Kent]

I prefer PCM as well since it is compatible with the widest range of equipment and you know the soundtrack hasn't been altered or tinkered with. But the major studios have all but abandoned it on new releases. I think there are several factors for this. One was space saving on both total capacity and bandwidth. The studios want to put more gimmicks like BD-Live on BDs.

Another serious factor rarely mentioned is that people can rip the audio right off the discs. Virtually everyone in the world has the tools able to manipulate straight PCM data, whereas Dolby's and DTS's compression schemes add another layer of security to the audio data with few having access to decoding tools for them. Why buy the soundtrack to the movie if you can rip it directly off the disc? Another reason is that the studios firmly believe that the familiar brands of Dolby and DTS also help to sell discs to customers. Most dvd owners have never seen a dvd with a PCM soundtrack.

[Big Daddy]

Originally Posted by rarredoa

Will FUTURE releases feature ONLY DTS-HD and TrueHD? I understand that u won't lose any of the original recording with TrueHD and DTS-HD, but in my case, using PowerDVD, I actually DO lose because of the downsampling that the player does before converting to PCM. My understanding is that the sound gets downsampled to 48 kHz/16 bit. I understand that True HD and MasterAudio are higher than that.

I could use my PS3 which does everything now, but my HTPC sounds better. Dunno why, better D/A converters in sound card maybe. I use analog outs from PC to multichannel analog-in to my receiver. Another drawback in using my PS3... that fan is just way too noisy!

Read this article about PowerDVD and downsampling. The problem is not with Dolby TureHD and DTS HD, but rather with copy protection, the limitations of sound cards, and Windows PC (Microsoft). According to this article Cyberlink admits that there may be a bug in their program that downsamples HD audio.

http://www.bit-tech.net/news/2007/10...ng_explained/1

To answer your other question about LPCM, it is estimated that a 2 hour movie with a 16-bit, 5.1 soundtrack requires 4.14GB with LPCM versus 1.26GB for either TrueHD or DTS HD.

[saprano]

1gig to 4gigs? i thought HD audio took up around 10gigs?

and yea OP i like PCM also, i wish alot more movies used it. at least we still have disney that likes to use it.

[prerich]

Originally Posted by Big Daddy

Read this article about PowerDVD and downsampling. The problem is not with Dolby TureHD and DTS HD, but rather with copy protection, the limitations of sound cards, and Windows PC (Microsoft). According to this article Cyberlink admits that there may be a bug in their program that downsamples HD audio.

http://www.bit-tech.net/news/2007/10...ng_explained/1

To answer your other question about LPCM, it is estimated that a 2 hour movie with a 16-bit, 5.1 soundtrack requires 4.14GB with LPCM versus 1.26GB for either TrueHD or DTS HD.

Alot has changed since that article was written. TMT doesn't downsample, any program that does downsample can be re-upsampled by Windows Vista (192khz/24 bits PCM using an Onkyo 605 has been verified on AVS forum), and as rumor mill may have it - the Asus Xonar HDAV 1.3 goes on sale August 22, 2008 - $179.00 for the base model and $202.00 for the daughter card with 7.1 analog outs (the $179 version only has hdmi) and provides a PAP.

[dobyblue]

Originally Posted by rarredoa

Guess i should have been more clear, but i meant downsampling as going from24/96 and changing it to 16/48

If your system does this it's a fault of your system, not the codecs.

[rarredoa]

Originally Posted by dobyblue

If your system does this it's a fault of your system, not the codecs.

To clarify, I never said it was a fault of the codecs. I was simply stating that in my case because of my software fault, I can only get lossless audio via PC if the tracks are LPCM

[prerich]

Originally Posted by rarredoa

To clarify, I never said it was a fault of the codecs. I was simply stating that in my case because of my software fault, I can only get lossless audio via PC if the tracks are LPCM

Not true, you still get lossless - they've just been downsampled. The bitrate is still way higher than that of DTS, AC3 or DTS Core (if you have TMT or PowerDVD - WinDVD9 is doing the DTS Core on DTS-HD-MSTR Tracks but correctly decodes TrueHD). If its straight LPCM - you don't need a PAP, but for TrueHD or DTS-HD-MSTR you need the PAP for no downsampling. Like I've said before however - If you have Vista and a good audio card you can upsample it back to 48khz/24bits or even higher.

[rarredoa]

Originally Posted by prerich

Not true, you still get lossless - they've just been downsampled. The bitrate is still way higher than that of DTS, AC3 or DTS Core (if you have TMT or PowerDVD - WinDVD9 is doing the DTS Core on DTS-HD-MSTR Tracks but correctly decodes TrueHD). If its straight LPCM - you don't need a PAP, but for TrueHD or DTS-HD-MSTR you need the PAP for no downsampling. Like I've said before however - If you have Vista and a good audio card you can upsample it back to 48khz/24bits or even higher.

Can it be called lossless if it is downsampled? What was PAP, again? I like to think i have a good sound card, but no VISTA.

[prerich]

Originally Posted by rarredoa

Can it be called lossless if it is downsampled? What was PAP, again? I like to think i have a good sound card, but no VISTA.

Technically you are correct, if its downsampled and you are not getting the exact bit count - but its still not compressed lossy - Bit count and information is way to high to be lossy. So what do we call downsampled 48khz/24 bits - to 48khz/16 bits...the 1080i of sound? You are getting lossless if the track was mastered in 48khz/16 bits no real downsampling here. PAP is Protected Audio Path, with the Xonar and Azuntech cards you will be able to have a protected audio path that AACS requires. On the Xonar card you will have it even using th 7.1 analog inputs on the daughter card (no need for HDMI if you don't have a HDMI receiver yet). You have an X-Fi if I'm not mistaken - good card for now - but you can't upsample unless you have Vista - Vista did get some audio things right such as there special settings in the Advanced properties - you can set the default bit rate and that's how it will output sound as. Can't go into detail but XP is kinda weak on the audio side compared to Vista.

[rarredoa]

Originally Posted by prerich

Technically you are correct, if its downsampled and you are not getting the exact bit count - but its still not compressed lossy - Bit count and information is way to high to be lossy. So what do we call downsampled 48khz/24 bits - to 48khz/16 bits...the 1080i of sound? You are getting lossless if the track was mastered in 48khz/16 bits no real downsampling here. PAP is Protected Audio Path, with the Xonar and Azuntech cards you will be able to have a protected audio path that AACS requires. On the Xonar card you will have it even using th 7.1 analog inputs on the daughter card (no need for HDMI if you don't have a HDMI receiver yet). You have an X-Fi if I'm not mistaken - good card for now - but you can't upsample unless you have Vista - Vista did get some audio things right such as there special settings in the Advanced properties - you can set the default bit rate and that's how it will output sound as. Can't go into detail but XP is kinda weak on the audio side compared to Vista.

Can't go into detail?... I love details, especially audio details!... I'm out of HDMI inputs on my receiver... So if/when i can get rid of my x-fi to upgrade to one of these newer enhanced audio cards, i guess i'll have to put up with the "1080i" of HD sound. Realistically though, i wonder how much different 24 bit sound is to 16 bit sound, given the limitations of, what i call, my mid-fi equipment. Happy with my setup though, nonetheless, just not perfect.

[prerich]

Originally Posted by rarredoa

Can't go into detail?... I love details, especially audio details!... I'm out of HDMI inputs on my receiver... So if/when i can get rid of my x-fi to upgrade to one of these newer enhanced audio cards, i guess i'll have to put up with the "1080i" of HD sound. Realistically though, i wonder how much different 24 bit sound is to 16 bit sound, given the limitations of, what i call, my mid-fi equipment. Happy with my setup though, nonetheless, just not perfect.

You're just fine Rarredoa There's more to good sound than 48khz/24 bits - I would put your system up against other people who are capable of 48khz/24 but have lesser speakers. The whole system comes into play. I'm picking up a Xonar as soon as they are available.