Linear PCM audio...what the heck is it ?

[Tarheel_]

My Denon DVD-1000 has a few audio options...one for analog or digital and another for "LCPM SELECT ( 96 kHz ---> 48 kHz ) ". The manual says and i quote, "Use this to set the digital audio ouput when playing DVDs recorded in linear PCM audio."

What the heck is it and how do i determine if its recorded in such a format? Thanks!!!

[recoveryone]

My Denon DVD-1000 has a few audio options...one for analog or digital and another for "LCPM SELECT ( 96 kHz ---> 48 kHz ) ". The manual says and i quote, "Use this to set the digital audio ouput when playing DVDs recorded in linear PCM audio."

What the heck is it and how do i determine if its recorded in such a format? Thanks!!!

PCM was a sound format prior to DVD-A and SCAD,it ran into industry support problems. There are a few demo disk( The Ultimate DVD Series) out there that have music tracks with this format its sound good, a bit above normal CD's. Most newer or highend receivers will auto select over to 96khz or 48khz sound processing when playing a disk. Its only a stereo format. My down stairs unit (Pioneer Elite 26TX) plays it in both 96khz & 48khz, but the bedroom unit (Pioneer VSX D309) only plays the 48khz verison. The sound is full and very rich (I haven't heard a DVD-A or SCAD disk yet, but this forum is like sitting in on a studio recording with no mistakes

[Sir Terrence the Terrible]

My Denon DVD-1000 has a few audio options...one for analog or digital and another for "LCPM SELECT ( 96 kHz ---> 48 kHz ) ". The manual says and i quote, "Use this to set the digital audio ouput when playing DVDs recorded in linear PCM audio."

What the heck is it and how do i determine if its recorded in such a format? Thanks!!!

Linear PCM is the basis of a digital audio whether it be Dts, DD, or DVD-A(SACD is not PCM) . Select 96khz option, that way whatever stream is of the highest quality, your DVD player will recognize it and play it. If you choose the 48khz, no matter what sampling rate the audio is(could be 96khz) it will be truncated down to 48khz(not as good as 96khz sampling rate)

CD's are PCM, two channel high sampling high bit rate DVD's are PCM, DVD-A's are PCM.

[recoveryone]

Linear PCM is the basis of a digital audio whether it be Dts, DD, or DVD-A(SACD is not PCM) . Select 96khz option, that way whatever stream is of the highest quality, your DVD player will recognize it and play it. If you choose the 48khz, no matter what sampling rate the audio is(could be 96khz) it will be truncated down to 48khz(not as good as 96khz sampling rate)

CD's are PCM, two channel high sampling high bit rate DVD's are PCM, DVD-A's are PCM.

Hey Terrence, your last statement was a bit confusing, If CD's are PCM format how come they don't play/sound as a PCM disk does?

And when I play a High-bit rate disk (PCM) my receiver clicks over to 96khz, but not with regular CD's. Both playing through DVD player .
I respect your knowledge, but I feel you left me and others in the dark on this one. I understand the setting part on the player, but the difference of CD's, PCM (high bit-rate) CD's.

[Woochifer]

PCM is basically the carrier format used in CD audio and most other uncompressed digital audio formats. There are several varieties of PCM and they vary based on the bit depth and sampling rate. CD audio uses a 16-bit word length and a 44.1 kHz sampling rate.

The DVD format requires the use of EITHER a Dolby Digital or PCM soundtrack. Because DD is a compressed format that can fit a 5.1 soundtrack into one-third of the space required by a two-channel 44.1/16 PCM (CD audio) track, most DVDs use DD as the audio carrier.

However, there are a number of DVDs, mostly with music, that use PCM audio tracks with higher resolution than the 44.1/16 resolution of CDs. Subjectively, this can sound subtlely better than Dolby Digital. The higher resolution can range from bumping up the sampling rate to 48 or 96 kHz or increasing the bit depth from 16 to 20 or 24 bits. Some audiophile labels have issued discs with 96/24 PCM audio tracks, and the sound quality on these discs is superb. The advantage of these discs is that they can be played back on any DVD player and unlike DVD-A or SACD, the signal can be output digitally. Major record labels never got on board with 96/24 discs because it doesn't have the encryption schemes that you see with SACD and DVD-A.

Your Denon DVD player allows for 96/24 resolution audio signals to get passed through the digital outputs. However, some discs with copyright protection do not allow for the audio to get output digitally at a 96 kHz sampling rate and require that the sampling rate step down to 48 kHz before the signal can be sent through the digital outs. Only with a few discs that contain PCM tracks with a 96 kHz sampling rate and copyright restrictions will you ever need to bother with that 96 ----> 48 kHz downconversion option in the DVD setup. On copyright protected discs, the signal output can only use the full 96 kHz sampling rate if it's decoded by the DVD player's internal DACs and output through the analog outputs.

DVD-A is basically a format that plays back PCM tracks encoded at 192/24 (two-channel) or 96/24 (5.1) resolution. The DVD-A tracks are compressed, but during the playback the DVD-A player will restore the data discarded by the compression process prior to the digital-to-analog conversion.

SACD uses a different format from PCM. Rather than sampling multibit words, SACD uses the DSD carrier, which uses one-bit word lengths sampled at very high rates. Supposedly this approximates analog waveforms better, but any valid comparison using SACD won't really happen until we start seeing more recordings done using DSD. Right now, almost all SACDs are converted from analog or PCM sources.

[recoveryone]

Thx Woochifer. You hit the nail on the head

[Tarheel_]

any website that will distinguish these higher PCM recorded DVDs? I'm curious and would like to hear a few.

Thanks everyone !!!

[Woochifer]

any website that will distinguish these higher PCM recorded DVDs? I'm curious and would like to hear a few.

Thanks everyone !!!

Your DVD player will identify if the disc was encoded at a 96 kHz sampling rate or using a 24-bit depth. Some music DVDs identify the resolution on the notes or menus, most don't. Pioneer Artists has a few concert DVDs that have 48/20 or 48/24 resolution PCM tracks in addition to the 5.1 option.

If you want to hear what 96/24 sounds like, Classic Records and Chesky (among others) have produced some excellent high res audio-only DVDs that can play on any DVD player. Chesky's discs require downsampling to 48 kHz for digital output (96 kHz sampling rate only with the analog outs), while Classic's discs are totally open for full resolution digital output.

Keep in mind though that Classic takes a lot of steps in the mastering process that go beyond just doing the transfer at a higher resolution. So, any improvements that you hear might reflect more than just the higher resolution. Even so, they're very much worth sampling. They're currently transitioning their digital products to 192/24 DVD-A, but those new discs will still include a 96/24 track that can doesn't need a DVD-A player to play back. The link to Classic's website is below. Their Blue Note reissues sound incredible as does the Gershwin compilation and their reissue of Alan Parsons Project "I Robot."

http://www.classicrecords.com

[ph0nikat]

to the order of modulating and demodulating... that is where the term "modem" came from.

MOdulate DEModulate

[Monstrous Mike]

The term "linear" in Linear PCM means that each change in bit value represents the same change in the analog amplitude value. So a bit value of say 24 will represent an analog amplitude that is twice that of a bit value of 12. There are various reasons to use something other than linear like Differential PCM or Adaptive Differential PCM but that is another story.

And when you see the term PCM, it usually means Linear PCM.

In strict technical terms Pulse-Code Modulation is a system for transmitting digital data. Modulation is a method of carrying the digital data in an analog wave train. As you may or may not know, you can't just feed 1's and 0's onto a cable and send them on their way. They need to be represented or modulated. Then at the other end of the cable (or over the air or travelling around inside a component) they need to be demodulated.

Pulse code is one of hundreds of ways of modulating/demodulating digital data. It is a fairly simple method which in the binary form simply has pulses and spaces representing the digital bits.

Did you know PCM was invented in 1939! And it was first put to use in telephone transmission systems to have multiple phone links on the same transmission line (time division multiplexing).

Yeh, I guess that's enough for today.

[pixelthis]

Thx Woochifer. You hit the nail on the head

When you use a digital input you are limited by your receivers DACS(you'rs appear quite good)
But the best way to listen to LPCM is through the multichannel out on your player.
The player handles the decoding, etc.
Casino royal is LPCM, you can tell by looking at the box.
USED to see quite a few titles with LPCM , but lately its been more and more DTS MASTER, and DOLBY TRUE HD.
I like LPCM best.

[Nocturno]

OK, so is it ithe case then that if I'm playing a disc with a TrueHD or DTSHD soundtrack, and the amp is displaying Linear PCM, that the player is converting the signal to PCM before it reaches the amp?

[02audionoob]

OK, so is it ithe case then that if I'm playing a disc with a TrueHD or DTSHD soundtrack, and the amp is displaying Linear PCM, that the player is converting the signal to PCM before it reaches the amp?

Wouldn't this just be a case where your movie has a choice of two audio programs and its default is apparently the PCM program? You could go to the movie's menu and change the audio program from 2-channel PCM to the multi-channel choice.

[Sir Terrence the Terrible]

Wooch,

Thanks for turning the light on, sorry I left recoveryone in the dark.

[Feanor]

....

SACD uses a different format from PCM. Rather than sampling multibit words, SACD uses the DSD carrier, which uses one-bit word lengths sampled at very high rates. Supposedly this approximates analog waveforms better, but any valid comparison using SACD won't really happen until we start seeing more recordings done using DSD. Right now, almost all SACDs are converted from analog or PCM sources.

These Wooch observations were made 5 years ago! The plot has only thickened with the advent of Blu-ray.

And today there is a pretty good selection of pure DSD SACDs. Over 1300 according to SA-CD.NET; see here; mostly classical genre as you'd expect.

[pixelthis]

These Wooch observations were made 5 years ago! The plot has only thickened with the advent of Blu-ray.

And today there is a pretty good selection of pure DSD SACDs. Over 1300 according to SA-CD.NET; see here; mostly classical genre as you'd expect.

That is because SACD has received a following in Europe, where most of the newer stuff is coming from, and its mostly classical.
And 1300 titles aint that "great", in fact its a sad statement on a decent format that,
barring a stupid "format" war, might have had a chance.
One hopes that its re-incarnation in Europe is the start of a new life, it would be a worthy
replacement for the turntable.

[Tarheel_]

These Wooch observations were made 5 years ago! The plot has only thickened with the advent of Blu-ray.

think the statements made 5 years ago hold true?

[Sir Terrence the Terrible]

think the statements made 5 years ago hold true?

Had the music industry actually supported these formats, yes it would have held true.

[pweaver1]

I frequently work with outside media sent in for a compilation. The usual ones that I have issues are from the Networks...I usually encounter poor audio, clicks, ticks and taps. When I use AAC output to convert to AppleProRes 422(HQ) Ithe clicks ect are ever present however if I export/convert using Linear PCM I get better quality audio to compose in FCP..why is this?

PCM is basically the carrier format used in CD audio and most other uncompressed digital audio formats. There are several varieties of PCM and they vary based on the bit depth and sampling rate. CD audio uses a 16-bit word length and a 44.1 kHz sampling rate.

The DVD format requires the use of EITHER a Dolby Digital or PCM soundtrack. Because DD is a compressed format that can fit a 5.1 soundtrack into one-third of the space required by a two-channel 44.1/16 PCM (CD audio) track, most DVDs use DD as the audio carrier.

However, there are a number of DVDs, mostly with music, that use PCM audio tracks with higher resolution than the 44.1/16 resolution of CDs. Subjectively, this can sound subtlely better than Dolby Digital. The higher resolution can range from bumping up the sampling rate to 48 or 96 kHz or increasing the bit depth from 16 to 20 or 24 bits. Some audiophile labels have issued discs with 96/24 PCM audio tracks, and the sound quality on these discs is superb. The advantage of these discs is that they can be played back on any DVD player and unlike DVD-A or SACD, the signal can be output digitally. Major record labels never got on board with 96/24 discs because it doesn't have the encryption schemes that you see with SACD and DVD-A.

Your Denon DVD player allows for 96/24 resolution audio signals to get passed through the digital outputs. However, some discs with copyright protection do not allow for the audio to get output digitally at a 96 kHz sampling rate and require that the sampling rate step down to 48 kHz before the signal can be sent through the digital outs. Only with a few discs that contain PCM tracks with a 96 kHz sampling rate and copyright restrictions will you ever need to bother with that 96 ----> 48 kHz downconversion option in the DVD setup. On copyright protected discs, the signal output can only use the full 96 kHz sampling rate if it's decoded by the DVD player's internal DACs and output through the analog outputs.

DVD-A is basically a format that plays back PCM tracks encoded at 192/24 (two-channel) or 96/24 (5.1) resolution. The DVD-A tracks are compressed, but during the playback the DVD-A player will restore the data discarded by the compression process prior to the digital-to-analog conversion.

SACD uses a different format from PCM. Rather than sampling multibit words, SACD uses the DSD carrier, which uses one-bit word lengths sampled at very high rates. Supposedly this approximates analog waveforms better, but any valid comparison using SACD won't really happen until we start seeing more recordings done using DSD. Right now, almost all SACDs are converted from analog or PCM sources.

[Sir Terrence the Terrible]

I frequently work with outside media sent in for a compilation. The usual ones that I have issues are from the Networks...I usually encounter poor audio, clicks, ticks and taps. When I use AAC output to convert to AppleProRes 422(HQ) Ithe clicks ect are ever present however if I export/convert using Linear PCM I get better quality audio to compose in FCP..why is this?

Perhaps it is because you are going from a packet driven audio media, to a bitstream based one. There could also be a filter during encoding to PCM that eliminates or just does not recognize the clicks, pops, and various other audio artifacts.

Without know more detail, it is impossible to tell why the audio artifacts disappear when converting to PCM.

[davey71]

Having had a Marantz sr5002 connected to PS3 for some time I've just bought new Sony STRDG820 (needed extra HDMI's for APPLE TV).

When playing Blu Rays with Tru HD etc or DVDs with DD5.1 the amp display states LCPM and won't switch to display Tru HD, DTS etc.

Likewise Apple TV HD movie downloads with DD - the amp won't switch to display DD - only LCPM

PS3 output set to Linear PCM not bitstream if that matters

Is this a problem or is LPCM the best quality available?

Confused - anyone help?

What are best settings for me?

[L.J.]

Having had a Marantz sr5002 connected to PS3 for some time I've just bought new Sony STRDG820 (needed extra HDMI's for APPLE TV).

When playing Blu Rays with Tru HD etc or DVDs with DD5.1 the amp display states LCPM and won't switch to display Tru HD, DTS etc.

Likewise Apple TV HD movie downloads with DD - the amp won't switch to display DD - only LCPM

PS3 output set to Linear PCM not bitstream if that matters

Is this a problem or is LPCM the best quality available?

Confused - anyone help?

What are best settings for me?

I'm not familiar with that Sony but as long as it's HDMI 1.1 or up your OK. The PS3 cannot bitstream. It decodes the HD audio and sends it as PCM to your AVR. Linear PCM is the correct settings to have on your PS3. So yes, your AVR should display LPCM while using the PS3. Hit display on your PS3 controller(you can hit triangle then display or select) and this will pull up a screen that tells you exactly what the PS3 is outputting.

[jimio11]

[QUOTE=davey71]Having had a Marantz sr5002 connected to PS3 for some time I've just bought new Sony STRDG820 (needed extra HDMI's for APPLE TV).

When playing Blu Rays with Tru HD etc or DVDs with DD5.1 the amp display states LCPM and won't switch to display Tru HD, DTS etc.

Hey did anyone ever answer this question for you cause i have an STRDG920 and i'm having the same issue? Is it normal? or is my BD player not decoding these signals?

[Woochifer]

[QUOTE=jimio11]

Having had a Marantz sr5002 connected to PS3 for some time I've just bought new Sony STRDG820 (needed extra HDMI's for APPLE TV).

When playing Blu Rays with Tru HD etc or DVDs with DD5.1 the amp display states LCPM and won't switch to display Tru HD, DTS etc.

Hey did anyone ever answer this question for you cause i have an STRDG920 and i'm having the same issue? Is it normal? or is my BD player not decoding these signals?

Man, talk about digging into the archives! Tarheel? Monstrous Mike? Those names haven't crossed these paths in quite a while!

Anyway, the simple answer is that the PS3 does not have any internal decoding for Dolby TrueHD and DTS-HD. The PS3 transcodes the audio signals for those formats to PCM and outputs it digitally via HDMI. There should be no difference in the audio quality since all three formats are lossless, with PCM being an uncompressed audio format and the more widely supported format out of the three.

[jimio11]

THANKS. I got the same answer from sony but i thought the guy was BSing me so i could go away