What happened to PCM? - Blu-ray Forum

Stlsports · 05-11-2009, 02:09 PM

I haven't seen a major movie that includes a PCM soundtrack in a long time. Has something happened? Are they just using Dolby TrueHD and DTS-HD now?

jurassic_pork · 05-11-2009, 02:13 PM

from what I read here on the forum by the audio experts is that PCM takes too much space on the disc so studios have been option for other track types to save room for additional content etc....

Another_Dude · 05-11-2009, 02:15 PM

Dolby TrueHD and DTS-HD give you the same thing using less space on the disc.

Its a good thing.

Kyo28 · 05-11-2009, 02:21 PM

Quote:

Originally Posted by Another_Dude

Dolby TrueHD and DTS-HD give you the same thing using less space on the disc.

Its a good thing.

Exactly. These codecs offer the same lossless quality, but require less space. That space can be used to increase video quality or add extra features, I would think.

VinnAY · 05-11-2009, 02:27 PM

Quote:

Originally Posted by Another_Dude

Dolby TrueHD and DTS-HD give you the same thing using less space on the disc.

Its a good thing.

so what you're saying is that what's marketed a "lossless" or "full bandwith"...is a lie?

MOONPHASE · 05-11-2009, 02:33 PM

Quote:

Originally Posted by VinnAY

so what you're saying is that what's marketed a "lossless" or "full bandwith"...is a lie?

Dolby TrueHD is still considered as lossless

cjones235 · 05-11-2009, 03:07 PM

Quote:

Originally Posted by MOONPHASE

Dolby TrueHD is still considered as lossless

Actually I consider DTS Master Audio lossless. But i consider Dolby TrueHD to be just dolby digital that had a sex change and was made up to look like lossless audio.

ryoohki · 05-11-2009, 04:24 PM

Quote:

Originally Posted by cjones235

Actually I consider DTS Master Audio lossless. But i consider Dolby TrueHD to be just dolby digital that had a sex change and was made up to look like lossless audio.

Well it's not.. it's just a zipped container with a PCM file inside. I mean i love RAR on PC, but if the file is Zipped in a zip container i'll still download it because in contain the documents in it. Might not be as efficient but once extracted both are the same. Off course if you decode it and the software is wrong (like not giving you the DCOMP option on TrueHD) than it's a software problem.. By default, this option is set to AUTO (whenever you decode inside a AVR or not) and like DD (DD offer only ON/OFF), you should disable it. Many players that decode TrueHD don't offer that option and you and up not knowing exactly what it does.

The thing is, most people think louder is better quality. Most DTS track are louder by 4BD.

Personally i prefer DTS HD, because it offer people without HD audio a 1.5mbits DTS track....

kefrank · 05-11-2009, 02:36 PM

Quote:

Originally Posted by VinnAY

so what you're saying is that what's marketed a "lossless" or "full bandwith"...is a lie?

What? No. Dolby TrueHD and DTS-HD MA are both lossless audio codecs. The word "lossless" doesn't really apply to PCM, because it's a qualifier for compression and PCM is uncompressed. I'm not sure what you're suggesting is a lie.

andyman1970 · 05-11-2009, 02:39 PM

Quote:

Originally Posted by kefrank

What? No. Dolby TrueHD and DTS-HD MA are both lossless audio codecs. The word "lossless" doesn't really apply to PCM, because it's a qualifier for compression and PCM is uncompressed. I'm not sure what you're suggesting is a lie.

That and the fact the Dolby TrueHD and DTS HD-MA sound better.

DeadDog · 05-11-2009, 03:34 PM

Quote:

Originally Posted by andyman1970

That and the fact the Dolby TrueHD and DTS HD-MA sound better.

I think that's open for debate, however threads seem to always get closed once that debate get's started

.

I personally like PCM better and would like to see it being used more. I understand stand the whole compressed lossless fact behind TrueHD and DTS HD-MA but if the extra space isn't being used for anything else, then why not include the PCM track. I know it's been done before, 300 has both PCM and TrueHD. (in which case PCM sounds significantly better on my system, to my ears anyway)

Anyway, I always think the more options the better. PCM could just become another "bonus" or "extra feature" on some discs.

Yeha-Noha · 05-11-2009, 04:52 PM

Quote:

Originally Posted by andyman1970

That and the fact the Dolby TrueHD and DTS HD-MA sound better.

One reason people believe this myth is because decompressed lossless tracks sometimes sound louder than the original PCM track. However, once decompressed to PCM how can it sound better? People are fooled into thinking such because of the volume level. If it is higher, then it will usually sound better because the listener can discern more subtle details in the sound.

However, if the original PCM track is played back at the same level as the decompressed lossless track (which is also PCM), then there will be no difference in the sound. PCM can't sound better than PCM. It is pure digital audio and has to be PCM before the DACs in your AVR or player, whichever you prefer, can convert the digital (PCM) to analog audio.

PCM (Master Audio) = PCM (uncompressed) = DD TrueHD or DTS-HD:MA = PCM (uncompressed). PCM = PCM. QED.

demiscy · 05-11-2009, 02:41 PM

I constantly see PCM 2.0 on concert BDs if that makes you feel any better

Stlsports · 05-11-2009, 02:50 PM

I don't really care what it is as long as it sounds good.

SkillzthatKillz · 05-11-2009, 02:52 PM

"lossless" audio means that the audio track is of the same quality as the studio master track...so True HD and DTS HD-MA are both lossless codecs (just like PCM) that require less space

Another_Dude · 05-11-2009, 02:54 PM

Quote:

Originally Posted by VinnAY

so what you're saying is that what's marketed a "lossless" or "full bandwith"...is a lie?

No. The data can be compressed and uncompressed with losing any of the information.

PCM - Lossless and uncompressed

DTHD/DTSHDMA - Lossless, compressed then uncompressed.

dialog_gvf · 05-12-2009, 05:32 PM

Quote:

Originally Posted by Another_Dude

Dolby TrueHD and DTS-HD give you the same thing using less space on the disc.

Its a good thing.

As long as the Dialog Normalization (DN) of DTHD is not used. Otherwise it won't be bit equivalent to the LPCM.

Gary

kefrank · 05-12-2009, 05:42 PM

Quote:

Originally Posted by dialog_gvf

As long as the Dialog Normalization (DN) of DTHD is not used. Otherwise it won't be bit equivalent to the LPCM.

Gary

Dialnorm does not affect the mix in any way. It only affects the starting volume level, meaning you might have to adjust the volume on your receiver to level-match a TrueHD track with dialnorm metadata and a LPCM track. The audio is still identical.

Yeha-Noha · 05-12-2009, 07:27 PM

Quote:

Originally Posted by kefrank

Dialnorm does not affect the mix in any way. It only affects the starting volume level, meaning you might have to adjust the volume on your receiver to level-match a TrueHD track with dialnorm metadata and a LPCM track. The audio is still identical.

That's correct. Dialnorm has no effect on the sound quality at all.

I wonder, perhaps dialog_gvf was thinking about DRC. DD-TrueHD does have it but it is easily turned off in the player or receiver. Then it won't be any different than uncompress PCM. But if DRC is left on, that might be the reason for some claiming that DD-TrueHD sounds inferior to dts-HD:MA or LPCM.

kingofgrills · 05-12-2009, 10:31 PM

This is an excellent topic, as long as things remain on track, and here's an excellent article that was written to address uncompressed audio versus lossless audio codecs:

http://www.highdefdigest.com/news/show/1233

I highly encourage you to read it carefully. Even if you are comparing tracks for the same film, such as uncompressed PCM and Dolby TrueHD, you might still find variances due to the bit resolution used to master the tracks. When everything is equal during the mastering process, the following is true:

uncompressed PCM = Dolby TrueHD = DTS-HD MA

When mastered equally, each format presents the exact same set of 0's and 1's to render the soundtrack.

05-11-2009, 02:09 PM	#1
Stlsports Active Member Member since:Feb 2008	What happened to PCM? I haven't seen a major movie that includes a PCM soundtrack in a long time. Has something happened? Are they just using Dolby TrueHD and DTS-HD now?

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05-11-2009, 02:13 PM	#2
jurassic_pork Blu-ray Samurai Member since:Dec 2007 Blu-ray reviews:4 Trading Score:240	from what I read here on the forum by the audio experts is that PCM takes too much space on the disc so studios have been option for other track types to save room for additional content etc....

05-11-2009, 02:15 PM	#3
Another_Dude Blu-ray Guru Member since:Dec 2008 Blu-ray collection:191 Blu-ray reviews:8	Dolby TrueHD and DTS-HD give you the same thing using less space on the disc. Its a good thing.

05-11-2009, 02:41 PM	#13
demiscy Blu-ray Guru Member since:Sep 2007 Location:Nicosia, CY (EU) Blu-ray reviews:2 Trading Score:31	I constantly see PCM 2.0 on concert BDs if that makes you feel any better

05-11-2009, 02:50 PM	#14
Stlsports Active Member Member since:Feb 2008	I don't really care what it is as long as it sounds good.

05-11-2009, 02:52 PM	#15
SkillzthatKillz Special Member Member since:Feb 2008 Location:Cincinnati, OH Blu-ray collection:214 DVD collection:2 Trading Score:1	"lossless" audio means that the audio track is of the same quality as the studio master track...so True HD and DTS HD-MA are both lossless codecs (just like PCM) that require less space

05-12-2009, 10:31 PM	#20
kingofgrills Blu-ray Guru Top ranked HT gallery Member since:Dec 2007 Location:PDX Home Theater Gallery:31 4K collection:5 Blu-ray collection:81 Trading Score:31	This is an excellent topic, as long as things remain on track, and here's an excellent article that was written to address uncompressed audio versus lossless audio codecs: http://www.highdefdigest.com/news/show/1233 I highly encourage you to read it carefully. Even if you are comparing tracks for the same film, such as uncompressed PCM and Dolby TrueHD, you might still find variances due to the bit resolution used to master the tracks. When everything is equal during the mastering process, the following is true: uncompressed PCM = Dolby TrueHD = DTS-HD MA When mastered equally, each format presents the exact same set of 0's and 1's to render the soundtrack.

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