Linear PCM the same as DD TrueHD?? - Blu-ray Forum

Red Pill 101 · 07-10-2009, 04:08 PM

Hello everyone,

I just got a STR-DA2400es Sony receiver. It seems to be decoding everything correctly. However, certain older titles advertise on the box standard Dolby Digital (not TrueHD), and PCM uncompressed 5.1.

The movie in question is Underworld
https://www.blu-ray.com/movies/movies.php?id=498

My receiver reads it as Linear PCM 5.1. Is this the same/better/worse than TrueHD?

The receiver decodes movies listed as having TrueHD as such, and likewise if they have DTS-MA. It's only with slightly older titles like Underworld and Underworld Evolution: If I select the PCM audio track the receiver decodes it as Linear 5.1.

Any info is appreciated--thank you.

Another_Dude · 07-10-2009, 04:12 PM

PCM 5.1 is lossless just like (or VERY similar too) Dolby True HD and DTS HD-MA. It is better sound that DD 5.1.

un4gvn94538 · 07-10-2009, 04:14 PM

Quote:

Originally Posted by Red Pill 101

Hello everyone,

I just got a STR-DA2400es Sony receiver. It seems to be decoding everything correctly. However, certain older titles advertise on the box standard Dolby Digital (not TrueHD), and PCM uncompressed 5.1.

The movie in question is Underworld
https://www.blu-ray.com/movies/movies.php?id=498

My receiver reads it as Linear PCM 5.1. Is this the same/better/worse than TrueHD?

The receiver decodes movies listed as having TrueHD as such, and likewise if they have DTS-MA. It's only with slightly older titles like Underworld and Underworld Evolution: If I select the PCM audio track the receiver decodes it as Linear 5.1.

Any info is appreciated--thank you.

explaination here: https://forum.blu-ray.com/showthread.php?t=41820

doctorD · 07-10-2009, 05:26 PM

Some would say they prefer PCM over TrueHD, but they are both Lossless. The chart in the link of the post above does show that LPCM can handle a higher bit rate over TrueHD. Some great example movies for PCM are the early Sony or Disney releases.

threefiftyrocket · 07-10-2009, 05:31 PM

With the right decoders, they will all sound the same. Linear PCM however, is not only Lossless, it is completely uncompressed, and cannot be transferred in 5.1 over TosLink, like you can bitstream the other two. So you can only experience Linear PCM 5.1 if you run HDMI to your receiver. They will all sound the same tho

Red Pill 101 · 07-10-2009, 06:06 PM

Thank you all very much for the responses. The hyperlink was especially helpful!

cembros · 07-10-2009, 06:06 PM

well technically PCM isnt lossless as lossless referes to a form of compression. PCM is the uncompressed master while true hd and dtshdma are a lossless compression, but yes, pcm=dtshdma=truehd.

threefiftyrocket · 07-10-2009, 06:09 PM

Quote:

Originally Posted by cembros

well technically PCM isnt lossless as lossless referes to a form of compression. PCM is the uncompressed master while true hd and dtshdma are a lossless compression, but yes, pcm=dtshdma=truehd.

You said exactly what I meant, much more eloquently I might add... this is what I was going for... kachow

zicmubleu · 07-10-2009, 07:00 PM

Quote:

Originally Posted by cembros

well technically PCM isnt lossless as lossless referes to a form of compression. PCM is the uncompressed master while true hd and dtshdma are a lossless compression, but yes, pcm=dtshdma=truehd.

So is there any timing correction or distortion provided by the AVR for dtshdma and truehd? If you had better codecs in your AVR than your player's PCM decoder could it be possible to have a better quality using bitstream files than the PCM of the player?

dolphinc · 07-10-2009, 07:17 PM

I read an article or a post somewhere that PCM and Dolby HD are still compressed on some level and DTS-HD is really the only uncompressed format and also has the highest bit rate. Is this true and would it explain why sony is kicking the idea around to drop Dolby HD for DTS-HD?

Please, these are questions not statements as I am still learning the whole audio game.

sapiendut · 07-10-2009, 07:27 PM

Quote:

Originally Posted by dolphinc

I read an article or a post somewhere that PCM and Dolby HD are still compressed on some level and DTS-HD is really the only uncompressed format and also has the highest bit rate. Is this true and would it explain why sony is kicking the idea around to drop Dolby HD for DTS-HD?

Please, these are questions not statements as I am still learning the whole audio game.

During my studio days, all masters were done in PCM. So if PCM master is compressed, I wonder how DTS-HD got their masters from

threefiftyrocket · 07-10-2009, 07:34 PM

Quote:

Originally Posted by dolphinc

I read an article or a post somewhere that PCM and Dolby HD are still compressed on some level and DTS-HD is really the only uncompressed format and also has the highest bit rate. Is this true and would it explain why sony is kicking the idea around to drop Dolby HD for DTS-HD?

Please, these are questions not statements as I am still learning the whole audio game.

No, PCM is the truly uncompressed format... no compression at all, thats why it has to travel over HDMI for true 5.1, only HDMI has enough bandwidth capabilities... True HD and DTS MA can bitstream over TosLink, they are LOSSLESS codecs, but still compressed.

dolphinc · 07-10-2009, 07:37 PM

Quote:

Originally Posted by threefiftyrocket

No, PCM is the truly uncompressed format... no compression at all, thats why it has to travel over HDMI for true 5.1, only HDMI has enough bandwidth capabilities... True HD and DTS MA can bitstream over TosLink, they are LOSSLESS codecs, but still compressed.

Then why the 3 formats? I never understood why manufactures cannot just standardize 1 format and make it less confusing for the consumers.

sapiendut · 07-10-2009, 07:38 PM

Quote:

Originally Posted by dolphinc

Then why the 3 formats? I never understood why manufactures cannot just standardize 1 format and make it less confusing for the consumers.

PCM takes the most space
Dolby TrueHD is used so Dolby receives $$ from royalties
DTS-HD MA is used so DTS receives $$ from royalties

It's aaaall about the $$

dolphinc · 07-10-2009, 07:46 PM

Quote:

Originally Posted by sapiendut

PCM takes the most space
Dolby TrueHD is used so Dolby receives $$ from royalties
DTS-HD MA is used so DTS receives $$ from royalties

It's aaaall about the $$

Yeah and that sucks a$$.

sapiendut · 07-10-2009, 07:48 PM

Quote:

Originally Posted by dolphinc

Yeah and that sucks a$$.

Yup! With all that space, they should just use PCM and that's it. No TrueHD DTS-MA confusion, cheaper receivers and BD player cost of manufacturing and R&D.

cembros · 07-10-2009, 08:08 PM

Quote:

Originally Posted by threefiftyrocket

No, PCM is the truly uncompressed format... no compression at all, thats why it has to travel over HDMI for true 5.1, only HDMI has enough bandwidth capabilities... True HD and DTS MA can bitstream over TosLink, they are LOSSLESS codecs, but still compressed.

not true hd and dtshdma cannot bitstream over toslink, only hdmi

threefiftyrocket · 07-10-2009, 09:39 PM

Quote:

Originally Posted by cembros

not true hd and dtshdma cannot bitstream over toslink, only hdmi

you are correct my friend, shame on me for taking someones word for this as knowledge, and not doing the research myself...

BIslander · 07-11-2009, 01:12 AM

The movie soundtrack is recorded as multichannel PCM, which takes up a lot of space. Studios would rather conserve space for more extras and such. So, they use TrueHD and dts-MA to losslessly compress the PCM. Both codecs are really just types of zip files. The decoder unzips them, producing the same PCM that was fed into the encoder in the first place.

PCM = decoded TrueHD = decoded dts-MA.

The audio quality is the same because the PCM is identical in all three cases.

07-10-2009, 04:08 PM	#1
Red Pill 101 Expert Member Top contributor Member since:Jun 2009 Location:PA Home Theater Gallery:35 Blu-ray collection:702	Linear PCM the same as DD TrueHD?? Hello everyone, I just got a STR-DA2400es Sony receiver. It seems to be decoding everything correctly. However, certain older titles advertise on the box standard Dolby Digital (not TrueHD), and PCM uncompressed 5.1. The movie in question is Underworld https://www.blu-ray.com/movies/movies.php?id=498 My receiver reads it as Linear PCM 5.1. Is this the same/better/worse than TrueHD? The receiver decodes movies listed as having TrueHD as such, and likewise if they have DTS-MA. It's only with slightly older titles like Underworld and Underworld Evolution: If I select the PCM audio track the receiver decodes it as Linear 5.1. Any info is appreciated--thank you.

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07-10-2009, 04:12 PM	#2
Another_Dude Blu-ray Guru Member since:Dec 2008 Blu-ray collection:191 Blu-ray reviews:8	PCM 5.1 is lossless just like (or VERY similar too) Dolby True HD and DTS HD-MA. It is better sound that DD 5.1.

07-10-2009, 05:26 PM	#4
doctorD Blu-ray Ninja Member since:Jun 2007 Location:Redmond, WA Home Theater Gallery:47 4K collection:397 Blu-ray collection:1723 Blu-ray reviews: 12 Trading Score:1	Some would say they prefer PCM over TrueHD, but they are both Lossless. The chart in the link of the post above does show that LPCM can handle a higher bit rate over TrueHD. Some great example movies for PCM are the early Sony or Disney releases.

07-10-2009, 05:31 PM	#5
threefiftyrocket Blu-ray Guru Member since:Apr 2009 Location:Carmel, IN Blu-ray collection:478 Blu-ray reviews:1 Trading Score:3	With the right decoders, they will all sound the same. Linear PCM however, is not only Lossless, it is completely uncompressed, and cannot be transferred in 5.1 over TosLink, like you can bitstream the other two. So you can only experience Linear PCM 5.1 if you run HDMI to your receiver. They will all sound the same tho

07-10-2009, 06:06 PM	#6
Red Pill 101 Expert Member Top contributor Member since:Jun 2009 Location:PA Home Theater Gallery:35 Blu-ray collection:702	Thank you all very much for the responses. The hyperlink was especially helpful!

07-10-2009, 06:06 PM	#7
cembros Power Member Member since:Jan 2008 Blu-ray collection:456 Trading Score:4	well technically PCM isnt lossless as lossless referes to a form of compression. PCM is the uncompressed master while true hd and dtshdma are a lossless compression, but yes, pcm=dtshdma=truehd.

07-10-2009, 07:17 PM	#10
dolphinc Power Member Member since:May 2009 Location:Florida	I read an article or a post somewhere that PCM and Dolby HD are still compressed on some level and DTS-HD is really the only uncompressed format and also has the highest bit rate. Is this true and would it explain why sony is kicking the idea around to drop Dolby HD for DTS-HD? Please, these are questions not statements as I am still learning the whole audio game.

07-11-2009, 01:12 AM	#19
BIslander Blu-ray Samurai Member since:Sep 2008 Location:Bainbridge Island, WA	The movie soundtrack is recorded as multichannel PCM, which takes up a lot of space. Studios would rather conserve space for more extras and such. So, they use TrueHD and dts-MA to losslessly compress the PCM. Both codecs are really just types of zip files. The decoder unzips them, producing the same PCM that was fed into the encoder in the first place. PCM = decoded TrueHD = decoded dts-MA. The audio quality is the same because the PCM is identical in all three cases.

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