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Discussion Starter #1
I've been reading up on the various formats used on Blu-Ray discs. I plan on picking up a player soon, but it'll be hooked up to a rather old Sony receiver for a time. Not a big deal to me so long as I can still get the lossy codecs via spdif. I understand that DD+, DTS-HD, and DTS-HDMA contain lossy "cores," and TrueHD discs contain a lossy DD track for backwards compatibility. Seems that all the bases are covered...until I read about uncompressed PCM tracks. I was looking at discs today and noticed that Pirates of the Caribbean uses "Uncompressed 5.1 audio." Do discs like this also contain a lossy track, or will I be stuck with the two-channel decode that the player provides?
 

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Most movies that contain uncompressed PCM tracks also contain a 5.1 DD mix (after all, what's an extra 300MB when you're talking about 25 or 50GB). All of the PotC movies are this way, as well as all of the PCM movie discs that I could think of to look up. However, there are a handful of discs out there that only have PCM tracks, but I think those are mostly limited to concert discs. But yes, if you do end up with one of the PCM-only discs, you'll only get the 2-channel version that the player outputs (SPDIF only has the bandwidth for 2-channel PCM). Most review sites list all of the audio options in a sidebar of some sort when they review a movie. Best to just check a few sites if you have concerns about a specific title.
 

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If your receiver and player feature 5.1 analog connections, then you can get those uncompressed 5.1 tracks in all their lossless glory.
 

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Discussion Starter #4

Quote:
Originally Posted by Pugnax555 /forum/post/14212029


Most movies that contain uncompressed PCM tracks also contain a 5.1 DD mix (after all, what's an extra 300MB when you're talking about 25 or 50GB). All of the PotC movies are this way, as well as all of the PCM movie discs that I could think of to look up. However, there are a handful of discs out there that only have PCM tracks, but I think those are mostly limited to concert discs. But yes, if you do end up with one of the PCM-only discs, you'll only get the 2-channel version that the player outputs (SPDIF only has the bandwidth for 2-channel PCM). Most review sites list all of the audio options in a sidebar of some sort when they review a movie. Best to just check a few sites if you have concerns about a specific title.

Thanks, good to know.


Quote:
Originally Posted by BIslander /forum/post/14212298


If your receiver and player feature 5.1 analog connections, then you can get those uncompressed 5.1 tracks in all their lossless glory.

Yes, it does, but since I intend to buy a new receiver eventually (I could use more inputs), I may as well save a c-note or two on the blu-ray player.
 

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Quote:
Originally Posted by Allnatural /forum/post/14212626


Yes, it does, but since I intend to buy a new receiver eventually (I could use more inputs), I may as well save a c-note or two on the blu-ray player.

I'm not sure what you are referring to there. The PS3 excepted, most Blu-ray players have 5.1 outputs.


While waiting to buy a new receiver, you can use SPDIF for legacy DD and DTS tracks and you can use 5.1 analog connections to get lossless audio from uncompressed 5.1 tracks. No need to settle for stereo or lossy DD/DTS on discs that have 5.1 PCM tracks.


By the way, DD and DTS are encoded at higher bitrates on Blu-ray than you get on DVD. They sound better as a result.
 

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Discussion Starter #6

Quote:
Originally Posted by BIslander /forum/post/14212856


I'm not sure what you are referring to there. The PS3 excepted, most Blu-ray players have 5.1 outputs.

I've got my eye on Sony's forthcoming 350. No analog outs, but it's $100 cheaper than the 550.
 

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Quote:
Originally Posted by Allnatural /forum/post/14216533


I've got my eye on Sony's forthcoming 350. No analog outs, but it's $100 cheaper than the 550.

Yep. That's one of the few without 5.1 or 7.1 analog.
 

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whats the best sounding 5.1 audio format to listen to?


Dolby Digital 5.1

Dolby Pro Logic II

Dolby TrueHD 5.1

Dolby Digital Plus 7.1 (can be downconverted for 5.1)

DTS 5.1

DTS HD 7.1 (downconverted for 5.1)

PCM 5.1


i know im forgetting other 5.1 surround sound formats. i just want to be educated on which is the better audio format that i should be listening to when watching blu-ray movies that have multiple formats.
 

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Quote:
Originally Posted by bolistik /forum/post/15024237


whats the best sounding 5.1 audio format to listen to?


Dolby Digital 5.1

Dolby Pro Logic II

Dolby TrueHD 5.1

Dolby Digital Plus 7.1 (can be downconverted for 5.1)

DTS 5.1

DTS HD 7.1 (downconverted for 5.1)

PCM 5.1


i know im forgetting other 5.1 surround sound formats. i just want to be educated on which is the better audio format that i should be listening to when watching blu-ray movies that have multiple formats.

True HD, DTS HD MA, AND PCM are all lossless formats for blu ray movies, these are the best. Most say in these forums that dts ma is the best due to a higher bit rate but normally the only 2 that will come on the same disc for comparison is true hd and PCM. Check out Spiderman 3 for a comparison between these two.
 

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Discussion Starter #10

Quote:
Originally Posted by jdmac29 /forum/post/15024484


True HD, DTS HD MA, AND PCM are all lossless formats for blu ray movies, these are the best.

Theoretically, PCM is *best* because there's no compression whatsoever, but all three should sound roughly the same.


If your audio equipment is sub-par, you'll probably have a hard time telling apart any of the formats, lossy and lossless.
 

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Uncompressed PCM is a copy of the studio master. TrueHD and dts-MA are lossless compression schemes used to save space on discs. They work like zip files. When decompressed, TrueHD and dts-MA produce the original PCM. As long as the codecs work properly, TrueHD = dts-MA = PCM. The output from all three is identical. It has to be.


DD+ and DTS-HD HRA are high bit rate lossy codecs, better than legacy DD and DTS, but not lossless. They support 7.1 as well. DD+ was used on HD-DVD. But, I don't know that any BDs have DD+ tracks. DD and DTS are the familiar 5.1 formats used on DVD. But, they are usually encoded at higher bit rates on BD. DD maxes out at 448 kbps on DVD, but gets the full 640 kbps on BD. DTS is usually encoded at 754 kbps on DVD and 1.5 mbps on BD. So, the legacy DD and DTS codecs will likely sound better on DVD. (btw, some people say well done lossy encodes are every bit as good as lossless. They maintain the data that is lost in the compression process can not be heard anyway.)


ProLogicII is not an encoding format like the other codecs on your list. It's a digital signal processing tool used to matrix 5.1 from stereo sources. PLIIx adds 7.1 matrixing. DD-EX does 6.1 matrixing. Neo:6 is the DTS version. Those are all DSPs that you can use to alter the sound after it is decoded into PCM. You apply these DSPs yourself in your receiver or pre-pro.

Quote:
Originally Posted by jdmac29 /forum/post/15024484


True HD, DTS HD MA, AND PCM are all lossless formats for blu ray movies, these are the best. Most say in these forums that dts ma is the best due to a higher bit rate but normally the only 2 that will come on the same disc for comparison is true hd and PCM. Check out Spiderman 3 for a comparison between these two.

Lossless codecs use variable bit rates, taking the bandwidth they need at any given moment. Bitrate comparisons are meaningless with lossless. As noted above, dts-MA and TrueHD must be equivalent if both are lossless.

Quote:
Originally Posted by Allnatural /forum/post/15029906


Theoretically, PCM is *best* because there's no compression whatsoever, but all three should sound roughly the same.

Compression affects output when some of the data removed is not restored on decompression. That's what happens with lossy codecs. But, with lossless, all of the data is restored bit for bit. TrueHD and dts-MA are simply zipping techniques. They don't alter the audio in any way. When decoded, both codecs produce the original PCM.
 
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