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.
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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.
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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.