Guest jonlee Posted June 5, 2007 Posted June 5, 2007 A bit confused over all the new formats. Blu-ray : DTS-MA, LPCM, DTS and DD (in decending order of SQ). HD-DVD : TrueHD, DD+, DTS and DD (in decending order of SQ) Is LPCM also available on HD-DVD? Is LPCM available on all blu-ray? Where to check which audio format which HD/BR has as Amazon does not seems to indicate this info. If rank all of them in decending order, are they supposed to be as follows (at least on spec)? 1. DTS-MA (lossless) 2. TureHD (lossless) 3. LPCM (lossless) 4. DTS-HR 5. DD+ 6. DTS 7. DD (note : order updated)
kzone Posted June 5, 2007 Posted June 5, 2007 can also share on what is needed / how to be able to enjoy each of those format?
Guest jonlee Posted June 5, 2007 Posted June 5, 2007 Did some research. DTS-HD-MA Blu-ray : 24.5 Mbit/s HD-DVD : 18 Mbit/s DD TrueHD Max : 18 Mbit/s (max) 5 Mbit/s (typical) LPCM 6.144 Mbit/s (max) DTS-HD-HR Blu-ray : 6 Mbit/s HD-DVD : 3 Mbit/s DD+ HD-DVD : 3 Mbit/s Blu-ray : 1.7 Mbit/s DTS HD-DVD : 1.5 Mbps Blu-ray : 1.5 Mbps DVD : 1.5 Mbps (max) 768kbps (typical) DD Blu-ray : 640 kbps HD-DVD : 504 kbps DVD : 480 kbps Seems like all format can exist in both HD-DVD and Blu-ray. However, typical implementation currently : HD-DVD : TrueHD @ 5 Mbit/s Blu-ray : LPCM @ 6.144 Mbit/s Above correct?
c7221624705751 Posted June 5, 2007 Posted June 5, 2007 Let me try: 1) LPCM is not available in HDDVD because it doesn't have enough capacity. (one of the favorite "strong points" when u argue for BR) 2) no LPCM is not necessarily available on all BR (for example Terminator 2 has only DD). How to check ? right now no way, have to wait for the 1st review. sites like dvdtalk are gd place to check out. 3) DD+ is like a HD-DVD exclusive since it's specifically designed to overcome HD-DVD's storage limitation. (something abt block size HDDVD doesn't allow 16bit words etc). BluRay doesn't have this limitation so no need to DD+. A DD full rate in BluRay is as good as a DD+. So I won't rate DD+ anywhere higher DD automatically. 4) DTS has one more called "DTS-HD HR" which is lossy but better than DTS core. A decoder for "DTS-HD MA" does not automatically mean it can decode "DTS-HD HR", and vice versa. 5) Now how abt DTS-HD MA/TruHD compared with LPCM ? ... well they are supposed to be equal. But real life example had been mixed. Ppl had compared "The Departed" which has LPCM in BluRay and TruHD in HD-DVD, and some claim LPCM is better.
karlie Posted June 5, 2007 Posted June 5, 2007 Actually the lossless compression formats should be better quality than LPCM: since there is average a factor 2 of compression, the lossless can increase the number of bits, or sampling frequency or channels for the same cost as LPCM. Ppl had compared "The Departed" which has LPCM in BluRay and TruHD in HD-DVD, and some claim LPCM is better. Which just shows that once more we will be facing differences in mixes.
Doggie Howser Posted June 5, 2007 Posted June 5, 2007 A bit confused over all the new formats. Blu-ray : LPCM, DTS-MA, DTS and DD (in decending order of SQ). HD-DVD : TrueHD, DD+, DTS and DD (in decending order of SQ) Is LPCM also available on HD-DVD? Is LPCM available on all blu-ray? Where to check which audio format which HD/BR has as Amazon does not seems to indicate this info. If rank all of them in decending order, are they supposed to be as follows (at least on spec)? 1. LPCM (lossless) 2. DTS-MA (lossless) 3. TureHD (lossless) 4. DD+ 5. DTS 6. DD LPCM doesn't really need a decoder. I am not sure if HD DVD supports it, but the idea behind Dolby TrueHD and DTS MA is that they don't need LPCM, especially since HD DVD standard requires all HD DVD players to have built in TrueHD (as well as DD+) decoders. Also LPCM requires more storage space. HD DVDs can use VC1/AVC + TrueHD so can fit on HD30/15 sized discs. The truth is that I don't think anyone (not in the industry) has heard DTS HD MA in a home environment to date. There are no BR players with DTS HD MA decoders to day. And while there are some HDMI 1.3 AV receivers with DTS HD MA decoders, there is no way currently to get a DTS HD MA bitstream over HDMI to those receivers. Which kinda sucks. To answer the question posed by kzone: With HD DVD players today, you can enjoy DD TrueHD and DD+ formats today with either analog 5+.1 connections or HDMI 1.x AV amplifiers (TrueHD or DD+ decoded to LPCM sent out over HDMI) With BR players, it is a tad more complicated. Not an issue with uncompressed PCM aka LPCM etc since they are just passed through HDMI to any HDMI 1.x AV receiver. But there are no players with DTS HD MA decoders today and no way to send bitstream DTS HD MA out (part of HDMI 1.3 player spec but is not mandatory feature) to receiver over HDMI. But so far, only Fox BRs use DTS HD MA. Hope the HDMI 1.3 BR players will get a firmware upgrade to support the HD MA bitstream or better yet, the PS3 will get another firmware upgrade to unlock this feature.
c7221624705751 Posted June 5, 2007 Posted June 5, 2007 Actually the lossless compression formats should be better quality than LPCM: since there is average a factor 2 of compression, the lossless can increase the number of bits, or sampling frequency or channels for the same cost as LPCM. Let's be academic and agree with you, yes, it can. ;) however, if the source track is the same, it won't be any different. Studios won't take out a diff sound mix just to do a TruHD release. It will use the same track, convert to LPCM, then publish in BluRay as it is, and compress it to TruHD for HD-DVD.
Doggie Howser Posted June 5, 2007 Posted June 5, 2007 Actually I thought DD+ was because of a limitation of TrueHD. You can't "extract" core DD from TrueHD whereas DTS HD MA has the DTS core embedded inside, so you always needed a basic DD or DD+ to complement TrueHD. That said, the DD+ decoder is a standard requirement on HD DVD players. Not so with BR players I think. Not all BR discs have 1.5Mbps DD+. I think a number are just 640kbps even when the HD DVD version supports DD+
Guest francis woo Posted June 5, 2007 Posted June 5, 2007 Phew, very cheem ah!! With all these complicated audio codecs flying around, I think better look for a good tube amp to enjoy stereo nirvana... :)
armoury Posted June 5, 2007 Posted June 5, 2007 Phew, very cheem ah!! With all these complicated audio codecs flying around, I think better look for a good tube amp to enjoy stereo nirvana... :) Gotta agree, quite confusing. I will just add that it's possible for there to be a DD 640kbps track on SD DVD -- the Pink Floyd Pulse DVD has it, just that since 640kbps is not part of the DVD spec, your DVD player might not be able to decode it, or even pass through the bitstream. E.g. my Pioneer 969 can't do either, but when I hooked up my laptop and passed out the bitstream, my Marantz SR8200 (firmware upgraded to 8300 spec) was able to decode and playback the 640 kbps bitstream.
kzone Posted June 5, 2007 Posted June 5, 2007 Guys, very informative thread we have here. R we gonna have a HD planet soon? This should be one of the sticky...
SiriuslyCold Posted June 5, 2007 Posted June 5, 2007 all digital audio is in PCM (lets forget about SACD/DSD for awhile) for a CD - the specs is fixed at 2 channels of 16b/44.1kHz each for a movie, you can go up to 8 channels of 24b/192kHz (or 24b/96Khz, or 24b/48kHz) obviously there is no space on a regular DVD to fit in all the audio, so they compress it using DD or DTS, and sometimes have a 2ch 24/48 PCM track (some concert/music DVDs) if there is more space, as on a BD disc, you can probably put the whole 8 channels of 24/192 PCM in native form - no need decoders... all DACs handle PCM up to 24/192 for some time now If there is less space, you need to use some form of compression. To preserve quality, use Lossless compression - like MLP - which is being used for TrueHD. You need a decoder for this but the result of the decoding is the original 8 channels of 24/192 PCM as karlie said - if the source of the audio was 24/192 and (lossless) compressed it could sound better than a 24/48 PCM, but I think you will need a highly resolving system to make out the differences. there's an interesting discussion on SH.tv forums about bit depth (16b, 24b) vs sampling freq (48kHz, 96kHz, 192Khz) and the effect on sound quality
karlie Posted June 6, 2007 Posted June 6, 2007 When I started working on Dolby Digital Decoder (back in 96) I could easily make the difference between 48kHz 16bit and 48kHz 18bit (the source being 24bit). I don't think this is true anymore after suffering 11years of air-conditioning noise.
Guest jonlee Posted June 6, 2007 Posted June 6, 2007 For those using xa2 and coaxial digital out pcm, is the pcm output a discrete 5.1 pcm? Realise using coaxial pcm out, my lexicon is able to apply logic 7 to the incoming 48kHz pcm signal, but the volume is very very soft. I had to up the volume by 20dB to make it comparable to typical dvd watching level. Also, when u switch audio using the audio button on the remote control, how to know which sound track it is currently playing? I can hear some difference, but there is no osd display to indicate what audio track is selected. As incoming are all pcm, there is no change to the lexicon display also.
Doggie Howser Posted June 6, 2007 Posted June 6, 2007 For those using xa2 and coaxial digital out pcm, is the pcm output a discrete 5.1 pcm? Coax does not support discrete MPCM. Only stereo PCM or Dolby or DTS encoded multichaneel.
Guest tonytakitani Posted June 6, 2007 Posted June 6, 2007 Is LPCM available on all blu-ray? Where to check which audio format which HD/BR has as Amazon does not seems to indicate this info. There is no "official" information, but a blu-ray.com forum member has a regularly-updated list of video & audio bitrates & codecs for most BD titles that have been released. I've posted the link before, but in case people here missed it: http://forum.blu-ray.com/showthread.php?t=3338
Guest jonlee Posted June 7, 2007 Posted June 7, 2007 Doogie, to use coaxial, I should set the coaxial digital out to bitstream, correct? Read from the manual that when playing HDDVD, the XA2 will decode the DD to PCM, then encode it DTS 5.1 and output from the coaxial. However, when I set it to bitstream, when I put in a HDDVD, no sound came out during the initial HDDVD advertisement part. Changed to PCM then can hear sound. Is it due to a wrong audio track selected from the HDDVD? Which button on the remote to press to show the audio info (borrowed from desreay's review): Have not started the movie yet. Coax does not support discrete MPCM. Only stereo PCM or Dolby or DTS encoded multichaneel.
Doggie Howser Posted June 7, 2007 Posted June 7, 2007 Doogie, to use coaxial, I should set the coaxial digital out to bitstream, correct? Read from the manual that when playing HDDVD, the XA2 will decode the DD to PCM, then encode it DTS 5.1 and output from the coaxial. I have not used the recoding of audio codecs on coax/optical before. But I remember the XA2 being crippled (vs the XA1) in that it can't handle recoding of TrueHD and DD+ to 1.5Mbps when it first launched. Not sure if that has changed. Is there an Auto mode. See if it works.
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