INTERACT FORUM

More => Old Versions => Media Center 12 (Development Ended) => Topic started by: boliver on November 14, 2007, 06:37:18 pm

Title: HDCD Support
Post by: boliver on November 14, 2007, 06:37:18 pm
Does Mediacenter decode HDCD's correctly?  Would that require outputing in higher than 16 bit audio?

Does any player on the PC do this?

(i.e. you rip the CD in a bit perfect format like WAV or APE so that every bit is there for decoding)
Title: Re: HDCD Support
Post by: Matt on November 14, 2007, 09:04:16 pm
Media Center can pass a bit-perfect stream to the soundcard.  It also uses 32-bits for all audio handling internally.

However, I can't hear past about 13 or 14-bits in a silent room with fancy headphones playing loudly.  So my opinion is that the guys behind the CD got it right with 16-bits.  Now if mastering engineers would stop squishing those 16 bits so much...
Title: Re: HDCD Support
Post by: glynor on November 15, 2007, 01:45:51 am
If you're curious there is an interesting discussion over at Hydrogenaudio about HDCDs and decoding them from a while back: http://www.hydrogenaudio.org/forums/index.php?showtopic=30999

Looks like they agreed with Matt for the most part.  Possible to implement, but pointless because the whole HDCD scheme was more about making money from licensinng fees than actually improving audio quality.
Title: Re: HDCD Support
Post by: mojave on November 15, 2007, 02:01:27 pm
Does any player on the PC do this?

Windows Media Player 9, 10, or 11 will play HDCD's on XP and Windows Media Player 11 on Vista. However, I believe you need a 24 bit soundcard for playback.

I used to play them with WMP 9, but when I purchased Media Center 10 I abandoned WMP 9. At that time you couldn't select codecs with MC. Today you could probably play them back with MC and use a WMP codec. When I used WMP 9, there was also and indicator that showed you were playing an HDCD. I have not seen the indicator with version 10 or 11.

When I played back HDCD's with MC at 24 bits and upsampled to 176,400 Hz, I couldn't tell any difference between the HDCD decoding of WMP 9 and the standard decoding of MC.
Title: Re: HDCD Support
Post by: Alex B on November 15, 2007, 02:45:42 pm
WMP can decode HDCD coded PCM signal only when it comes directly from an Audio CD. It doesn't detect the code when a file is played. As Matt said, MC can send bit perfect data through SPDIF, so if the sound card and its drivers support bit perfect playback it is possible to play ripped HDCD files and use an external HDCD decoder. Some HT-receivers have HDCD decoding.

However, as said, a correctly mastered 16-bit signal is good enough for all practical listening purposes. Unfortunately the on-going "loudness war" in the music industry constantly produces CDs that use only something like 2 bits of the possible 16-bit dynamic range.

I have tried the system described in glynor's HA link and created some 24-bit lossless files from my HDCD discs. These files can be played in the full dynamic range (20-bit) with MC. The file creation process is quite awkward and really not worth the effort.
Title: Re: HDCD Support
Post by: gappie on November 15, 2007, 05:28:18 pm
for fun i just created a small 24 bit 192 kHz file, a wav. and mc played it back fine, needed some time after that to get back to normal though, or maybe it was my soundcard. but first of all, the soundcard should be able playing that back.

i think the 16 vs 24 bit discussion has long beard.
a while back i had the change to hear a cello recording in a studio made at 24 bit 88 kHz vs the same recording at 16/44. there is a difference, as if the cello was played at that moment in that room.
but for use at home i dont care tomuch, and for most music and the way it is produced it is totaly unintresting.
Title: Re: HDCD Support
Post by: Alex B on November 15, 2007, 06:01:17 pm
... a while back i had the change to hear a cello recording in a studio made at 24 bit 88 kHz vs the same recording at 16/44. there is a difference, as if the cello was played at that moment in that room.

It is possible that the difference was audible, but it could have been caused by many factors, not just by the 16/44.1 format limitations. Some possible factors: the quality of the used resampling method, the used DA converter on the playback equipment (some DA converters work better with certain sample rates), slight difference in the playback volume level or EQ (if the playback chain wasn't exactly the same for both formats) and if the listening situation wasn't a controlled ABX blind test a placebo factor is one possibility.
Title: Re: HDCD Support
Post by: gappie on November 16, 2007, 03:18:05 am
It is possible that the difference was audible, but it could have been caused by many factors, not just by the 16/44.1 format limitations. Some possible factors: the quality of the used resampling method, the used DA converter on the playback equipment (some DA converters work better with certain sample rates), slight difference in the playback volume level or EQ (if the playback chain wasn't exactly the same for both formats) and if the listening situation wasn't a controlled ABX blind test a placebo factor is one possibilty.
i agree totally. but never underestimate the importance of placebo. and a controlled double blind test with only a few persons would still have no scientific value.
some other factors. we receive sound not only through our ears. what do tables scientists come up with tell us about the real world.
perfect discussion material for a loud cafe with a good beer.  :)
Title: Re: HDCD Support
Post by: JimH on November 16, 2007, 07:38:17 am
perfect discussion material for a loud cafe with a good beer.  :)
;D
I'm buying.
Title: Re: HDCD Support
Post by: glynor on November 16, 2007, 12:09:48 pm
we receive sound not only through our ears.

Definitely the quote of the day.

Absolutely, gappie.  Absolutely.