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Bit-perfect playback questions
XeR0
post Jun 22 2011, 22:28
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I'd say I've gotten into serious music listening the moment I learned that MP3's were lossy and that there IS a difference in SQ based on how the audio was ripped from the CD and how it was encoded. Since then, I've collected my music collection in lossless quality, invested in a pair of high quality headphones, and researched into digital audio in general.

For the most part, I've been able to learn pretty much the basics. However, I've recently stumbled upon a topic that I have yet to understand and find a straightforward answer to: bit-perfect playback. I've learned so far that Windows has an internal mixer that resamples audio played before it goes through the speakers. This internal mixer (generally speaking) decreases or alters the sound quality of an audio file before it reaches the speakers. Plugins such as WASAPI and ASIO bypass this mixer in order for the bits played to reach the headphones unaltered. I know what I'm saying may be incorrect but bear with me since I am fairly new to this.

Further research shows that in Windows Vista and 7, does not require WASAPI or ASIO plugins for bit-perfect playback because the sound settings are automatically sampled above 16bit/44.1KHz (mine are at 24bit/48KHz) and so if the audio is <= that sampling rate, the audio is essentially unaltered. However, other sources state otherwise.

In short, I've yet to find a simple answer to the following questions:
1) Does one NEED WASAPI or ASIO in order to enjoy bit-perfect playback?
2) Is bit-perfect playback even something worth pursuing? (I know it's left up to the listeners ears but let us assume I can pickup the slightest change in quality)
3) If neither is needed, then what sampling rate should I set for "Sound Settings" in Windows 7 to achieve bit-perfect playback?
4) Generally, I'm a bit confused about the whole topic. I've checked out certain sites like thewelltemperedcomputer.com which has shed some light but still hasn't explained everything.

I've read these forums for quite some time and I must thank the entire community because without this site, I wouldn't have learned what I know now about digital audio. For this reason, I've decided to become a member.

Stats:
OS: Windows 7 64-bit
Music Player: Winamp v5.61
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JimH
post Dec 16 2011, 01:46
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QUOTE (googlebot @ Dec 15 2011, 17:06) *
You can get bitperfect output with any plain old media player over DirectSound if you leave your device's sample rate at the same setting as your files (e. g. 44.1 kHz) and set the volume to 100% since Vista.

This thread is hysterical and BS marketing driven.

16 bit INT -> 32 bit FLOAT -> 16 bit INT conversion, et ceteris paribus, is lossless, before you start the "but, but, but ... float pipeline"-whining.

Mr Bot,
I would like to be able to discuss this without fightin' language. My post addressed the user's question. There was no "BS marketing". I admit I can be guilty of "BS".

I'm just one of a very good team, a very serious team, of people who have been in full pursuit of the best audio possible for the last 13 years now.

Let's just talk.

JRiver
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saratoga
post Dec 16 2011, 08:15
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QUOTE (JimH @ Dec 15 2011, 19:46) *
I would like to be able to discuss this without fightin' language. My post addressed the user's question. There was no "BS marketing". I admit I can be guilty of "BS".


I don't know if I'd call it "BS", but if you're getting dramatic differences between DirectSound and ASIO/WASAPI you're probably doing something very, very wrong.
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Roseval
post Dec 16 2011, 11:18
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16 int > 32 float > 16 int is a lossless conversion, Don't think anybody will deny
16 int > 32 float > 16 int > dither is not lossless by design.
It will affect the LSB so there is a small effect.

As far as I know, every media player applies dither on 16 bits material the moment any kind of DSP is applied. Looks like each and everybody thinks it is a necessary step to improve sound quality.

This post has been edited by Roseval: Dec 16 2011, 11:18


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saratoga
post Dec 16 2011, 21:08
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QUOTE (Roseval @ Dec 16 2011, 05:18) *
16 int > 32 float > 16 int > dither is not lossless by design.


Its :

"16 int > 32 float > dither > 16 int "

The dither is applied to the FP data, not the integer.

QUOTE (Roseval @ Dec 16 2011, 05:18) *
Looks like each and everybody thinks it is a necessary step to improve sound quality.


If you're going to convert from high precision to lower precision then you should apply dither. The only time not to is the trivial case where you have 16 > 32 > 16 with no actual processing at the higher precision. I have no idea idea what software is smart enough to handle this. I don't think it really matters unless you're trying to stream a compressed audio format through a digital interface.
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Roseval
post Dec 16 2011, 21:17
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QUOTE (saratoga @ Dec 16 2011, 21:08) *
"16 int > 32 float > dither > 16 int "



Thanks, is more precise

But is does affect the LSB of the 16 bit result anyway


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Posts in this topic
- XeR0   Bit-perfect playback questions   Jun 22 2011, 22:28
- - mixminus1   QUOTE (XeR0 @ Jun 22 2011, 14:28) I'v...   Jun 22 2011, 23:21
- - XeR0   Thanks man. You cleared up the confusion with Wind...   Jun 22 2011, 23:28
- - DVDdoug   I'm not an expert on how to get bit-perfect au...   Jun 23 2011, 00:54
- - XeR0   DVDdoug: Your response pretty much answered most (...   Jun 23 2011, 01:27
|- - greynol   QUOTE (XeR0 @ Jun 22 2011, 17:27) I try n...   Jun 23 2011, 02:11
|- - XeR0   QUOTE (greynol @ Jun 22 2011, 21:11) Can ...   Jun 23 2011, 04:26
|- - dhromed   QUOTE (XeR0 @ Jun 23 2011, 05:26) QUOTE (...   Jun 23 2011, 11:03
|- - Notat   QUOTE (XeR0 @ Jun 22 2011, 21:26) Please,...   Jun 24 2011, 01:41
- - Notat   There are two things that the PC sound system can ...   Jun 23 2011, 01:31
- - greynol   Properly controlled, level matched and time synchr...   Jun 23 2011, 04:47
|- - XeR0   QUOTE (greynol @ Jun 22 2011, 23:47) I ho...   Jun 23 2011, 05:02
- - andy o   If you use HDMI audio there are practical benefits...   Jun 23 2011, 13:39
- - XeR0   QUOTE (dhromed @ Jun 23 2011, 06:03) Have...   Jun 24 2011, 19:13
- - megaoptimus   I've been doing a lot of reading about this la...   Jul 30 2011, 21:49
|- - greynol   QUOTE (megaoptimus @ Jul 30 2011, 13:49) ...   Jul 30 2011, 22:34
- - Alikris   QUOTE So, if you think you can hear a difference a...   Dec 5 2011, 11:29
|- - dhromed   QUOTE (Alikris @ Dec 5 2011, 12:29) Even ...   Dec 5 2011, 16:34
- - Alikris   Yes, especially considering the present HDD shorta...   Dec 5 2011, 20:06
|- - FreaqyFrequency   QUOTE (Alikris @ Dec 5 2011, 14:06) Yes, ...   Dec 5 2011, 21:04
- - Roseval   QUOTE (XeR0 @ Jun 22 2011, 22:28) 1) Does...   Dec 6 2011, 00:31
- - googlebot   You can get bitperfect output with any plain old m...   Dec 16 2011, 00:06
|- - andy o   QUOTE (googlebot @ Dec 15 2011, 15:06) Yo...   Dec 16 2011, 06:52
- - monkey   I believe Jim is implying WASAPI exclusive when ta...   Dec 16 2011, 01:26
- - DVDdoug   QUOTE As far as I know, every media player applies...   Dec 16 2011, 21:44
|- - Arnold B. Krueger   QUOTE (DVDdoug @ Dec 16 2011, 15:44) QUOT...   Dec 4 2012, 16:40
- - Roseval   But if you configure your media player not to appl...   Dec 16 2011, 21:56
- - Joe Bloggs   Is there a way to disable dithering in the windows...   Dec 4 2012, 16:29
- - nu774   QUOTE (Joe Bloggs @ Dec 5 2012, 00:29) Is...   Dec 4 2012, 17:43


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