INTERACT FORUM

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: What MP3 decoder is build in MC11  (Read 2285 times)

PaVliG

  • Member
  • *
  • Posts: 4
What MP3 decoder is build in MC11
« on: January 06, 2007, 04:39:41 am »

Hi!

I found that you are using an in_mp3 decoder in Media Center 11.
Is it's only a coincidence of decoders filenames, or it a real Winamp in_mp3 decoder (that's not good for me)

How your decoder works at 24-bit?

When output mode is chosen to 24-bit, is decoder really works at 24-bit(floating point)? or it's only convert 16-bit decoded data to 24(32)bit?
Logged

Alex B

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 10121
  • The Cosmic Bird
Re: What MP3 decoder is build in MC11
« Reply #1 on: January 06, 2007, 05:56:28 am »

MC uses JRiver MP3 decoder, which is of very high quality (http://yabb.jriver.com/interact/index.php?topic=37993.msg258591#msg258591). It has nothing to do with Winamp.

The MP3 decoder outputs 16-bit integral. MC can output all decoded formats bit perfectly, but the internal DSP works in 32-bit float. So if any DSP is used (including the Internal Volume and Replay Gain adjustments) the processing is done in 32-bit float. The selected output bit depth is applied after the processing.

I have done some testing with different decoders and I actually think that it may be better to decode lossy formats like MP3 to 16-bit integral. It looks like the peaks that decode over 0 dBfs with floating point decoders contain only encoding artifacts and these artifacts would actually be attenuated if not fully preserved. In any case this is a purely theoretical question because these peaks seem to always be too short for human hearing (below 1 ms).

CD-audio is 16-bit so it does not need more than that. In general, lossy formats do not preserve useful audio information that would need a greater bit depth (16-bit => 96 dB S/N ratio) even if encoded from a higher bit depth source. Everything that is assumed to be below the hearing threshold is already stripped away and the effective S/N is always much lower than 96 dB.
Logged
The Cosmic Bird - a triple merger of galaxies: http://eso.org/public/news/eso0755

PaVliG

  • Member
  • *
  • Posts: 4
Re: What MP3 decoder is build in MC11
« Reply #2 on: January 06, 2007, 07:41:03 am »

MC uses JRiver MP3 decoder, which is of very high quality (http://yabb.jriver.com/interact/index.php?topic=37993.msg258591#msg258591). It has nothing to do with Winamp.

It's very good to using own decoder.

Can you tell me, is there any advantages when I select 24 or 32 bit output?
I have M-Audio Revolution 5.1 soundcard.
Logged

Alex B

  • MC Beta Team
  • Citizen of the Universe
  • *****
  • Posts: 10121
  • The Cosmic Bird
Re: What MP3 decoder is build in MC11
« Reply #3 on: January 07, 2007, 04:34:19 am »

It's very good to using own decoder.

Can you tell me, is there any advantages when I select 24 or 32 bit output?
I have M-Audio Revolution 5.1 soundcard.

I don't think it can make any audible difference. Normally the higher bit depths are useful only in a production environment when the master files are edited multiple times.
Logged
The Cosmic Bird - a triple merger of galaxies: http://eso.org/public/news/eso0755
Pages: [1]   Go Up