[vorbis-dev] Please help me!!

[Hannes]

Hi,

relax, audio isn't so hard to understand at all. At least not the WAV-File thingy.
Here's a good overview on that: 
    http://www.borg.com/~jglatt/tech/wave.htm

WAV-Files were designed to carry sample-based codecs like PCM(which isn't codec just a sample representation), A/u-law (which compresses 12-bit audio to 8 bit via a logarithmic scale) or ADPCM (which uses linear prediction to reduce data rate). All these formats deliver data on a sample basis (one PCM sample in-one XY-sample out - no such thing as audio blocks). Vorbis for example, like other powerful codecs with a high compression rate need to gather data in block, process them, and put them in a file. Which couldn't be an original wav-file, because it doesn't support blocks.

The "frame"-concept within wav-files has been introduced for multichannel storage and comprises (quote)
 "..The sample points that are meant to be "played" (ie, sent to a DAC) simultaneously (. They ) are collectively called a sample frame.." so for stereo you alternatingly store the samples of left and right channel that belong to together, for 5.1 audio you have to store groups of 6 samples each sample clock and so on..

Hope this helped - if you have other questions, feel free to ask.

Maybe not all questions should go over this list, as it was rather established for vorbis-internal discussions..

Bye,
  Hannes

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  ----- Original Message ----- 
  From: Nhan Than 
  To: vorbis-dev at xiph.org 
  Sent: Sunday, March 09, 2003 9:09 AM
  Subject: [vorbis-dev] Please help me!!

<p>  Dear Ogg Vorbis,
  I'm a senior in Information Technology, and my thesis is on Audio Watermarking. As a new starter in audio, I really need your help, and suggestions. I think in order to persue something on Audio I have to know much details about audio formats. So could you please show me where I can find the documents about the information I need ? Finally,could you please answer a confused question in my mind :
  What are the differences between frames in file wav?
  Thank you so much for your time and consideration.
  I'm looking forward to hearing from you soon.
  Sincerely,
  Nhan Than 

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