[BoW] r7 - in trunk/audio_coding: audio_coding.tex predicitive_coding.tex

attila subversion at mplayerhq.hu
Sun Sep 28 15:04:09 CEST 2008 

Author: attila
Date: Sun Sep 28 15:04:09 2008
New Revision: 7

Log:
Cosmetics:

* Split audio_coding/predictive_coding into a seperate file
* Start every sentence on a new line
* Break overly long lines



Added:
   trunk/audio_coding/predicitive_coding.tex   (contents, props changed)
      - copied, changed from r6, /trunk/audio_coding/audio_coding.tex
Modified:
   trunk/audio_coding/audio_coding.tex

Modified: trunk/audio_coding/audio_coding.tex
==============================================================================
--- trunk/audio_coding/audio_coding.tex	(original)
+++ trunk/audio_coding/audio_coding.tex	Sun Sep 28 15:04:09 2008
@@ -4,95 +4,6 @@
 
 \section{Quality Metrics}
 
-\section{Predictive Coding}
-
-Prediction is wide-employed method for effective data compression. One can think about prediction as a FIR filter $y_n = x_n - f(x_{n-1}, x_{n-2}, \ddots)$ where $x_n$ is $n$-th input sample and $y_n$ is $n$-th output sample and $f(x)$ is a prediction function. Depending on prediction function type there is  linear prediction (i.e. $y_n = x_n - \sum _{i=0} ^N a_i x_{n-i-1}$) and nonlinear prediction. Prediction is called fixed when prediction function does not employ any internal state and adaptive prediction when
-output depends on some internal state (e.g. linear prediction coefficients are adjusted depending on previous outputs).
-
-Linear prediction is commonly used in audio compression techniques --- (A)DPCM codecs, speech coding, lossless coding.
-
-\subsection{Temporal Correlation}
-
-Temporal correlation means correlating samples in time domain, i.e. predicting next waveform sample and coding the difference.
-
-\subsubsection{DPCM}
-Differential PCM is without a doubt one of the oldest audio compression techniques employed due its very low computation cost. Typical compression ratio is 2.
-
-\begin{verbatim}
-while there are samples left to decode
-    diff <-- get difference
-    predictor <-- predictor + diff
-    output predictor as a new sample
-\end{verbatim}
-
-\subsubsection{ADPCM}
-
-Most popular is IMA ADPCM compression scheme, which is used as a basis for many proprietary variations that are usually used in games and  several widespread ADPCM codecs such as Apple IMA ADPCM and Microsoft IMA ADPCM.
-
-\begin{verbatim}
-while there are samples left to decode
-    diff <-- get difference
-    predictor <-- predictor + diff*step
-    output predictor as a new sample
-    adjust step based on diff
-\end{verbatim}
-
-\begin{table}
-\caption{Known (A)DPCM codecs comparison}
-\label{dpcmcmp}
-\begin{tabular}{|l|l|l|r|r|}
-\hline
-{\bf Name} &
-{\bf Employed at} &
-{\bf Difference type} &
-{\bf Source} &
-{\bf Compression rate}
-\\ \hline
-
-Id RoQ DPCM &
-Id RoQ &
-quadratic &
-16-bit &
-2:1
-\\ \hline
-
-IMA ADPCM &
-WAV, AVI, game formats &
- &
-8-bit, 16-bit &
-4:1
-\\ \hline
-
-Interplay DPCM &
-Interplay MVE &
-custom &
-16-bit &
-2:1
-\\ \hline
-
-MS ADPCM &
-AVI, WAV &
- &
-16-bit &
-4:1
-\\ \hline
-
-Sierra DPCM &
-Sierra .SOL, .VMD &
-logarithmic &
-8-bit, 16-bit &
-2:1
-\\ \hline
-
-Xan DPCM &
-AVI &
-logarithmic &
-16-bit &
-2:1
-\\ \hline
-\end{tabular}
-\end{table}
-
-\subsection{Spatial Correlation}
+\input{audio_coding/predicitive_coding.tex}
 
 \section{Error Concealment}

Copied: trunk/audio_coding/predicitive_coding.tex (from r6, /trunk/audio_coding/audio_coding.tex)
==============================================================================
--- /trunk/audio_coding/audio_coding.tex	(original)
+++ trunk/audio_coding/predicitive_coding.tex	Sun Sep 28 15:04:09 2008
@@ -1,22 +1,28 @@
-\part{Audio Coding}
-
-\section{Psychouacoustics}
-
-\section{Quality Metrics}
-
 \section{Predictive Coding}
 
-Prediction is wide-employed method for effective data compression. One can think about prediction as a FIR filter $y_n = x_n - f(x_{n-1}, x_{n-2}, \ddots)$ where $x_n$ is $n$-th input sample and $y_n$ is $n$-th output sample and $f(x)$ is a prediction function. Depending on prediction function type there is  linear prediction (i.e. $y_n = x_n - \sum _{i=0} ^N a_i x_{n-i-1}$) and nonlinear prediction. Prediction is called fixed when prediction function does not employ any internal state and adaptive prediction when
-output depends on some internal state (e.g. linear prediction coefficients are adjusted depending on previous outputs).
+Prediction is wide-employed method for effective data compression.
+One can think about prediction as a FIR filter
+$y_n = x_n - f(x_{n-1}, x_{n-2}, \ddots)$ where $x_n$ is $n$-th input sample
+and $y_n$ is $n$-th output sample and $f(x)$ is a prediction function.
+Depending on prediction function type there is  linear prediction (i.e.
+$y_n = x_n - \sum _{i=0} ^N a_i x_{n-i-1}$) and nonlinear prediction.
+Prediction is called fixed when prediction function does not employ any
+internal state and adaptive prediction when output depends on some internal
+state (e.g. linear prediction coefficients are adjusted depending on
+previous outputs).
 
-Linear prediction is commonly used in audio compression techniques --- (A)DPCM codecs, speech coding, lossless coding.
+Linear prediction is commonly used in audio compression techniques
+--- (A)DPCM codecs, speech coding, lossless coding.
 
 \subsection{Temporal Correlation}
 
-Temporal correlation means correlating samples in time domain, i.e. predicting next waveform sample and coding the difference.
+Temporal correlation means correlating samples in time domain, i.e. predicting
+next waveform sample and coding the difference.
 
 \subsubsection{DPCM}
-Differential PCM is without a doubt one of the oldest audio compression techniques employed due its very low computation cost. Typical compression ratio is 2.
+Differential PCM is without a doubt one of the oldest audio compression
+techniques employed due its very low computation cost.
+Typical compression ratio is 2.
 
 \begin{verbatim}
 while there are samples left to decode
@@ -27,7 +33,9 @@ while there are samples left to decode
 
 \subsubsection{ADPCM}
 
-Most popular is IMA ADPCM compression scheme, which is used as a basis for many proprietary variations that are usually used in games and  several widespread ADPCM codecs such as Apple IMA ADPCM and Microsoft IMA ADPCM.
+Most popular is IMA ADPCM compression scheme, which is used as a basis for
+many proprietary variations that are usually used in games and  several
+widespread ADPCM codecs such as Apple IMA ADPCM and Microsoft IMA ADPCM.
 
 \begin{verbatim}
 while there are samples left to decode
@@ -95,4 +103,3 @@ logarithmic &
 
 \subsection{Spatial Correlation}
 
-\section{Error Concealment}

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