[BoW] r18 - trunk/video_coding/h264_based_codecs.tex

[kostya]

Author: kostya
Date: Sun Nov 23 11:04:45 2008
New Revision: 18

Log:
Add a section for documenting RV3/4

Added:
   trunk/video_coding/h264_based_codecs.tex

Added: trunk/video_coding/h264_based_codecs.tex
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+\section{Codecs based on H.264 drafts}
+
+ Since standardisation of video coding formats takes years to complete, some
+ companies produce proprietary codecs based on standard drafts.
+ There are several codecs based on H.264 drafts reviewed below.
+ Those codecs are optimised for decoder performance so they have only basic
+ subset of features (no CABAC or interlaced mode).
+
+ \begin{enumerate}
+  \item
+   Sorenson SVQ3
+
+   It is a Quicktime codec widely used before MPEG-4 became widespread.
+
+  \item
+   RealVideo 3
+
+   This codec bears resemblance to both Sorenson SVQ3 and H.264 drafts.
+
+  \item
+   RealVideo 4
+
+   The second incarnation of Real H.264 draft based codecs has more differences
+   from H.264 drafts.
+
+ \end{enumerate}
+
+ \subsection{Sorenson SVQ3}
+
+ \subsection{RealVideo 3}
+
+ \subsection{RealVideo 4}
+
+   Main differences from RV3:
+   \begin{itemize}
+    \item
+     P-frame blocks can have 16x8, 8x16 or 8x8 motion partitions
+    \item
+     macroblock information (macroblock type, CBP, etc) is coded with code set
+     chosen from neighbouring macroblocks
+    \item
+     loop filter is more sophisticated
+   \end{itemize}
+
+ \begin{table}
+  \caption{H.264 draft based codecs feature comparison}
+  \label{h264draftcomparison}
+  \begin{tabular}{|l|c|l|c|}
+   \hline
+   {\bf Codec} &
+   {\bf MC} &
+   {\bf Coding type} &
+   {\bf DC and AC quantisation} \\ \hline
+   SVQ3 & $1/3$ pel & UVLC & same quantiser\\ \hline
+   RV3  & $1/3$ pel & UVLC & separate quantisers\\ \hline
+   RV4  & $1/4$ pel & context-dependent VLC & separate quantisers\\ \hline
+  \end{tabular}
+ \end{table}