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-rw-r--r--interfaces.tex10
-rw-r--r--introduction.tex19
2 files changed, 16 insertions, 13 deletions
diff --git a/interfaces.tex b/interfaces.tex
index ef8fb71..703e7a7 100644
--- a/interfaces.tex
+++ b/interfaces.tex
@@ -7,8 +7,8 @@ generate all files separately, one after the other.
Here is an example to generate a two-minute ETI file for a multiplex containing two programmes:
\begin{itemize}
- \item one DAB programme at 128kbps, encoded with toolame-dab
- \item one \dabplus{} programme at 88kbps, encoded with fdk-aac-dabplus
+ \item one DAB programme at 128kbps, encoded with Toolame-DAB
+ \item one \dabplus{} programme at 88kbps, encoded with FDK-AAC-DABplus
\end{itemize}
We assume that the audio data for the two programmes is located in uncompressed
@@ -118,12 +118,12 @@ machine.
\subsubsection{Between Encoder and Multiplexer}
-Between fdk-aac-dabplus and ODR-DabMux, the ZeroMQ connection transmits AAC superframes, with
+Between FDK-AAC-DABplus and ODR-DabMux, the ZeroMQ connection transmits AAC superframes, with
additional metadata that contains the audio level indication for monitoring purposes. The
multiplexer cannot easily derive the audio level from the AAC bitstream without decoding it, so it
makes more sense to calculate this in the encoder.
-The toolame-dab encoder also can send MPEG frames over ZeroMQ, but is not yet able to calculate and
+The Toolame-DAB encoder also can send MPEG frames over ZeroMQ, but is not yet able to calculate and
transmit audio level metadata yet.
On the multiplexer, the subchannel must be configured for ZeroMQ as follows:
@@ -185,7 +185,7 @@ acceptable, e.g. more than once per hour.
Both situations are suboptimal, because they lead to audio glitches, and also degrade the ability to
compensate for network latency changes. It is preferable to use the drift compensation feature
-available in fdk-aac-dabplus, which insures that the encoder outputs the AAC bitstream at the
+available in FDK-AAC-DABplus, which insures that the encoder outputs the AAC bitstream at the
nominal rate, aligned to the NTP-synchronised system time, and not to the sound card clock. The
sound card clock error is compensated for inside the encoder.
diff --git a/introduction.tex b/introduction.tex
index e7eb35a..6e7c441 100644
--- a/introduction.tex
+++ b/introduction.tex
@@ -31,6 +31,8 @@ composing a \mmbtools transmission chain, and how to set one up.
\section{Presentation of the Tools}
\subsection{Origins}
+Before we begin with technical details, first a word about the history of
+the mmbTools.
In 2002, Communications Research Centre Canada\footnoteurl{http://crc.ca}
started developing a DAB multiplexer. This effort evolved through the years, and
was published in September 2009 as \mbox{CRC-DabMux} under the GPL
@@ -55,7 +57,7 @@ In 2012, these tools received experimental support for single-frequency
networks, a functionality that has been developed by Matthias P. Brändli during
his Master's thesis\footnote{The corresponding report is available at
\url{http://mpb.li/report.pdf}}.
-Because SFNs only make sense in TM 1, CRC subsequently released a patch to
+Because SFNs are mainly used in TM 1, CRC subsequently released a patch to
\mbox{CRC-DABMOD} that enabled all four transmission modes.
At that point, involvement from CRC started to decline. The SFN patch was
@@ -72,11 +74,12 @@ become very difficult, if not impossible to acquire licences for the
available, which was part of Google's Android sources. This encoder has been
extended with the necessary \dabplus{}-specific requirements (960-transform,
error correction, framing, etc.), and now exists under the name
-\mbox{fdk-aac-dabplus}.
+\mbox{FDK-AAC-DABplus}.
\subsection{Included Tools}
-The \mmbtools contain the tools \mbox{ODR-DabMux}, \mbox{ODR-DabMod},
-\mbox{toolame-dab}, \mbox{fdk-aac-dabplus}, and other scripts, bits and pieces
+The \mmbtools are composed of several software projects:
+\mbox{ODR-DabMux}, \mbox{ODR-DabMod},
+\mbox{Toolame-DAB}, \mbox{FDK-AAC-DABplus}, and other scripts, bits and pieces
that are useful for the setup of a transmission chain.
\subsubsection{ODR-DabMux}
@@ -107,17 +110,17 @@ output. Other SDR platforms can be used if they are able to accept the I/Q data.
The output of the modulator can also be used in GNURadio if format conversion or
graphical analysis (spectrum) is to be done.
-\subsubsection{toolame-dab}
+\subsubsection{Toolame-DAB}
TooLAME is a MPEG-1 Layer II audio encoder that is used to encode audio for the
DAB standard. The original project has been unmaintained since 2003, but the
twolame fork that pursues the development removed the DAB framing. Because of
this, twolame is not suitable for DAB.
-The toolame-dab fork includes the ZeroMQ output and PAD insertion support, but
+The Toolame-DAB fork includes the ZeroMQ output and PAD insertion support, but
the audio coder is the same as the one in tooLAME.
-\subsubsection{fdk-aac-dabplus}
-The fdk-aac-dabplus encoder can be used to encode for \dabplus. The encoder
+\subsubsection{FDK-AAC-DABplus}
+The FDK-AAC-DABplus encoder can be used to encode for \dabplus. The encoder
itself comes from the Android sources, and was written by Fraunhofer.
The necessary framing and error-correction that \dabplus mandates, the PAD