+\textit{NOTE:} for vp9, the best Pixels is \textit{gbrp}
+
+\subsection{Use case: High Efficiency Video Coding (HEVC)}%
+\label{sub:use_case_hevc}
+
+An example of video profile based on CRF, a quality-controlled
+variable bitrate, instead of fixed quality scale (ABR). HEVC
+(H.265) was developed as a successor to AVC (H.264) to more
+efficiently compress the future large amounts of data from 2/4/8k
+videos. In comparison to AVC, an average saving of around 30
+percent can be assumed for the same quality. Because HEVC is not
+bound to any size format, it is suitable for virtually any image
+size.
+
+The following example is HD and FullHD oriented and produces a
+picture quality similar to the Blu-ray with some limitations. As
+container Matroska (\texttt{.mkv}) is used, but also mp4 and others
+are possible.
+
+\begin{lstlisting}[style=sh]
+matroska libx265
+
+# CRF 16 creates a balanced compromise
+# between quality and file size.
+crf=16
+
+# Preset changes encoding speed and generally
+# degrades the overall result. Medium (default)
+# always fits.
+preset=medium
+
+# Additional parameters that are passed on to the codec.
+# me=star improves the search for very fast
+# movements, but slows down the encoding.
+#x265-params=me=star
+
+# Keyint does FFmpeg automatically, otherwise
+# the setting must match the frame rate.
+#keyint_min=25
+
+# Profile does FFmpeg automatically.
+#profile=high
+
+# Source sRBG and retention of color space.
+# 720/1080=bt709 if no profile set. Useful
+# for formats smaller than 720 if no lossy
+# conversion is desired.
+colorspace=bt709
+color_trc=bt709
+color_primaries=bt709
+
+# Output in 10 bit, prevents 8-bit step formation
+pixel_format=yuv420p
+\end{lstlisting}
+
+\noindent \textit{NOTE:}
+
+A CRF of 16 delivers satisfactory results in most cases. However, if
+the video material is really \emph{grainy}, a CRF~16 can lead to
+unwanted large files. In this case, a trial export of perhaps one
+minute should be performed. The resulting bit rate can be used to
+correct the CRF to 17,\,18,\,19\ldots -- remember, a CRF of $0$ (zero)
+means lossless, the higher the number the stronger the lossy
+compression. The approximate calculation of the final file size can
+be extrapolated from the sample export.
+
+The color space information must be used explicitly so that it can
+be included in the video. \CGG{} or FFmpeg does not write it by
+itself. Without this information the players (e.\,g.\
+\href{https://mpv.io/}{mpv}) stick to the dimensions of the video
+and take the assumed color model from a table. With videos in the
+dimensions from 720 to 1080 this is bt709. For smaller dimensions,
+e.\,g.\ DVD, bt601 is assumed and for 4k and above it is
+bt2020. Normally this is not a problem, but if you want to export a
+FullHD without color loss to a smaller size like 576 for example,
+you have to inform the encoder as well as the decoder of the
+player. This also applies if the videos are to be loaded on video
+platforms, where they are then converted into videos of different
+sizes. It is a security measure to prevent false colors, such as the
+color profiles in digital photos and the copies made from them.
+
+The HEVC tuning has not been considered here, because it is is
+rarely used and requires background knowledge.
+
+Further links:
+\begin{itemize}
+\item \href{http://x265.readthedocs.org/en/default/}{x265
+ Documentation}
+\item \href{http://x265.readthedocs.org/en/latest/cli.html}{x265
+ Command Line Options}
+\item \href{http://x265.readthedocs.org/en/latest/presets.html}{x265
+ Presets/Tuning}
+\end{itemize}
+