+.. _kaeru:
+
+Transcoding with Kaeru
+----------------------
+
+There is a third option that combines elements from the two previous
+approaches: Since version 1.6.1, Nageru includes **Kaeru**, named after the
+Japanese verb *kaeru* (換える), meaning roughly to replace or exchange.
+Kaeru is a command-line tool that is designed to transcode Nageru's streams.
+In that aspect, it is similar to using VLC as described in the section on
+:ref:`transcoded streaming <transcoded-streaming>`. However, since it reuses
+Nageru's decoding and encoding code, it can do almost everything you can do
+with :ref:`direct encoding <direct-encoding>`, including x264 speed control
+and Metacube output (see the section on :ref:`Cubemap integration <cubemap>` below).
+
+Using Kaeru is similar to launching Nageru, e.g. to rescale a stream to 848x480::
+
+ ./kaeru -w 848 -h 480 --http-mux mp4 --http-audio-codec libfdk_aac --http-audio-bitrate 128 \
+ http://yourserver.example.org:9095/stream.nut
+
+Unlike the VLC option, Kaeru will automatically reconnect if the source goes
+away, so you do not need a while loop. Note that if you want to keep the audio
+unchanged (usually audio is more important than video, so it's not uncommon to
+want to transcode video but not audio), you can do so with the flag
+*--no-transcode-audio* flag.
+
+There are some things you should keep in mind about Kaeru:
+
+ - Kaeru is currently quite experimental, and much less tested than Nageru itself.
+ - Kaeru does not use the GPU; it uses FFmpeg's code for scaling and colorspace
+ conversion. This yields somewhat lower scaling quality and uses more CPU power,
+ but means you can run it on a headless server.
+ - There is no support for encoding using Quick Sync Video, since this depends on the GPU.
+ - 10-bit output is currently not supported.
+
+
+.. _cubemap:
+