Explanation on the workings and methods used by the
Pyramid Vector Quantization Search function
could be found in the following Work-In-Progress mail threads:
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-June/212146.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-June/212816.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-July/213030.html
http://ffmpeg.org/pipermail/ffmpeg-devel/2017-July/213436.htmlSigned-off-by: Ivan Kalvachev <ikalvachev@gmail.com>