This is a thumbnail extractor using the ffmpeg libraries that will eventually
support extracting thumbnails from both image and video files. Compiling
the ffmpeg libraries requires at least GNU make version 3.81.

A local ffmpeg tree is used, because
(1) there are no recent official releases of the ffmpeg libs,
(2) mainline ffmpeg is not reentrant,
(3) security issues can be handled locally.

Current base version fetch:
svn export -r 13836 --ignore-externals svn://svn.mplayerhq.hu/ffmpeg/trunk ffmpeg
svn export -r 27100 svn://svn.mplayerhq.hu/mplayer/trunk/libswscale ffmpeg/libswscale

Plan: test & enable ffmpeg decoders one by one
tests:
- multithreading test
- zzuf test
- random input test
(- valgrind)

At least, the following should be eventually enabled:
if ! ./configure			\
	--prefix=/tmp/FF		\
	--disable-mmx			\
	--disable-altivec		\
	--enable-shared			\
	--enable-swscale		\
	--enable-gpl			\
	--disable-vhook			\
	--disable-postproc		\
	--disable-network		\
	--disable-ffmpeg		\
	--disable-ffserver		\
	--disable-ffplay		\
	--disable-devices		\
	--disable-protocols		\
	--disable-bsfs			\
	--disable-parsers		\
	--disable-muxers		\
	--disable-demuxers		\
	--disable-encoders		\
	--disable-decoders		\
	--enable-parser=h263		\
	--enable-parser=h264		\
	--enable-parser=mjpeg		\
	--enable-parser=mpeg4video	\
	--enable-parser=mpegvideo	\
	--enable-encoder=png		\
	--enable-encoder=mjpeg		\
	--enable-decoder=bmp		\
	--enable-decoder=pcx		\
	--enable-decoder=png		\
	--enable-decoder=mjpeg		\
	--enable-decoder=mjpegb		\
	--enable-decoder=targa		\
	--enable-decoder=tiff		\
	--enable-decoder=flashsv	\
	--enable-decoder=h263		\
	--enable-decoder=flv		\
	--enable-decoder=h264		\
	--enable-decoder=mpeg1video	\
	--enable-decoder=mpeg2video	\
	--enable-decoder=mpegvideo	\
	--enable-decoder=mpeg4		\
	--enable-decoder=vp6		\
	--enable-decoder=vp6a		\
	--enable-decoder=vp6f		\
	--enable-demuxer=asf		\
	--enable-demuxer=avi		\
	--enable-demuxer=flv		\
	--enable-demuxer=mjpeg		\
	--enable-demuxer=mpegps		\
	--enable-demuxer=mpegts		\
	--enable-demuxer=mpegvideo	\
	--enable-demuxer=mov		\
	--enable-demuxer=ogg		\
	--enable-demuxer=rm

