ffmpeg update to june 23 version which fixes mp4 crash on still frames with 3...

source/patched-ffmpeg-mt/doc/fftools-common-opts.texi

Index: source/patched-ffmpeg-mt/doc/fftools-common-opts.texi
===================================================================
--- source/patched-ffmpeg-mt/doc/fftools-common-opts.texi	(revision 50820)
+++ source/patched-ffmpeg-mt/doc/fftools-common-opts.texi	(working copy)
@@ -6,6 +6,11 @@
 appended after another postfix or used alone. This allows using for
 example 'KB', 'MiB', 'G' and 'B' as postfix.
 
+Options which do not take arguments are boolean options, and set the
+corresponding value to true. They can be set to false by prefixing
+with "no" the option name, for example using "-nofoo" in the
+commandline will set to false the boolean option with name "foo".
+
 @section Generic options
 
 These options are shared amongst the ff* tools.
@@ -77,4 +82,8 @@
 @item debug
 @end table
 
+By default the program logs to stderr, if coloring is supported by the
+terminal, colors are used to mark errors and warnings. Log coloring
+can be disabled setting the environment variable @env{NO_COLOR}.
+
 @end table