~$ gnash  -v -M ffmpeg 'http://www.youtube.com/v/4xeivKv5sMs?version=2'
18357:1] 202 SECURITY: Checking security of URL 'http://www.youtube.com/v/4xeivKv5sMs?version=2'
18357:1] 202 SECURITY: Load from host www.youtube.com granted (default)
18357:1] 1324 SECURITY: Extensions disabled
18357:2] 1334 UNIMPLEMENTED: FileAttributes tag in the SWF requests that network access is not granted to this movie (or application?) when loaded from the filesystem. Anyway Gnash won't care; use white/black listing in your .gnashrc instead
18357:3] 1342 SECURITY: Checking security of URL 'https://s.ytimg.com/yts/swfbin/player-vfl44xCgu/cps.swf'
18357:3] 1348 SECURITY: Load from host s.ytimg.com granted (default)
18357:1] 2871 UNIMPLEMENTED: System.security.allowDomain
18357:1] 2985 UNIMPLEMENTED: TextField.setNewTextFormat(), we'll delegate to setTextFormat
18357:1] 3186 SECURITY: SharedObject '/home/rwilbur/.gnash/SharedObjects/www.youtube.com//soundData.sol' written to filesystem.
18357:1] 3318 UNIMPLEMENTED: MovieClip.filters()
18357:1] 3828 ERROR: No Video info in video definition
18357:1] 3905 UNIMPLEMENTED: System.security.loadPolicyFile
18357:3] 3905 SECURITY: Checking security of URL 'https://i1.ytimg.com/vi/4xeivKv5sMs/hqdefault.jpg'
18357:3] 3905 SECURITY: Load from host i1.ytimg.com granted (default)
18357:1] 4020 UNIMPLEMENTED: accessibility_updateProperties
18357:3] 5422 UNIMPLEMENTED: Requested to keep from completely loading a movie, but the movie in question is an image, for which we don't yet have the concept of a 'loading thread'
18357:1] 25421 SECURITY: Checking security of URL 'https://www.youtube.com/get_video_info?video_id=4xeivKv5sMs&sts=16010&el=embedded&ps=default&eurl=&hl=en_US'
18357:1] 25421 SECURITY: Load from host www.youtube.com granted (default)
18357:1] 26874 SECURITY: Connecting to movie: http://r2---sn-uigxxnpmut-qxoe.googlevideo.com/videoplayback?ms=au&itag=18&source=youtube&mv=m&sver=3&upn=h82Y1Bl9UX4&ip=69.163.83.122&sparams=id%2Cip%2Cipbits%2Citag%2Cratebypass%2Csource%2Cupn%2Cexpire&expire=1383830595&fexp=906094%2C942406%2C924616%2C907231&ratebypass=yes&id=e317a2bcabf9b0cb&key=yt5&ipbits=0&mt=1383807510&signature=1E49412DE2EFF49321E1B9FF7395B3A9D2F9E3DB.74D169FE3CA4C716D96F56ED2303EAC88D9AA4EF&ptk=e-Muzyka&cm2=0
18357:1] 26874 SECURITY: Checking security of URL 'http://r2---sn-uigxxnpmut-qxoe.googlevideo.com/videoplayback?ms=au&itag=18&source=youtube&mv=m&sver=3&upn=h82Y1Bl9UX4&ip=69.163.83.122&sparams=id%2Cip%2Cipbits%2Citag%2Cratebypass%2Csource%2Cupn%2Cexpire&expire=1383830595&fexp=906094%2C942406%2C924616%2C907231&ratebypass=yes&id=e317a2bcabf9b0cb&key=yt5&ipbits=0&mt=1383807510&signature=1E49412DE2EFF49321E1B9FF7395B3A9D2F9E3DB.74D169FE3CA4C716D96F56ED2303EAC88D9AA4EF&ptk=e-Muzyka&cm2=0'
18357:1] 26874 SECURITY: Load from host r2---sn-uigxxnpmut-qxoe.googlevideo.com granted (default)
18357:3] 30822 SECURITY: Checking security of URL 'https://www.youtube.com/ptracking?pltype=contentugc&ptchn=undefined&oid=Fui4NOug_Ci324lNj82y1w&ei=QDp7UuaXE6vPggKSloGoAw&plid=AATqkM2YdS1ZKIHK&ptk=e-Muzyka&video_id=4xeivKv5sMs'
18357:3] 30822 SECURITY: Load from host www.youtube.com granted (default)
18357:1] 30880 UNIMPLEMENTED: Rectangle_intersects
[swscaler @ 0xb4d0d000]No accelerated colorspace conversion found.
18357:1] 31577 ERROR: outputSize:0 after decoding 9 bytes of input audio data. Upgrading ffmpeg/libavcodec might fix this issue.
18357:1] 31932 UNIMPLEMENTED: MovieClip.unloadMovie()
18357:3] 32555 ERROR: Can't read file header
18357:3] 32555 ERROR: Unknown file type
18357:3] 32591 ERROR: Couldn't load library movie 'https://www.youtube.com/ptracking?pltype=contentugc&ptchn=undefined&oid=Fui4NOug_Ci324lNj82y1w&ei=QDp7UuaXE6vPggKSloGoAw&plid=AATqkM2YdS1ZKIHK&ptk=e-Muzyka&video_id=4xeivKv5sMs'
18357:3] 32591 SECURITY: Checking security of URL 'https://s2.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&rt=1.444&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&yttk=1&et=0.472&st=0.472&asv=2&ctp=1'
18357:3] 32592 SECURITY: Load from host s2.youtube.com granted (default)
18357:3] 34286 ERROR: Can't read file header
18357:3] 34286 ERROR: Unknown file type
18357:3] 34321 ERROR: Couldn't load library movie 'https://s2.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&rt=1.444&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&yttk=1&et=0.472&st=0.472&asv=2&ctp=1'
18357:3] 34321 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&rt=1.022&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=0.064&et=0.064&playback=1&fv=LNX%2010%2C1%2C999%2C0'
18357:3] 34321 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 35862 ERROR: Can't read file header
18357:3] 35862 ERROR: Unknown file type
18357:3] 35900 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&rt=1.022&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=0.064&et=0.064&playback=1&fv=LNX%2010%2C1%2C999%2C0'
18357:3] 41646 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=11.052&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=0&et=8.011'
18357:3] 41646 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 43319 ERROR: Can't read file header
18357:3] 43319 ERROR: Unknown file type
18357:3] 43354 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=11.052&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=0&et=8.011'
18357:3] 51703 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=21.109&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=8.011&et=17.607'
18357:3] 51703 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 53507 ERROR: Can't read file header
18357:3] 53507 ERROR: Unknown file type
18357:3] 53533 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=21.109&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=8.011&et=17.607'
18357:3] 61673 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=31.078&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=17.607&et=26.943'
18357:3] 61673 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 63246 ERROR: Can't read file header
18357:3] 63246 ERROR: Unknown file type
18357:3] 63290 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=31.078&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=17.607&et=26.943'
18357:3] 101799 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=71.198&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=26.943&et=66.606'
18357:3] 101799 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 103390 ERROR: Can't read file header
18357:3] 103390 ERROR: Unknown file type
18357:3] 103430 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=71.198&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=26.943&et=66.606'
18357:3] 141644 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=111.05&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=66.606&et=105.926'
18357:3] 141644 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 143247 ERROR: Can't read file header
18357:3] 143247 ERROR: Unknown file type
18357:3] 143283 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=111.05&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=66.606&et=105.926'
18357:3] 181656 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=151.059&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=105.926&et=145.476'
18357:3] 181656 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 183257 ERROR: Can't read file header
18357:3] 183257 ERROR: Unknown file type
18357:3] 183294 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=151.059&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=105.926&et=145.476'
18357:1] 217352 SECURITY: Checking security of URL 'https://www.youtube.com/set_awesome?&video_id=4xeivKv5sMs&l=253&t=vjVQa1PpcFPk0eKdGJfcWlTR4GbKxwvU18ssLhWqfOk=&w=0.713509881422925&ps=default&el=embedded&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw'
18357:1] 217352 SECURITY: Load from host www.youtube.com granted (default)
18357:3] 221819 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=191.218&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=145.476&et=180.808'
18357:3] 221819 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 223447 ERROR: Can't read file header
18357:3] 223447 ERROR: Unknown file type
18357:3] 223487 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=191.218&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=145.476&et=180.808'
18357:3] 261829 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=231.229&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=181.716&et=223.974'
18357:3] 261829 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 263432 ERROR: Can't read file header
18357:3] 263432 ERROR: Unknown file type
18357:3] 263462 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=231.229&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=1&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=181.716&et=223.974'
18357:3] 291023 SECURITY: Checking security of URL 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=260.429&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=2&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=223.974&et=252.757'
18357:3] 291023 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 292465 ERROR: Can't read file header
18357:3] 292465 ERROR: Unknown file type
18357:3] 292509 ERROR: Couldn't load library movie 'https://s.youtube.com/s?ns=yt&docid=4xeivKv5sMs&el=embedded&ps=default&fexp=907231,924616&hl=en_US&hbd=4421825&hbt=48.796999999919&vtmp=1&rt=260.429&plid=AATqkM2YdS1ZKIHK&ei=QDp7UuaXE6vPggKSloGoAw&cpn=dYjNnSegnqFxalJf&fmt=18&vq=auto&volume=86&mos=0&pbs=2&idpj=-7&ldpj=-22&w=640&h=455&len=253&st=223.974&et=252.757'
18357:3] 292509 SECURITY: Checking security of URL 'https://s.youtube.com/stream_204?vsp=1&ps=default&el=embedded&event=streamingerror&ei=QDp7UuaXE6vPggKSloGoAw&plid=AATqkM2YdS1ZKIHK&v=4xeivKv5sMs&erc=1&shost=r2---sn-uigxxnpmut-qxoe.googlevideo.com&fmt=18&end=252.757&len=253&t=vjVQa1PpcFPk0eKdGJfcWlTR4GbKxwvU18ssLhWqfOk=&fv=LNX%2010%2C1%2C999%2C0&bc=-1&ec=104'
18357:3] 292509 SECURITY: Load from host s.youtube.com granted (default)
18357:3] 294201 ERROR: Can't read file header
18357:3] 294201 ERROR: Unknown file type
18357:3] 294242 ERROR: Couldn't load library movie 'https://s.youtube.com/stream_204?vsp=1&ps=default&el=embedded&event=streamingerror&ei=QDp7UuaXE6vPggKSloGoAw&plid=AATqkM2YdS1ZKIHK&v=4xeivKv5sMs&erc=1&shost=r2---sn-uigxxnpmut-qxoe.googlevideo.com&fmt=18&end=252.757&len=253&t=vjVQa1PpcFPk0eKdGJfcWlTR4GbKxwvU18ssLhWqfOk=&fv=LNX%2010%2C1%2C999%2C0&bc=-1&ec=104'
18357:1] 356158 SECURITY: SharedObject '/home/rwilbur/.gnash/SharedObjects/www.youtube.com//soundData.sol' written to filesystem.
18357:1] 356181 SECURITY: SharedObject '/home/rwilbur/.gnash/SharedObjects/www.youtube.com//videostats.sol' written to filesystem.
~$ gnash -vv --version
Gnash 0.8.10 (0.8.10-20120131-none)

Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
Gnash comes with NO WARRANTY, to the extent permitted by law.
You may redistribute copies of Gnash under the terms of the GNU General
Public License.  For more information, see the file named COPYING.

Build options 
   Renderers: agg cairo
   Hardware Acceleration: none
   GUI: GTK
   Media handlers: gst ffmpeg 
   Configured with: CFLAGS=-Wall -g -Werror-implicit-function-declaration -O2 CXXFLAGS=-g -O2 --host=i486-linux-gnu --build=i486-linux-gnu --prefix=/usr --sysconfdir=/etc --mandir=/usr/share/man --infodir=/usr/share/info --with-plugins-install=system --disable-dependency-tracking --disable-testsuite --disable-rpath --enable-cygnal --enable-renderer=agg,cairo --enable-extensions=fileio,lirc,mysql --enable-jemalloc --enable-media=gst,ffmpeg --enable-gui=gtk,qt4
   CXXFLAGS: -g -O2          -W     -Wall     -Wcast-align     -Wcast-qual     -Wpointer-arith     -Wreturn-type     -Wnon-virtual-dtor     -Wunused      -fvisibility-inlines-hidden
~$