$Id: pyvnc2swf.html,v 1.2 2008/11/16 02:39:40 euske Exp $
Pyvnc2swf is a cross-platform screen recording tool. It captures screen motion through VNC protocol and generates a Shockwave Flash (SWF) movie. Pyvnc2swf suite comes with three Python programs:
edit.py- Movie editor (This is NOT a general SWF file editor. It only supports movies generated by vnc2swf.)
play.py- Simple movie viewer
For questions, please read the FAQ and list archives before sending me emails.
Terms and Conditions: Pyvnc2swf comes with ABSOLUTELY NO WARRANTY. This software is distributed under the GNU General Public License.
In all platforms, the following packages are required:
In most Linux distros, these packages are readily available. In Mac OS X, you would need an additional OS X build of Pygame package.
Also, you need at least one VNC server:
captures a VNC sessions and records it in either SWF or VNCLog format.
This is a VNC client and communicates directly with a VNC server.
A user need to start a VNC server in advance.
vnc2swf.py runs in two different modes:
GUI (Graphical User Interface) mode and CLI (Command Line Interface) mode.
In the GUI mode, start recording by clicking the "Start" button.
Then choose the "Save as..." command from the "File" menu to save
the recorded movie to a file.
In the CLI mode, a user needs to specify the output filename from command line.
Recording is started immediately. In both modes, a user is
prompted for a VNC password if the server requires authentication
(and unless the user doesn't specify the password file).
In the CLI mode, hit Control-C to stop recording.
After finishing recording, it generates two files with the specified name:
to provide seek bar function.
A user can choose three different methods to encode movie image:
mpeg" (PyMedia required),
swf5 encoding (default) provides a reasonable movie size.
The second encoding method,
swf7 provides a smaller SWF movie.
This is, however, not recommended to use within
two reasons: This type of encoding is only supported by Flash Player
version 7 or newer. Also, generating a movie with on-the-fly
swf7 encoding is slower so you might experience frame dropping.
Actually, you can convert a
swf5-encoded movie into
one after recording by using
edit.py, so anyway you don't need to
use this method when recording. The third encoding method is
This method generates a
.vnc (VNCLog) file, which is compatible with
vncrec output file.
You can convert it to a SWF movie with
.vnc file is not a SWF movie by itself, but its encoding is the fastest.
Unlike the C version,
vnc2swf.py doesn't handle any
user interaction. If you want to control the server's desktop,
you need to launch vncviewer or its equivalent separately.
$ vnc2swf.py [-o filename] [options] [host[:display] [port]]
$ vnc2swf.py -n -o filename [options] [host[:display] [port]]
(Record a virtual screen) $ vncserver -geometry 640x480 $ vnc2swf.py -o out.swf localhost:1 (Record an existing screen) $ x11vnc -localhost -viewonly -wait 10 -defer 10 -bg $ vnc2swf.py -o out.swf localhost:0 (Record a remote screen) $ vnc2swf.py -n -o out.flv vnc.example.com:1
If you're using x11vnc, see also recordwin. This is a convenient script to record a particular window.
mpegif you have PyMedia).
swf7files have a limitation and lcan have up to 16000 frames, which is roughly 22 minutes.
x11vnc, try adding
-wait 10 -defer 10.
flvmovie, you can dump a live stream output to stdout by speficing '
-' as a filename. But currently I have no idea how to use. (broadcasting your desktop on the web?)
.swf" or "
.vnc". Otherwise, the user need to specify the output movie encoding with
-toption (see below.)
widthxheight+left+top" (e.g. "
400x300+120+0"). Unlike other X11 applications, all rectangular components are required. Negative values are not supported.
swf7" or "
vnc"). When omitted, the encoding type is automatically inferred from the filename (
vncpasswd. A user can directly specify
~/.vnc/passwd, which normally contains the password for the local vnc server.
-S subprocess(Supported on Un*x only, Python 2.4 or above is required)
edit.py program is for editing or reorganizing one or multiple movies
vnc2swf.py. This program also supports converting
a .vnc file into .swf movie, changing the encoding method (swf5->swf7),
attaching MP3 audio file to a movie, extracting
images from a movie and resampling/scaling/clipping a movie image.
edit.py currently supports only command line interface.
The user must give one output filename and one or more input filename(s).
Input movies are concatenated sequentially (in the specified order)
and the desired effects are applied.
$ edit.py -o outfile.swf [options] infile ...
(Convert .vnc file into .swf with compressed video encoding) $ edit.py -o out.swf -c -t swf7 input.vnc (Attach an mp3 file to .swf) $ edit.py -o out.swf -a voice.mp3 in.swf (Concatenate two movies and extract the frames into another movie) $ edit.py -o out.swf -f 100-200,350- movie1.swf movie2.swf (Clip the top left area of the movie and shrink it to half the size) $ edit.py -o small.swf -C 320x240+0+0 -s 0.5 in.swf (Convert .swf into MPEG) $ edit.py -o out.mpg input.swf (Convert .swf into .flv) $ edit.py -o out.flv input.swf
swf7) types of movies, but usually it's most effective when applied to
|SWF movie (default)|
|SWF movie with stream video encoding support|
|MPEG movie (requires PyMedia)|
|BMP image sequence|
|PNG image sequence|
swf7 encoding is supported only with Flash Player version 7 or newer.
-(hyphen) sign. For example:
10,200,300-400specifies the frames whose number is 10 and 200, plus every frame between frame 300 and 400. The beginning (or ending) frame number can be omitted (e.g.
300-). In this case, the first (or last) frame number is used as the other end of the range.
-F option and
-f option is same except that
chop the audio while
-f does. When you're putting audio on the movie, if
-a option at the same time, it chops an mp3 file
according to the selected frames. However, when you want to cast a continuous sound (such as music)
onto a whole movie, this might not be the desired effect. In such a case, use
widthxheight+left+top" (e.g. "
-K 500) is recommended.
edit.pytries to keep the original frame rate in the output movie.
s' is appended to the number (such as '
1.0s'), it indicates the number of seconds instead of frames. This option is useful when there is a time lag between a recorded image and audio.
flvencoding method (default=32). This must be a multiple of 16.
play.py is a simple player for a
This program might be useful for spotting the right frame number in a recorded movie.
However its speed is awkward and audio output is not supported.
It only supports vnc2swf-generated files and cannot play general SWF movies.
The player accepts the following keys:
q" / Escape: Quit.
s": Take a snapshot. The image is saved as "
$ play.py [options] moviefile ...
widthxheight+left+top" (e.g. "
edit.py. Normally putting keyframes in every 500 frames (
-K 500) gives a reasonable result.
For those who are interested in learning or extending the program, I drew a simple figure to explain how data goes between objects within pyvnc2swf.
<yusuke at cs dot nyu dot edu>