xp-replay - Playback an XPilot session.
xp-replay [-help] [-scale factor] [-gamma factor] [-
compress] [-verbose] inputfile
Xp-replay is a program to view an XPilot recording. It takes
record files produced by xpilot(6) and allows the user to
replay them and make snapshots of frames.
-help Prints some help, including commandline
-verbose Prints some information about the record
-compress Save frames in compress format using the
-scale factor Sets the scale reduction factor for saving
operations. Valid scale factors are in the
range [0.01 - 1.0].
-gamma factor Sets the gamma correction factor when saving
scaled frames. Valid gamma correction
factors are in the range [0.1 - 10].
If the filename given is `-' then the standard input is
read. Frames read from the standard input are stored in
memory to allow the user to jump backward and forward
through them, however, with large record files earlier
frames may be discarded to make way for later frames. This
will mean that it may not be possible to jump back to the
start of a large recording. This restriction only affects
files read from pipes.
THE GRAPHICAL USER INTERFACE
When you start the program you will be presented two
windows. The first and largest window is the recording view
window where you will see the recorded game. The second
window is the control window which contains a row of
pushbuttons and which shows some information about the
recorded game. A third window may be popped up giving access
to the controls to save frames.
The buttons in the control window allow you to move through
the recording. They are, from left to right: record,
rewind, reverse play, play, fast-forward, pause, stop and
eject. The symbols on them match the standard symbols seen
on tape and CD players.
Just below the buttons is information about the recording.
The position of the current frame within the recording, the
server the game was played on, the player's nickname and
username, the client that the player connected from and the
number of frames per second the server was running at.
Playback can be in either of two modes - normal or paused.
In normal mode the recording will play back in real time as
close to the original frame rate as possible. In paused
mode, you can single step through frames.
In addition to the buttons certain keys perform shortcuts.
Record This button pops up a window allowing you to
mark frames for recording, and to save the
marked frames in either a standard graphics
format (ppm) or in the XPilot Record format.
Rewind In normal mode this plays the recording
backwards at 10 times normal speed. In paused
mode this button steps backward 10 frames.
Reverse play In normal mode this plays the recording
backwards. In paused mode it single steps
backward one frame.
Play In normal mode this plays the recording
forward at normal speed. In paused mode it
single steps forward 1 frame.
Fast-forward In normal mode this plays the recording
forward at 10 times normal speed. In paused
mode it steps forward 10 frames.
Pause This suspends playback and switches to paused
Stop This suspends playback and switches to normal
Eject This quits the program.
f, space Step forward 1 frame.
b, delete, backspace
Step backward one frame.
z Go to frame zero.
[ Mark this as the first frame to be saved.
] Mark this as the last frame to be saved.
* Save marked frames in PPM format.
& Save marked frames in XPilot Recording
q Quit the program.
Either by using the keys, or the popup record window, you
can mark a section of the playback for recording. To do
that, you move to the first frame you wish to save and mark
it as the first frame. Then move to the last frame and mark
that. Then save the marked frames. When saving in PPM format
the frames will be saved in files called xpNNNNN.ppm. Each
frame wil be placed in a separate file, and the NNNNN will
be replaced by the frame number within the original
recording. When saving in XPilot Recording format the
frames will be saved in one new file called xpN-M.xpr, where
N is the frame number of the first frame and M is the frame
number of the last frame to be saved.
Since having a large number of PPM files can be quite costly
in diskspace, an option exists to automatically shrink them
whilst saving. Use the -scale option to specify a scaling
factor, for example, a scale factor of 0.25 on a 768x768
recording would result in the saved frames being 192x192.
When a frame is shrunk like that, the thin lines draw by
xpilot can appear dimmed. To overcome this, use the -gamma
option with a gamma value greater than 1. That should
brighten up the saved frames. In addition a -compress
option is available to save files in compressed format.
The simplest invocation is
which will play back a recording, and save frames at the
To save frames smaller that the original size use something
xp-replay -scale 0.5 -gamma 2 test-recording.xpr
which will save frames at half size.
You may want to compress the recording files to save disk
space. You can then play them back directly without
uncompressing them first using
zcat test-recording.xpr.Z | xp-replay -
however, this may limit your ability to rewind through the
xp-replay automatically recognizes if a file is in compress
format and gzip format. If this is the case then it
automatically starts compress -d or gzip -d to uncompress
the file before playback.
xp-replay was originally designed and developed by Steven
Singer (S.Singer@ph.surrey.ac.uk). Additional develpoment
was performed by Bert Gijsbers (firstname.lastname@example.org).
The scaling and gamma correction code was taken from the
pbmplus package, which is Copyright (C) 1989, 1991 by Jef
Bugs can be mailed to email@example.com.
xpilot(6), xpilots(6), ppm(5), compress(1), gzip(1)