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lavplay(1)		       MJPEG tools manual		      lavplay(1)

NAME
     lavplay - Playback and edit MJPEG video

SYNOPSIS
     lavplay [options] lavfile1 [lavfile2 ... lavfileN]

DESCRIPTION
     lavplay  can be used to playback video in MJPEG format (either quicktime or
     AVI) on a zoran video-capture device, such as  the  Miro/Pinnacle	DC10(+),
     the Iomega Buz or Linux Media Labs' LML33, or in software mode (using SDL).

     It also provides mechanisms for non-destructive editting video using an in-
     teractive	front-end  such as glav(1).  See SEARCHING AND EDITING below for
     details.

OPTIONS
     lavplay accepts the following options:

     -p/--playback [S|C|H]
	     The playback mode to be used.  'S'  means	software-playback  using
	     SDL.
	      'H'  means hardware-playback on the monitor (on-screen). 'C' means
	     hardware-playback to the video-out of the zoran  video-capture  de-
	     vice.   Obviously,  'C'  and  'H' only work on computers with zoran
	     video-capture devices.

     -Z/--full-screen
	     Full-screen playback. This works if SDL-  or  onscreen-playback  is
	     chosen.

     --size NxN
	     Size  of  the  video window (default: size of the input video) when
	     using software (SDL) or hardware onscreen playback

     -a/--audio num
	     When play audio, 0 means never, or sum of
	       1: while playing forward,
	       2: while playing reverse,
	       4: even fast playing,
	       8: while pausing
	     (default: 7: forward/reverse/fast).  If 8(pausing)  was  contained,
	     lavplay  will  be	very  noisy, but useful when you want to edit by
	     sound.

     -z/--zoom
	     Zooms the video to fit the screen as good as possible.

     -x      Exchange fields of an interlaced video. Try this if the video looks
	     weird.   It  shouldn't  be  necessary  with  stuff  captured  using
	     lavrec(1) but could be needed for other sources.

     -s/--skip num
	     Skip <num> seconds of video at the beginning.

     -x/--exchange-fields
	     Invert  field order (for videos which are recorded with wrong field
	     order interlacing settings)

     -F/--flicker
	     Disable stills flicker reduction.	This is useful if  you	want  to
	     see stills exactly as they were recorded rather than flicker-free!

     -c/--synchronization [0|1]
	     Enables (1) or disables (0) the use of sync corrections. Basically,
	     you  almost certainly want this.  Disabling is really there for di-
	     agnostic purposes and not much else.

     -H/--H-offset num, -V/--V-offset num
	     Horizontal (-H) and vertical (-V) offset when using  hardware-play-
	     back.   Offset plus width or height should be smaller than or equal
	     to the playback device's maximum allowed size  (DC10+:  640x480  or
	     768x576, LML33/Marvel/Buz: 720x480/576).

     --s-x-offset num, --s-y-offset num
	     Offset  for the video window (from top left screen corner) when us-
	     ing hardware onscreen playback in non-fullscreen mode.

     --display :x.x
	     When using hardware fullsreen video playback  (-pH),  this  setting
	     can be used to specify the video display (default: :0.0) to use for
	     video display.

     -q/--no-quit
	     Makes  lavplay  stay  alive  at the end of the video (lavplay won't
	     quit).  Use 'q<enter>' on the command  line  to  quit  (see  below,
	     SEARCHING AND EDITING).

     -g/--gui-mode
	     Enables  GUI-mode.  This is used by glav and Linux Video Studio. It
	     will output the current position in the video each frame,	so  that
	     the  glav	or LVS can keep track of where we are in the video which
	     is being played back.

     -P/--preserve-pathnames
	     This is used by glav and Linux Video Studio.   When  editlists  are
	     created  the  original  pathnames	for  files  are used and not the
	     canonicalised pathnames from the root directory.  Useful if  you've
	     got  things like automounters active that make directories with the
	     same non-canonical name have different canonical names on different
	     machines.

     -U/--use-write
	     Use the write() system call rather than the mmap() system call  for
	     audio  writing to the sound device.   This may fix some audio play-
	     back problems.

     -n/--mjpeg-buffers num
	     Number of MJPEG-buffers. Default is 32. Try changing this number if
	     you have many lost frames.

     -v/--verbose num
	     Verbosity level (0, 1 or 2)

ENVIRONMENT VARIABLES
     The following environment variables can be recognized by lavrec:

     LAV_VIDEO_DEV
	     The video device. Default is /dev/video

     LAV_AUDIO_DEV
	     The audio device. Default is /dev/dsp

SEARCHING AND EDITING
     lavplay can do more than simple plain playback. It is also intended  to  be
     controlled  using	commands sent via stdin from a front-end like glav(1) or
     similar, more sophisticated tools.  The most  significant	aspect	of  this
     functionality  is the ability to create edit list files giving the playback
     sequence of an editted version of the input video.  The edit list file  can
     be read by any of the mjpegtools(1) (including lavplay!) wherever an actual
     video  file  would be acceptable.	Such edit lists record only the original
     source file and start and stop frames of  the  components	of  the  editted
     video  editting  rather than the video itself.  As such editting leaves the
     original files unchanged and requires only tiny amounts  of  data-movement.
     The  drawback is that for the edit list to work the original files must re-
     main unchanged, and that interactive play may be jumpy due to the	playback
     sequence "skipping about" between different parts of the original video se-
     quence.

     If  a stand-alone consolidated versions of editted video is required it can
     be produced by running the lavtrans(1) utility on the edit list.

     Edit list files are plain text with a very simple syntax to allow easy man-
     ual editting using a text-editor or writing of scripted editting tools.

STDIN COMMANDS
     The commands accepted on standard input sre as follows (and can  of  course
     be entered directly by command-line junkies):

     +, -    Goes  to  next/previous  frame.  Only makes sense when the video is
	     paused.

     pN      Sets playback speed to N (N=..., -1, 0, 1, ...)

     a[01]   Enables/disables audio playback

     sN      if N is a number, this means to go to frame N. if N is prefixed  by
	     a + or -, this means to go N frames back- or forward.

     om editlist [N1 N2 [N3 N4]]
	     Opens  a movie or editlist. A second and third argument can specify
	     to only open a specific range of  frames  from  this  video  (N1=-1
	     means  whole  video). N3 and N4 can specify to show only a specific
	     range of frames from the frames which were just opened (useful  for
	     trimming).

     w[as] file
	     Save  the	current  editlist  (a) or the current selection (s) to a
	     file.

     q	     Quit lavplay.

     e[ou] N1 N2
	     Cuts (u) or copies (o) frames N1-N2 from the current editlist  into
	     an internal selection.

     ep      Pastes  the  contents of the selection into the current position in
	     the editlist.

     em N1 N2 N3
	     Moves frames N1-N2 to position N3 in the video.

     ed N1 N2
	     Deletes frames N1-N2 from the editlist.

     ea video N1 N2 N3
	     Adds frames N1-N2 of the video into  position  N3	within	the  ed-
	     itlist.  N1=-1 means to add the whole video.

     es N1 N2
	     Sets  the	current viewable frames within the whole video to N1-N2.
	     This is useful for trimming.

BUGS
     Editlists record absolute pathnames.  This more or less forces manual edit-
     ting of the pathnames in them if it is desired to move editlists and source
     video files.

     lavplay really ought to make a decent job of detecting  what  playback  op-
     tions  are feasible (on-screen hardware, video-out port hardware, software)
     and set the default playback mode appropriately.  Alas, it does not.

AUTHOR
     This man page was written by Ronald Bultje.
     If you have questions, remarks, problems or you just want	to  contact  the
     developers, the main mailing list for the MJPEG-tools is:
	 mjpeg-users@lists.sourceforge.net
     For more info, see our website at
	 http://mjpeg.sourceforge.net/

SEE ALSO
     mjpegtools(1), lavrec(1), glav(1)

MJPEG Tools Team		 6 December 2001		      lavplay(1)

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