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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
       interactive 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 device.	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 con-
	       tained, 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 us-
	       ing 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.	 Basi-
	       cally,  you  almost  certainly  want this.  Disabling is	really
	       there for diagnostic purposes and not much else.

       -H/--H-offset num, -V/--V-offset	num
	       Horizontal (-H) and vertical (-V) offset	when  using  hardware-
	       playback.   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
	       using hardware onscreen playback	in non-fullscreen mode.

       --display :x.x
	       When using hardware fullsreen video playback (-pH),  this  set-
	       ting  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 directo-
	       ries 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  au-
	       dio playback problems.

       -n/--mjpeg-buffers num
	       Number  of MJPEG-buffers. Default is 32.	Try changing this num-
	       ber 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 as-
       pect 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 it-
       self.  As such editting leaves the original  files  unchanged  and  re-
       quires  only  tiny  amounts of data-movement.  The drawback is that for
       the edit	list to	work the original files	 must  remain  unchanged,  and
       that  interactive play may be jumpy due to the playback sequence	"skip-
       ping about" between different parts of the original video sequence.

       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
       manual 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
       editting	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
       options 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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