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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
               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 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
               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 playback 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 remain unchanged, and
       that interactive play  may  be  jumpy  due  to  the  playback  sequence
       "skipping   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
               editlist.  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)