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             * * * *    tvtime  0.9.1    * * * *


  tvtime is a high quality television application for use with video
capture cards.  tvtime processes the input from a capture card,
processes it, and displays it on a computer monitor or projector.

  tvtime supports:

  o   Deinterlaced output at full interlaced rate of 59.94 frames per
      second for NTSC source, or 50 frames per second for PAL sources.
      This gives smoothness of motion and high visual quality.

  o   Multiple deinterlacing algorithms for finding the optimal mode for
      the video content and available processor speed.

  o   16:9 aspect ratio mode for the highest available resolution when
      processing input from an external DVD player or digital satellite
      receiver.

  o   A super-slick on-screen-display for the complete television
      experience.



  Using tvtime
  


usage: ./tvtime [-as] [-I <sampling>] [-w <width>] [-d <device>
                [-i <input>] [-n <norm>] [-f <frequencies>] [-t <tuner>]
        -a        16:9 mode.
        -s        Print frame skip information (for debugging).
        -I        V4L input scanline sampling, defaults to 720.
        -w        Output window width, defaults to 800.
        -d        video4linux device (defaults to /dev/video0).
        -i        video4linux input number (defaults to 0).
        -c        Enable luma correction.
        -l        Luma correction value (defaults to 1.0).  Use of this implies -c.
        -n        The mode to set the tuner to: PAL, NTSC or SECAM.
                  (defaults to NTSC)
        -f        The channels you are receiving with the tuner
                  (defaults to us-cable).
                  Valid values are:
                          us-bcast
                          us-cable
                          us-cable-hrc
                          japan-bcast
                          japan-cable
                          europe-west
                          europe-east
                          italy
                          newzealand
                          australia
                          ireland
                          france
                          china-bcast
                          southafrica
                          argentina
                          canada-cable
                          australia-optus
        -t        The tuner number for this input (defaults to 0).


Notes and FAQ

1.  16:9 mode

  In 16:9 mode we stretch the output (for full resolution from
widescreen DVDs), simulating a 16:9 TV.  If you're using a hardware DVD
player, you should tell it that you have a 16:9 TV.  The output width
parameter is for the output window, the height is determined by the
aspect ratio (yeah, we assume square pixels for now).

2.  bttv kernel buffers

  Someone noted that if you have a few number of kernel buffers for your
bttv card, then they had problems.  I could not reproduce it.  I use
'modprobe bttv gbuffers=8' but even using 2 buffers seemed fine for me.
Using a large number (like 8) may suck since the audio sync may be too
off.  Let me know if you have problems.

3.  Luma correction and the bttv

  We do a mapping of the input luma values.  There are two reasons to do
this.  The first is that the values from bttv-based capture cards are
wrong, and so I correct for a hardware bug.  This means that quality on
non-bttv capture cards will suffer until I add a command-line option.
The second reason is to increase or decrease the brightness.  If the
display is too dark or too light, you may like what you get from values
like -l 1.3 or -l 0.8 or similar.  This applies a gamma correction curve
to the luminance channel, and will distort your colour, but maybe in a
way that you find improves your mood. :)

4.  Key bindings

  Luma correction  (must be enabled with the -c option)
  ---------------
  k              : decrease correction value by 0.1
  l              : increase correction value by 0.1

  Volume
  ------
  m              : toggle mute
  keypad +       : increase volume of tuner audio by 1%
  keypad -       : decrease volume of tuner audio by 1%

  Tuning
  ------
  keypad numbers : input a channel (station) to tune to on the keypad
                 : Note: you have to be relatively quick between number
                 :       presses. no more than half a second apart.
  up arrow       : go to next channel
  down arrow     : go to prev channel

  Misc
  ----
  f              : toggle fullscreen mode
  q or escape    : quit

5.  CPU usage

  tvtime takes alot of CPU, especially to get the full-framerate output.
nVidia's binary drivers, and I think the GATOS ATI drivers, have a very
efficient XVideo implementation that should help alot to get high
framerate on machines with capable video cards.  However, tvtime will
also need alot of CPU to generate the fully deinterlaced video stream.
I run happily on a P3-733 with a G400, and Doug runs even more happily
on a P3-900 with a Geforce 2 and nVidia's binary drivers.

  To run tvtime on a slower machine, try using a smaller sampling per
scanline from V4L.  -I 400 or -I 480 should save alot of time and still
give reasonable viewing quality.

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