Video::ivtv - Perl extension for using V4l2 in the ivtv perl scripts

       James A. Pattie <james at pcxperience dot com>

       The Video::ivtv module will provide helper methods for working with videodev2.h structures and making
       ioctl calls that have proven to be too difficult to create pack strings for in perl itself.

       This is not supposed to be an equivalent of the Video::Capture::V4l module which was created for
       videodev.h.

   EXPORT
       All functions and the variables section.

       @(driver, card, bus_info, version, capabilities) getCapabilities(fd)
             Returns the contents of the v4l2_capability structure.
             If the ioctl fails, then an empty list is returned.

       @(width,height) getResolution(fd)
             Pass in the file handle number using fileno($fd) and the
             width and height are returned in an array ref.

             If an error is encountered in the ioctl call, then width
             and height will = -1.

       int setResolution(fd, width, height)
             Specify the new width, height to set the capture to.
                   Returns undef if invalid resolution is specified.
             Returns a 1 if sucess, 0 if error from the actual code.

       int getStandard(fd)
             Returns the current video standard the card is using.

       int setStandard(fd, standard)
             Sets the video standard to what is specified (hex value).
             Returns 1 on success, 0 on error.

       @(index, id, name, frameperiod_numerator, frameperiod_denominator, framelines) enumerateStandard(fd,
       index)
             Returns the contents of the v4l2_standard structure for
             the specified index.  If the ioctl fails then index = -1.

       int getFrequency(fd, tuner)
             Returns the current frequency for the specified tuner
             or -1 if an ioctl error occured.  Returns undef on invalid
             parameters.

       int setFrequency(fd, tuner, freq)
             Sets the specified frequency on the specified tuner.
             Returns 1 on success, 0 on error.

       int getInput(fd)
             Returns the current input number starting from 0.
             Returns -1 if an error occured.

       int setInput(fd, input)
             Sets the input to the specified value.  input is a 0
             indexed value.  Returns 1 on success, 0 on error.

       @(index, name, type, audioset, tuner, std, status) enumerateInput(fd, index)
             Returns the contents of the v4l2_input structure for
             the specified index.  If the ioctl fails then index = -1.

       @(aspect, audio_bitmask, bframes, bitrate, bitrate_peak, dnr_mode, dnr_spatial, dnr_temporal, dnr_type,
       framerate, framespergop, gop_closure, pulldown, stream_type) getCodecInfo(fd)
             Returns the contents of the ivtv_ioctl_codec structure.
             If the ioctl fails then an empty list is returned.

             audio_bitmask is what audio used to be.

       int setCodecInfo(fd, aspect, audio_bitmask, bframes, bitrate, bitrate_peak, dnr_mode, dnr_spatial,
       dnr_temporal, dnr_type, framerate, framespergop, gop_closure, pulldown, stream_type)
             Sets the card to the specified codec related stuff.
             Returns 1 on success, 0 on error.

             audio_bitmask is what audio used to be.

       int setEndGOP(fd, end_gop)
             Sets the GOP_END flag to the specified value (1 or 0)
                   to instruct the driver to finish a recording with a
                   closed GOP.

                   Returns undef if end_gop < 0 or > 1.
                   Returns 1 on success, 0 on error.

       int stopEncoding(fd)
             Calls the VIDIOC_STREAMOFF ioctl to signal we want
                   to stop encoding (reading from the driver).

                   Returns 1 on success, 0 on error.

       Video::ivtv - Perl extension for using V4l2 in the ivtv perl scripts

       perl.

perl v5.40.1                                       2025-04-13                                          ivtv(3pm)

         use Video::ivtv;

         open(my $tuner, "</dev/video0") or die "Error opening /dev/video0! $!";

         my $tunerFD = fileno($tuner);  # the C functions need the file handle #.

         # initialize the Video::ivtv module
         my $ivtvObj = Video::ivtv->new();

         # get the current resolution
         my ($width, $height) = $ivtvObj->getResolution($tunerFD);

         # set the new resolution
         $ivtvObj->setResolution($tunerFD, 640, 480);

         close($tuner);

       %codecIndexes
             This contains the index names and their position in the
             ivtv_ioctl_codec structure as returned by getCodecInfo()
             and as expected by setCodecInfo().

       %capIndexes
             This contains the index names and their position in the
             v4l2_capability structure as returned by getCapabilities().