Linux::DVB(3) interface to (some parts of) the Linux DVB API

SYNOPSIS


use Linux::DVB;

DESCRIPTION

This module provides an interface to the Linux DVB API. It is a straightforward translation of the C API. You should read the Linux DVB API description to make any sense of this module. It can be found here: 

   http://www.linuxtv.org/docs/dvbapi/dvbapi.html

All constants from frontend.h and demux.h are exported by their C name and by default.

Noteworthy differences to the C API: unions and sub-structs are usually translated into flat perl hashes, i.e "struct.u.qam.symbol_rate" becomes "$struct->{symbol_rate}".

Noteworthy limitations of this module include: No interface to the video, audio and net devices. If you need this functionality bug the author.

Linux::DVB::Frontend CLASS

SYNOPSIS


my $fe = new Linux::DVB::Frontend $path, $writable;
my $fe = new Linux::DVB::Frontend
"/dev/dvb/adapter0/frontend0", 1;
$fe->fh; # filehandle
$fe->fd; # fileno
$fe->blocking (0); # or 1
$fe->{name}
$fe->{type}
$fe->frontend_info->{name}
$fe->status & FE_HAS_LOCK
print $fe->ber, $fe->snr, $fe->signal_strength, $fe->uncorrected;
my $tune = $fe->parameters;
$tune->{frequency};
$tune->{symbol_rate};

$fe->set (parameter => value, ...)
Sets frontend parameters. All values are stuffed into the "dvb_frontend_parameters" structure without conversion and passed to FE_SET_FRONTEND.

Returns true on success.

All modes: 

  frequency         =>
  inversion         =>

QPSK frontends: 

  symbol_rate       =>
  fec_inner         =>

QAM frontends: 

  symbol_rate       =>
  modulation        =>

QFDM frontends: 

  bandwidth         =>
  code_rate_HP      =>
  code_rate_LP      =>
  constellation     =>
  transmission_mode =>
$fe->parameters
Calls FE_GET_FRONTEND and returns a hash reference that contains the same keys as given to the "set" method.

Example: 

  Data::Dumper::Dumper $fe->get
  
  {
    frequency   => 426000000, # 426 Mhz
    inversion   => 0,         # INVERSION_OFF
    symbol_rate => 6900000,   # 6.9 MB/s
    modulation  => 3,         # QAM_64
  }
$ok = $fe->diseqc_reset_overload
If the bus has been automatically powered off due to power overload, this call restores the power to the bus. The call requires read/write access to the device. This call has no effect if the device is manually powered off. Not all DVB adapters support this call.
$ok = $fe->diseqc_voltage (13|18)
Set the DiSEqC voltage to either 13 or 18 volts.
$ok = $fe->diseqc_tone (1|0)
Enables (1) or disables (0) the DiSEqC continuous 22khz tone generation.
$ok = $fe->diseqc_send_burst (0|1)
Sends a 22KHz tone burst of type SEC_MINI_A \fIs0(0) or SEC_MINI_B \fIs0(1).
$ok = $fe->diseqc_cmd ($command)
Sends a DiSEqC command ($command is 3 to 6 bytes of binary data).
$reply = $fe->diseqc_reply ($timeout)
Receives a reply to a DiSEqC 2.0 command and returns it as a binary octet string 0..4 bytes in length (or "undef" in the error case).

Linux::DVB::Demux CLASS

SYNOPSIS


my $dmx = new Linux::DVB::Demux
"/dev/dvb/adapter0/demux0";
$fe->fh; # filehandle
$fe->fd; # fileno
$fe->blocking (1); # non-blocking is default
$dmx->buffer (16384);
$dmx->sct_filter ($pid, "filter", "mask", $timeout=0, $flags=DMX_CHECK_CRC);
$dmx->pes_filter ($pid, $input, $output, $type, $flags=0);
$dmx->start;
$dmx->stop;

Linux::DVB::Decode CLASS

SYNOPSIS


$si_decoded_hashref = Linux::DVB::Decode::si $section_data;

$hashref = Linux::DVB::Decode::si $section_data
Tries to parse the string inside $section_data as an SI table and return it as a hash reference. Only the first SI table will be returned as hash reference, and the $section_data will be modified in-place by removing the table data.

The way to use this function is to append new data to your $section_data and then call "Linux::DVB::Decode::si" in a loop until it returns "undef". Please ntoe, however, that the Linux DVB API will return only one table at a time from sysread, so you can safely assume that every sysread will return exactly one (or zero in case of errors) SI table.

Here is an example of what to expect: 

  {
    'segment_last_section_number' => 112,
    'table_id' => 81,
    'service_id' => 28129,
    'original_network_id' => 1,
    'section_syntax_indicator' => 1,
    'current_next_indicator' => 1,
    'events' => [
                  {
                    'running_status' => 0,
                    'start_time_hms' => 2097152,
                    'event_id' => 39505,
                    'free_CA_mode' => 0,
                    'start_time_mjd' => 53470,
                    'descriptors' => [
                                       {
                                         'event_name' => 'Nachrichten',
                                         'text' => '',
                                         'ISO_639_language_code' => 'deu',
                                         'type' => 77
                                       },
                                       {
                                         'programme_identification_label' => 337280,
                                         'type' => 105
                                       },
                                       {
                                         'raw_data' => '22:0010.04#00',
                                         'type' => 130
                                       }
                                     ],
                    'duration' => 1280
                  },
                  {
                    'running_status' => 0,
                    'start_time_hms' => 2098432,
                    'event_id' => 39506,
                    'free_CA_mode' => 0,
                    'start_time_mjd' => 53470,
                    'descriptors' => [
                                       {
                                         'event_name' => 'SR 1 - Nachtwerk',
                                         'text' => '',
                                         'ISO_639_language_code' => 'deu',
                                         'type' => 77
                                       },
                                       {
                                         'programme_identification_label' => 337285,
                                         'type' => 105
                                       },
                                       {
                                         'raw_data' => '22:0510.04#00',
                                         'type' => 130
                                       }
                                     ],
                    'duration' => 87296
                  }
                ],
    'last_table_id' => 81,
    'section_number' => 112,
    'last_section_number' => 176,
    'version_number' => 31,
    'transport_stream_id' => 1101
  }
$text = Linux::DVB::Decode::text $data
Converts text found in DVB si tables into perl text. Only iso-8859-1..-11 and UTF-16 is supported, other encodings (big5 etc. is not. Bug me if you need this).
%Linux::DVB::Decode::nibble_to_genre
A two-level hash mapping genre nibbles to genres, e.g. 

   $Linux::DVB::Decode::nibble_to_genre{7}{6}
   => 'film/cinema'
($sec,$min,$hour) = Linux::DVB::Decode::time $hms
($mday,$mon,$year) = Linux::DVB::Decode::date $mjd
($sec,$min,$hour,$mday,$mon,$year) = Linux::DVB::Decode::datetime $mjd, $hms
$sec = Linux::DVB::Decode::time_linear $hms
$sec = Linux::DVB::Decode::datetime_linear $mjd, $hms
Break down a ``DVB time'' (modified julian date + bcd encoded seconds) into it's components (non-"_linear") or into a seconds count ("_linear" variants) since the epoch ("datetime_linear") or the start of the day ("time_linear").

The format of the returns value of the date and datetime functions is not compatible with "Time::Local". Use the "_linear" functions instead.

Example: 

   my $time = Linux::DVB::Decode::datetime_linear $mjd, $hms
   printf "Starts at %s\n",
      POSIX::strftime "%Y-%m-%d %H:%M:%S",
         localtime $time;

AUTHORS

 Marc Lehmann <[email protected]>, http://home.schmorp.de/
 Magnus Schmidt, eMail at http://www.27b-6.de/email.php

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