/ 
Linux-DVB-0.3
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/ Linux::DVB

NAME

Linux::DVB - 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 way to set the frequency or diseqc. 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       =>
fec_inner         =>
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
  fec_inner   => 0,         # FEC_NONE
  modulation  => 3,         # QAM_64
}

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,$mday,$mon,$year) = Linux::DVB::Decode::time $mjd, $time

Break down a "DVB time" (modified julian date + bcd encoded seconds) into it's components in UTC (i.e. use Time::Local::timegm to convert to UNIX time).

AUTHORS

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