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 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 (0) or SEC_MINI_B (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 <schmorp@schmorp.de>, http://home.schmorp.de/
Magnus Schmidt, eMail at http://www.27b-6.de/email.php