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