carriage Package

interface Module

class ebu_tt_live.carriage.interface.ICarriageMechanism

Bases: object

Basic interface for the carrige mechanisms

classmethod auto_register_impl(y)

class ebu_tt_live.carriage.interface.IConsumerCarriage

Bases: ebu_tt_live.carriage.interface.ICarriageMechanism

Carriage mechanism interface for consumer nodes.

classmethod auto_register_impl(y)

consumer_node

Node accessor

Returns:

on_new_data(data, **kwargs)

Implement protocol specific preprocessing here.

Parameters:kwargs – Extra parameters to send down

classmethod provides()

Data type provided

Returns:

register_consumer_node(node)

Register the consumer node in the carriage mechanism

Parameters:node – Returns:

class ebu_tt_live.carriage.interface.IProducerCarriage

Bases: ebu_tt_live.carriage.interface.ICarriageMechanism

Carriage mechanism interface for producer nodes.

classmethod auto_register_impl(y)

emit_data(data, **kwargs)

Implement protocol specific postprocessing here.

Parameters:

• kwargs – Extra parameters to send down
• data –

Returns:

classmethod expects()

Data type expected

Returns:

producer_node

Node accessor

Returns:

register_producer_node(node)

Register the producer node in the carriage mechanism

Parameters:node – The node to connect to.

resume_producing()

This makes sure that the producers can be pulled. This is good for timer or manual triggering

Returns:

base Module

class ebu_tt_live.carriage.base.AbstractCarriage

Bases: object

is_document(document)

class ebu_tt_live.carriage.base.AbstractCombinedCarriage

Bases: ebu_tt_live.carriage.base.AbstractConsumerCarriage, ebu_tt_live.carriage.base.AbstractProducerCarriage

classmethod auto_register_impl(y)

class ebu_tt_live.carriage.base.AbstractConsumerCarriage

Bases: ebu_tt_live.carriage.interface.IConsumerCarriage, ebu_tt_live.carriage.base.AbstractCarriage

classmethod auto_register_impl(y)

consumer_node

register_consumer_node(node)

Register the consumer node in the carriage mechanism

Parameters:node – Returns:

class ebu_tt_live.carriage.base.AbstractProducerCarriage

Bases: ebu_tt_live.carriage.interface.IProducerCarriage, ebu_tt_live.carriage.base.AbstractCarriage

classmethod auto_register_impl(y)

producer_node

register_producer_node(node)

Register the producer node in the carriage mechanism

Parameters:node – The node to connect to.

resume_producing()

This makes sure that the producers can be pulled. This is good for timer or manual triggering

Returns:

direct Module

class ebu_tt_live.carriage.direct.DirectCarriageImpl

Bases: ebu_tt_live.carriage.base.AbstractCombinedCarriage

classmethod auto_register_impl(y)

emit_data(data, **kwargs)

Implement protocol specific postprocessing here.

Parameters:

• kwargs – Extra parameters to send down
• data –

Returns:

on_new_data(data, **kwargs)

Implement protocol specific preprocessing here.

Parameters:kwargs – Extra parameters to send down

resume_producing()

This makes sure that the producers can be pulled. This is good for timer or manual triggering

Returns:

filesystem Module

class ebu_tt_live.carriage.filesystem.FilesystemConsumerImpl

Bases: ebu_tt_live.carriage.base.AbstractConsumerCarriage

This class is responsible for setting the document object from the xml and set its availability time. The document is then sent to the node.

classmethod auto_register_impl(y)

on_new_data(data, **kwargs)

Implement protocol specific preprocessing here.

Parameters:kwargs – Extra parameters to send down

class ebu_tt_live.carriage.filesystem.FilesystemProducerImpl(dirpath, file_name_pattern='{sequence_identifier}_{counter}.xml', message_file_name_pattern='{sequence_identifier}_msg_{counter}.xml', circular_buf_size=0, suppress_manifest=False)

Bases: ebu_tt_live.carriage.base.AbstractProducerCarriage

This class implements a carriage mechanism to output produced documents to the file system. Its constructor takes a mandatory argument : the path to the desired output folder. If the folder does not exist it will be created. Each document handled by this carriage implementation is written in an xml file in the output folder. Along with the xml files, a manifest_sequenceIdentifier.txt file is also written in the output folder. Each time an xml file is written, a line using the following format is added to the manifest :

availability_time,path_to_xml_file

The manifest file gives the availability time for each document along with the path to the corresponding document. The timeline used for the availability times is the same as the one used in the documents, indeed the carriage implementation uses the same clock (or time reference) as the node that produces the documents. The writing order and thus the reading order is from top to bottom. Please note that depending on the timebase used by the producer node time may loop (going to the next day). It can loop with ttp:timeBase=”clock” or ttp:timeBase=”smpte”, but not with ttp:timeBase=”media”. If the output folder already exists and it contains a manifest_sequenceIdentifier.txt file for the same document sequence, the last line of the existing manifest file is parsed to get the last used sequence number and the current sequence is set to start from the next sequence number.

classmethod auto_register_impl(y)

check_availability_time(sequence_identifier, time_base=None, clock_mode=None, availability_time=None)

Make sure we have a suitable timedelta value sent down from upstream as availability_time. If the value is None or unusable use the default clock to derive an availability time for the current document. (This does not check if the value is within valid range)

Parameters:

• sequence_identifier – remember default clock used per sequence
• time_base – document time base
• clock_mode – in clock timebase this parameter is needed
• availability_time – provided availability_time from upstream

Returns:

a valid availability_time (timedelta)

emit_data(data, sequence_identifier=None, sequence_number=None, time_base=None, availability_time=None, delay=None, clock_mode=None, **kwargs)

Implement protocol specific postprocessing here.

Parameters:

• kwargs – Extra parameters to send down
• data –

Returns:

resume_producing()

This makes sure that the producers can be pulled. This is good for timer or manual triggering

Returns:

class ebu_tt_live.carriage.filesystem.FilesystemReader(manifest_path, custom_consumer, do_tail)

Bases: object

This class is responsible for reading the manifest file and sending the corresponding availability times and xml file’s content to its _custom_consumer. Important note : the manifest file and the xml documents have to be in the same folder (it is the default behavior of the producer).

resume_reading()

ebu_tt_live.carriage.filesystem.timedelta_to_str_manifest(timed)

ebu_tt_live.carriage.filesystem.timestr_manifest_to_timedelta(timestr)

websocket Module

class ebu_tt_live.carriage.websocket.WebsocketConsumerCarriage

Bases: ebu_tt_live.carriage.base.AbstractConsumerCarriage

classmethod auto_register_impl(y)

on_new_data(data, **kwargs)

Implement protocol specific preprocessing here.

Parameters:kwargs – Extra parameters to send down

class ebu_tt_live.carriage.websocket.WebsocketProducerCarriage

Bases: ebu_tt_live.carriage.base.AbstractProducerCarriage

classmethod auto_register_impl(y)

emit_data(data, sequence_identifier='default', delay=None, **kwargs)

Implement protocol specific postprocessing here.

Parameters:

• kwargs – Extra parameters to send down
• data –

Returns:

register_backend_producer(producer)

resume_producing()

This makes sure that the producers can be pulled. This is good for timer or manual triggering

Returns: