pyvrs.filter module

class pyvrs.filter.FilteredVRSReader(reader: BaseVRSReader, record_filter: RecordFilter)

Bases: BaseVRSReader, ABC

FilteredVRSReader represents subset of VRSReader after applying filter. This class essentially has the exact same methods as VRSReader but operates against subset of the file. Note that you can’t re-filter an already filtered VRSReader.

property file_tags: Mapping[str, str]

Return a dict of all file tags present in this VRS file.

Returns:

{<tag>: <value>}

Return type:

Dictionary of all file tags

find_stream(recordable_type_id: int, tag_name: str, tag_value: str) → str

Find stream matching recordable type and tag, and return its stream id. This call isn’t affected by the filter.

Parameters:

• recordable_type_id – stream_id is <recordable_type_id>-<instance_id>

• tag_name – tag name that you are interested in

• tag_value – tag value that you are interested in

Returns:

Stream ID that starts with recordable_type_id and has a given tag pair.

find_streams(recordable_type_id: int, flavor: str = '') → List[str]

Find streams matching recordable type and flavor, and return sets of stream ids. This call isn’t affected by the filter.

Parameters:

• recordable_type_id – stream_id is <recordable_type_id>-<instance_id>

• tag_name – tag name that you are interested in

• tag_value – tag value that you are interested in

Returns:

A set of stream IDs that start with recordable_type_id and has a given flavor.

get_estimated_frame_rate(stream_id: str) → float

Get the estimated frame rate for the given stream_id.

Parameters:

stream_id – stream_id that you are interested in.

Returns:

The estimated frame rate.

get_record_index_by_time(stream_id: str, timestamp: float, epsilon: float | None = None, record_type: RecordType | None = None) → int

Get index in filtered records by timestamp.

Parameters:

• stream_id – stream_id that you are interested in.

• timestamp – timestamp that you are interested in.

• epsilon – Optional argument. If specified we search for record in range of (timestamp-epsilon)-(timestamp+epsilon) and returns the nearest record.

• record_type – Optional argument. If specified we search for record with the record_type.

get_records_count(stream_id: str, record_type: RecordType) → int

Get the number of records for the stream_id & record_type.

Parameters:

• stream_id – stream_id you are interested in.

• record_type – record type you are interested in.

Returns:

The number of records for stream_id & record type

get_stream_info(stream_id: str) → Mapping[str, str]

Get details about a stream.

Parameters:

stream_id – stream_id you are interested in.

Returns:

An information about the stream in a dictionary.

get_timestamp_for_index(index: int) → float

Get the timestamp corresponding to the given index.

Parameters:

index – the index for the record

Returns:

A timestamp corresponds to the index

get_timestamp_list() → List[float]

Get the list of timestamps corresponding to the given indices.

Parameters:

indices – the list of indices we want to get the timestamp.

Returns:

A list of timestamps correspond to the indices, if indices are None, we get the full timestamp list.

property max_filter_timestamp: float

The value of max_timestamp when user called filter method on VRSReader.

property max_timestamp: float

The timestamp for the last record that this reader is configured to read, given current filters. Return 0 if there are no record.

might_contain_audio(stream_id: str) → bool

Check if the given stream_id contains an audio data.

Parameters:

stream_id – stream_id that you are interested in.

Returns:

Based on the config record, return if the stream contains an audio data.

might_contain_images(stream_id: str) → bool

Check if the given stream_id contains an image data.

Parameters:

stream_id – stream_id that you are interested in.

Returns:

Based on the config record, return if the stream contains an image data.

property min_filter_timestamp: float

The value of min_timestamp when user called filter method on VRSReader.

property min_timestamp: float

The timestamp for the first record that this reader is configured to read, given current filters. Return 0 if there are no record.

property n_records: int

The number of records that this reader is configured to read, given current filters.

read_next_record(stream_id: str, record_type: str, index: int) → VRSRecord | None

Read the first record that matches stream_id and record_type and its index is greater or equal than given index.

Parameters:

• stream_id – stream_id that you are interested in.

• record_type – record_type that you are interested in.

• index – the absolute index in the file. Based on this index, try to find the previous record that matches stream_id & record_type

Returns:

VRSRecord if there is a record, otherwise None

read_prev_record(stream_id: str, record_type: str, index: int) → VRSRecord | None

Read the last record that matches stream_id and record_type and its index is smaller or equal than given index.

Parameters:

• stream_id – stream_id that you are interested in.

• record_type – record_type that you are interested in.

• index – the absolute index in the file. Based on this index, try to find the previous record that matches stream_id & record_type

Returns:

VRSRecord if there is a record, otherwise None

read_record_by_time(stream_id: str, timestamp: float, epsilon: float | None = None, record_type: RecordType | None = None) → VRSRecord

Read record by timestamp.

Parameters:

• stream_id – stream_id that you are interested in.

• timestamp – timestamp that you are interested in.

• epsilon – Optional argument. If specified we search for record in range of (timestamp-epsilon)-(timestamp+epsilon) and returns the nearest record.

• record_type – Optional argument. If specified we search for record with the record_type.

Returns:

VRSRecord corresponds to the stream_id & timestamp.

Raises:

• TimestampNotFoundError – If epsilon is not None and the record doesn’t exist within the time range.

• ValueError – If epsilon is None and the record isn’t found using lower_bound.

property record_types: Set[str]

The set of record types that this reader is configured to read, given current filters.

set_image_conversion(conversion: ImageConversion) → None

Set default image conversion policy, and clears any stream specific setting.

Parameters:

conversion – The image conversion you want to apply for all streams.

set_stream_image_conversion(stream_id: str, conversion: ImageConversion) → None

Set image conversion policy for a specific stream.

Parameters:

• stream_id – The stream_id you want to apply image conversion to.

• conversion – The image conversion you want to apply for a specific stream.

set_stream_type_image_conversion(recordable_type_id: str, conversion: ImageConversion) → int

Set image conversion policy for streams of a specific device type.

Parameters:

• recordable_type_id – The recordable_type_id you want to apply image conversion to. If you specify 1000, streams with id 1000-* are the targets.

• conversion – The image conversion you want to apply for a specific stream.

Returns:

The number of streams affected.

property stream_ids: Set[str]

The set of stream ids that this reader is configured to read, given current filters.

property stream_tags: Mapping[str, Mapping[str, Any]]

Return a dict of all per-stream tags present in this VRS file.

Returns:

{<stream_id>: {<tag>: <value>}}

Return type:

Dictionary of all per-stream tags

class pyvrs.filter.RecordFilter(record_types: Set[str], stream_ids: Set[str], min_timestamp: float, max_timestamp: float)

Bases: object

RecordFilter represents a filter that’s applied to the VRS file.

max_timestamp: float

min_timestamp: float

record_types: Set[str]

stream_ids: Set[str]

class pyvrs.filter.SyncFilteredVRSReader(reader: BaseVRSReader, record_filter: RecordFilter)

Bases: FilteredVRSReader

Synchrnous version of FilteredVRSReader.