c3d.Writer

class c3d.Writer(point_rate=480.0, analog_rate=0.0, point_scale=-1.0, point_units=u'mm ', gen_scale=1.0)

This class writes metadata and frames to a C3D file.

For example, to read an existing C3D file, apply some sort of data processing to the frames, and write out another C3D file:

>>> r = c3d.Reader(open('data.c3d', 'rb'))
>>> w = c3d.Writer()
>>> w.add_frames(process_frames_somehow(r.read_frames()))
>>> with open('smoothed.c3d', 'wb') as handle:
>>>     w.write(handle)
Parameters:
point_rate : float, optional

The frame rate of the data. Defaults to 480.

analog_rate : float, optional

The number of analog samples per frame. Defaults to 0.

point_scale : float, optional

The scale factor for point data. Defaults to -1 (i.e., “check the POINT:SCALE parameter”).

point_units : str, optional

The units that the point numbers represent. Defaults to 'mm  '.

gen_scale : float, optional

General scaling factor for data. Defaults to 1.
__init__(point_rate=480.0, analog_rate=0.0, point_scale=-1.0, point_units=u'mm ', gen_scale=1.0)

Set metadata for this writer.

Methods

__init__([point_rate, analog_rate, …]) Set metadata for this writer.
add_frames(frames) Add frames to this writer instance.
add_group(group_id, name, desc) Add a new parameter group.
check_metadata() Ensure that the metadata in our file is self-consistent.
first_frame()
get(group[, default]) Get a group or parameter.
get_bytes(key) Get a parameter value as a byte string.
get_float(key) Get a parameter value as a 32-bit float.
get_int16(key) Get a parameter value as a 16-bit signed integer.
get_int32(key) Get a parameter value as a 32-bit signed integer.
get_int8(key) Get a parameter value as an 8-bit signed integer.
get_string(key) Get a parameter value as a string.
get_uint16(key) Get a parameter value as a 16-bit unsigned integer.
get_uint32(key) Get a parameter value as a 32-bit unsigned integer.
get_uint8(key) Get a parameter value as an 8-bit unsigned integer.
last_frame()
parameter_blocks() Compute the size (in 512B blocks) of the parameter section.
write(handle) Write metadata and point + analog frames to a file handle.

Attributes

analog_labels
analog_rate
analog_used
point_labels
point_rate
point_scale
point_used
add_frames(frames)

Add frames to this writer instance.

Parameters:
frames : sequence of (point, analog) tuples

A sequence of frame data to add to the writer.
write(handle)

Write metadata and point + analog frames to a file handle.

Parameters:
handle : file

Write metadata and C3D motion frames to the given file handle. The writer does not close the handle.