avifilelib.rle module¶

Decoders for Microsoft RLE formats.

This package provides decoders capable of decoding frames encoded using the Microsoft RLE4 and RLE8 formats.

class avifilelib.rle.RLE4Decoder(width, height, colors)¶

Bases: avifilelib.rle.RLEDecoderBase

Decoder for RLE4 compression.

This class implements a decoder for the RLE4 compression algorithm.

Parameters:	width (int) – Width of the image to be decoded. height (int) – Height of the image to be decoded. colors (numpy.ndarray, dtype=uint8) – 16 x 3 of red, green, and blue values.

COMPRESSION = 2¶

decode_frame_buffer(buffer, size, keyframe=True)¶

Decode a frame from a bytes object.

Decodes a single frame from the data contained in buffer.

Parameters:	buffer (bytes) – A `bytes` object containing the frame data. size (int) – Size of the data in the buffer. keyframe (bool) – Indicates to the decoder that this chunk contains a key frame.
Returns:	A two dimensional array of dimensions height by width containing the resulting image.
Return type:	numpy.ndarray

class avifilelib.rle.RLE8Decoder(width, height, colors)¶

Bases: avifilelib.rle.RLEDecoderBase

Decoder for RLE8 compression.

This class implements a decoder for the RLE8 compression algorithm.

Parameters:	width (int) – Width of the image to be decoded. height (int) – Height of the image to be decoded. colors (numpy.ndarray, dtype=uint8) – 256 x 3 of red, green, and blue values.

COMPRESSION = 1¶

decode_frame_buffer(buffer, size, keyframe=True)¶

Decode a frame from a bytes object.

Decodes a single frame from the data contained in buffer.

Parameters:	buffer (bytes) – A `bytes` object containing the frame data. size (int) – Size of the data in the buffer. keyframe (bool) – Indicates to the decoder that this chunk contains a key frame.
Returns:	A two dimensional array of dimensions height by width containing the resulting image.
Return type:	numpy.ndarray

class avifilelib.rle.RLEDecoderBase(width, height, colors)¶

Bases: avifilelib.decoder.DecoderBase

Base class for RLE formats.

This class provides the foundation for run-length encoding decoders. Both the RLE4 and RLE8 formats require color paletes, and therefore this class accepts a color palate/table as an argument.

Parameters:	width (int) – Width of the image to be decoded. height (int) – Height of the image to be decoded. colors (numpy.ndarray, dtype=uint8) – N x 3 of red, green, and blue values, where N is 2^4 or 2^8 depending on the type of RLE compression.

COMPRESSION = (<BI_COMPRESSION.BI_RLE4: 2>, <BI_COMPRESSION.BI_RLE8: 1>)¶

colors¶: Get the color table.

classmethod for_avi_stream(stream_definition)¶

Attempts to find a decoder implementation for a stream.

Subclasses of RLEDecoderBase are selected by matching the value of COMPRESSION.

Returns:	A subclass of `RLEDecoderBase`.
Return type:	object