Package: np-rw-buffer
This library was created to help store audio data in a numpy array. It allows for writing lists and numpy arrays into a circular buffer. You can read the data from the buffer with overlap to perform smooth FFTs.
The buffer is a wrapper around a numpy ndarray. It contains a start and end position to keep track of where to read and write the data.Main Functions:clear() - Clear the length, start, and end indexesget_data() - Return a copy of the data without moving indexesset_data(data) - Set the data and change the shape of the buffer to this data shapewrite(data, error) - Write data into the buffer and move the end indexread(amount) - Read data from the buffer and move the start index. If the amount is greater that what is in the buffer return a 0 length bufferExtra Functions to help with the start and end pointers:expanding_write(data, error) - Write data into the buffer. If the data is larger than the buffer expand the buffergrowing_write(data) - Write data into the buffer if there is not enough space make the buffer largerwrite_value(value, length, error=True, move_start=True) - Write a value into the buffer for the given length. This is more efficient then creating and writing an array of a single value.write_zeros(length, error=True, move_start=True) - Write Zeros for the given length. This is more efficient then creating and writing an array of zeros.read_remaining(amount) - Read the amount or read all of the data available to readread_overlap(amount, increment) - Read the amount of data given, but only increment the start index by the increment amount. This makes the next read, read some duplicate data (hence overlap)Buffer Control Functions:maxsize - (property) change the amount of samples that can be heldcolumns - (property) Number of columns that the array contains (shape[1])shape - (property) Change the shape of the bufferdtype - (property) Change the data type for the numpy bufferget_indexes(start, length) - Return a list of indexes for reading and writing (this makes the buffer circular)move_start(amount, error) - Move the start index (read)move_end(amount, error) - Move the end index (write)get_available_space() - return the amount of data that the buffer can still holdExample - simple exampleSimple reading and writing. See test_buffer for tests and usage.importnumpyasnpimportnp_rw_bufferbuffer=np_rw_buffer.RingBuffer(10)buffer.write(np.arange(5))r=buffer.read(4)assertnp.all(r==np.arange(4).reshape((-1,1)))# Not enough data, don't read anything (use read_remaining or get_data)d=np.arange(5).reshape((-1,1))buffer.write(d)r=buffer.read(10)assertlen(r)==0assertlen(buffer)==6r=buffer.read()assertlen(r)==6assertnp.all(r==np.vstack((d[-1:],d)))buffer.write(np.arange(6))# buffer.write(np.arange(5))  # Raises an OverflowErrorbuffer.write(np.arange(5),False)Example - AudioFramingBufferThe AudioFramingBuffer is slightly different from the RingBuffer. It has a sample_rate, seconds, and buffer_delay.It’s main differences are how it reads and writes. The start and end pointers are completely different and decoupled.
The start pointer can underrun the end pointer and back fills with 0’s. The end pointer can overrun the start pointer.importnumpyasnpfromnp_rw_bufferimportAudioFramingBufferbuffer=AudioFramingBuffer(2000,1)buffer.write(np.array([(i,)foriinrange(10)]))# Buffer: [(read ptr)0, 1, 2, 3, 4, 5, 6, 7, 8, 9, (write ptr) 0, 0, 0, 0, 0]assertbuffer._end==10assertbuffer._start==0# [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, (write ptr) 0, 0, 0, 0, 0] (read ptr at end)assertnp.all(buffer.read(15)==np.array([0,1,2,3,4,5,6,7,8,9,0,0,0,0,0]).reshape((-1,1)))assertbuffer._start==15assertbuffer._end==10buffer.write(np.array([(i,)foriinrange(10)]))# This will write in the position after 19# Buffer: [0, 0, 0, 0, 0, 0, 0, 0, 0, (was 9) 0, 0, 1, 2, 3, 4, (read ptr) 5, 6, 7, 8, 9] (write ptr at end)assertbuffer._end==20assertbuffer._start==15# [5, 6, 7, 8, 9, (write ptr) 0, 0, 0, 0, 0] (read ptr at end)assertnp.all(buffer.read(10)==np.array([5,6,7,8,9,0,0,0,0,0]).reshape((-1,1)))