cysounddevice.buffer module

StreamBuffer class

StreamInputBuffer class

StreamOutputBuffer class

C-API

SampleBuffer

A buffering structure with preallocated memory for use in _stream_callback

BufferItem *items

Buffer array of BufferItem

Py_ssize_t length

Number of items to allocate

Py_ssize_t itemsize

Size in bytes per sample

Py_ssize_t item_length

Number of samples to allocate for each BufferItem (block size)

Py_ssize_t nchannels

Number of channels

Py_ssize_t write_index

Index of the next item to use for writing

Py_ssize_t read_index

Index of the next item to use for reading

BLOCK_t current_block

The current block of samples

int read_available

Number of items available to read from

int write_available

Number of items available to write to

BufferItem

A single item used to store data for SampleBuffer

SampleTime_s start_time

The time of the first sample in the item’s buffer, as reported by PortAudio

Py_ssize_t index

Index of the item within its parent SampleBuffer

Py_ssize_t length

Number of samples the item contains

Py_ssize_t itemsize

Size in bytes per sample

Py_ssize_t nchannels

Number of channels

Py_ssize_t total_size

The total size in bytes to allocate `` length * itemsize * nchannels ``

char *bfr

Pointer to the preallocated buffer

SampleBuffer* sample_buffer_create(SampleTime_s start_time, Py_ssize_t length, Py_ssize_t nchannels, Py_ssize_t itemsize)

Creates a SampleBuffer and child items (BufferItem), allocating all required char buffers.

void sample_buffer_destroy(SampleBuffer* bfr)

Deallocates the given SampleBuffer and all of its child items.

int sample_buffer_write(SampleBuffer* bfr, const void *data, Py_ssize_t length)

Copy the given data to the next available item in the given SampleBuffer. If no items are available to write (the buffer is full), no data is copied.

Returns 1 if successful

SampleTime_s* sample_buffer_read(SampleBuffer* bfr, char *data, Py_ssize_t length)

Copy data from the next available item into the given buffer.

Returns:

A SampleTime_s pointer to the BufferItem.start_time describing the source timing of the data. If no data is available, returns NULL.

SampleTime_s* sample_buffer_read_sf32(SampleBuffer* bfr, float[:, :] data)

Copy stream data from a SampleBuffer into a float array

Deinterleaves the stream and casts it to 32-bit float. A typed memoryview may be used.

The sample format must be paFloat32.

Returns:

A SampleTime_s pointer to the BufferItem.start_time describing the source timing of the data. If no data is available, returns NULL.