Struct portaudio_rs::stream::Stream

pub struct Stream<'a, I: SampleType, O: SampleType> { /* fields omitted */ }

An object for an PortAudio stream

Streams can have an input type I and output type O.

Methods

impl<'a, T: SampleType> Stream<'a, T, T>

pub fn open_default(
    num_input_channels: u32,
    num_output_channels: u32,
    sample_rate: f64,
    frames_per_buffer: u64,
    callback: Option<Box<StreamCallback<'a, T, T>>>
) -> Result<Stream<'a, T, T>, PaError>

Constructs a stream using the default input and output devices

Arguments

• num_input_channels: Desired number of input channels
• num_output_channels: Desired number of output channels
• sample_rate: Sample rate of the stream
• frames_per_buffer: Number of frames per buffer. Use FRAMES_PER_BUFFER_UNSPECIFIED to let portaudio determine the optimal number.
• callback: Some(callback) which PortAudio will call to read/write the buffers, or None when using the read and write methods

impl<'a, I: SampleType, O: SampleType> Stream<'a, I, O>

pub fn open(
    input: Option<StreamParameters<I>>,
    output: Option<StreamParameters<O>>,
    sample_rate: f64,
    frames_per_buffer: u64,
    flags: StreamFlags,
    callback: Option<Box<StreamCallback<'a, I, O>>>
) -> Result<Stream<'a, I, O>, PaError>

Constructs a stream with the desired input and output specifications

Arguments

• input: Specification for the input channel, or None for an output-only stream
• output: Specification for the output channel, or None for an input-only stream
• sample_rate: Sample rate of the stream
• frames_per_buffer: Number of frames per buffer. Use FRAMES_PER_BUFFER_UNSPECIFIED to let portaudio determine the optimal number.
• flags: Additional flags for the behaviour of the stream
• callback: Some(callback) which PortAudio will call to read/write the buffers, or None when using the read and write methods

pub fn start(&self) -> PaResult

Starts the stream

pub fn stop(&self) -> PaResult

Stops the stream. It will block untill all audio has finished playing

pub fn abort(&self) -> PaResult

Stop stream immediately without waiting for the buffers to complete

pub fn is_stopped(&self) -> Result<bool, PaError>

Returns wether the stream is stopped

pub fn is_active(&self) -> Result<bool, PaError>

Returns wether the stream is active

pub fn num_read_available(&self) -> Result<u32, PaError>

Get the number of frames that can be read from the stream without waiting

pub fn num_write_available(&self) -> Result<u32, PaError>

Get the number of frames that can be written to the stream without waiting

pub fn write(&self, buffer: &[O]) -> PaResult

Write the given buffer to the stream. This function blocks

Possible Error codes:

• CanNotWriteToAnInputOnlyStream: when num_output_channels = 0
• BadBufferPtr: when buffer.len() is not a multiple of num_output_channels
• Some other error given by PortAudio

pub fn read(&self, frames: u32) -> Result<Vec<I>, PaError>

Reads the requested number of frames from the input devices. This function blocks until the whole buffer has been filled.

Will return CanNotReadFromAnOutputOnlyStream if num_input_channels = 0.

pub fn cpu_load(&self) -> f64

Returns the cpu load the stream callback consumes. This will return 0.0 if the stream uses blocking read/write, or if an error occured.

pub fn time(&self) -> Duration

Get the current timestamp of the stream

pub fn info(&self) -> Option<StreamInfo>

Get the actual latencies and sample rate

Returns None when the stream is invalid or an error occured

pub fn set_finished_callback(
    &mut self,
    finished_callback: Box<StreamFinishedCallback<'a>>
) -> PaResult

Set a callback which is to be called when the StreamCallback finishes

pub fn unset_finished_callback(&mut self) -> PaResult

Remove any previously attached finish callback

Trait Implementations

impl<'a, I: SampleType, O: SampleType> Drop for Stream<'a, I, O>

fn drop(&mut self)

Executes the destructor for this type.