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use std::{
ffi::c_void,
slice::{from_raw_parts, from_raw_parts_mut},
};
use oboe_sys as ffi;
use num_traits::FromPrimitive;
use super::{
AudioInputStreamSafe, AudioOutputStreamSafe, AudioStreamBuilderHandle, AudioStreamRef,
DataCallbackResult, Error, IsFrameType,
};
/**
* This trait defines a callback interface for:
*
* 1) moving data to/from an audio stream using `on_audio_ready`
* 2) being alerted when a stream has an error using `on_error_*` methods
*/
pub trait AudioInputCallback {
/**
* The sample type and number of channels for processing.
*
* Oboe supports only two sample types:
*
* - **i16** - signed 16-bit integer samples
* - **f32** - 32-bit floating point samples
*
* Oboe supports only mono and stereo channel configurations.
*/
type FrameType: IsFrameType;
/**
* This will be called when an error occurs on a stream or when the stream is disconnected.
*
* Note that this will be called on a different thread than the onAudioReady() thread.
* This thread will be created by Oboe.
*
* The underlying stream will already be stopped by Oboe but not yet closed.
* So the stream can be queried.
*
* Do not close or delete the stream in this method because it will be
* closed after this method returns.
*/
fn on_error_before_close(
&mut self,
_audio_stream: &mut dyn AudioInputStreamSafe,
_error: Error,
) {
}
/**
* This will be called when an error occurs on a stream or when the stream is disconnected.
* The underlying AAudio or OpenSL ES stream will already be stopped AND closed by Oboe.
* So the underlying stream cannot be referenced.
* But you can still query most parameters.
*
* This callback could be used to reopen a new stream on another device.
* You can safely delete the old AudioStream in this method.
*/
fn on_error_after_close(
&mut self,
_audio_stream: &mut dyn AudioInputStreamSafe,
_error: Error,
) {
}
/**
* A buffer is ready for processing.
*
* For an output stream, this function should render and write `num_frames` of data
* in the stream's current data format to the audioData buffer.
*
* For an input stream, this function should read and process `num_frames` of data
* from the audioData buffer.
*
* The audio data is passed through the buffer. So do NOT call read() or
* write() on the stream that is making the callback.
*
* Note that numFrames can vary unless AudioStreamBuilder::setFramesPerCallback()
* is called.
*
* Also note that this callback function should be considered a "real-time" function.
* It must not do anything that could cause an unbounded delay because that can cause the
* audio to glitch or pop.
*
* These are things the function should NOT do:
*
* - allocate memory
* - any file operations such as opening, closing, reading or writing
* - any network operations such as streaming
* - use any mutexes or other blocking synchronization primitives
* - sleep
* - stop or close stream
* - read or write on stream which invoked it
*
* The following are OK to call from the data callback:
*
* - stream.get_*()
*
* If you need to move data, eg. MIDI commands, in or out of the callback function then
* we recommend the use of non-blocking techniques such as an atomic FIFO.
*/
fn on_audio_ready(
&mut self,
audio_stream: &mut dyn AudioInputStreamSafe,
audio_data: &[<Self::FrameType as IsFrameType>::Type],
) -> DataCallbackResult;
}
/**
* This trait defines a callback interface for:
*
* 1) moving data to/from an audio stream using `on_audio_ready`
* 2) being alerted when a stream has an error using `on_error_*` methods
*/
pub trait AudioOutputCallback {
/**
* The sample type and number of channels for processing.
*
* Oboe supports only two sample types:
*
* - **i16** - signed 16-bit integer samples
* - **f32** - 32-bit floating point samples
*
* Oboe supports only mono and stereo channel configurations.
*/
type FrameType: IsFrameType;
/**
* This will be called when an error occurs on a stream or when the stream is disconnected.
*
* Note that this will be called on a different thread than the onAudioReady() thread.
* This thread will be created by Oboe.
*
* The underlying stream will already be stopped by Oboe but not yet closed.
* So the stream can be queried.
*
* Do not close or delete the stream in this method because it will be
* closed after this method returns.
*/
fn on_error_before_close(
&mut self,
_audio_stream: &mut dyn AudioOutputStreamSafe,
_error: Error,
) {
}
/**
* This will be called when an error occurs on a stream or when the stream is disconnected.
* The underlying AAudio or OpenSL ES stream will already be stopped AND closed by Oboe.
* So the underlying stream cannot be referenced.
* But you can still query most parameters.
*
* This callback could be used to reopen a new stream on another device.
* You can safely delete the old AudioStream in this method.
*/
fn on_error_after_close(
&mut self,
_audio_stream: &mut dyn AudioOutputStreamSafe,
_error: Error,
) {
}
/**
* A buffer is ready for processing.
*
* For an output stream, this function should render and write numFrames of data
* in the stream's current data format to the audioData buffer.
*
* For an input stream, this function should read and process numFrames of data
* from the audioData buffer.
*
* The audio data is passed through the buffer. So do NOT call read() or
* write() on the stream that is making the callback.
*
* Note that numFrames can vary unless AudioStreamBuilder::set_frames_per_callback()
* is called.
*
* Also note that this callback function should be considered a "real-time" function.
* It must not do anything that could cause an unbounded delay because that can cause the
* audio to glitch or pop.
*
* These are things the function should NOT do:
*
* - allocate memory
* - any file operations such as opening, closing, reading or writing
* - any network operations such as streaming
* - use any mutexes or other blocking synchronization primitives
* - sleep
* - stop or close stream
* - read or write on stream which invoked it
*
* The following are OK to call from the data callback:
*
* - stream.get_*()
*
* If you need to move data, eg. MIDI commands, in or out of the callback function then
* we recommend the use of non-blocking techniques such as an atomic FIFO.
*/
fn on_audio_ready(
&mut self,
audio_stream: &mut dyn AudioOutputStreamSafe,
audio_data: &mut [<Self::FrameType as IsFrameType>::Type],
) -> DataCallbackResult;
}
pub(crate) fn set_input_callback<T: AudioInputCallback>(
builder: &mut AudioStreamBuilderHandle,
callback: T,
) {
let callback = Box::into_raw(Box::new(callback));
// SAFETY: `callback` has the same type as the first argument of each function, and each
// function follows the C ABI.
unsafe {
ffi::oboe_AudioStreamBuilder_setCallback(
&mut **builder as *mut ffi::oboe_AudioStreamBuilder,
callback.cast(),
Some(drop_context::<T>),
Some(on_audio_ready_input_wrapper::<T>),
Some(on_error_before_close_input_wrapper::<T>),
Some(on_error_after_close_input_wrapper::<T>),
);
}
}
pub(crate) fn set_output_callback<T: AudioOutputCallback>(
builder: &mut AudioStreamBuilderHandle,
callback: T,
) {
let callback = Box::new(callback);
let callback = Box::into_raw(callback);
// SAFETY: `callback` has the same type as the first argument of each function, and each
// function follows the C ABI.
unsafe {
ffi::oboe_AudioStreamBuilder_setCallback(
&mut **builder as *mut ffi::oboe_AudioStreamBuilder,
callback.cast(),
Some(drop_context::<T>),
Some(on_audio_ready_output_wrapper::<T>),
Some(on_error_before_close_output_wrapper::<T>),
Some(on_error_after_close_output_wrapper::<T>),
);
}
}
unsafe extern "C" fn drop_context<T>(context: *mut c_void) {
let context = Box::from_raw(context as *mut T);
drop(context);
}
unsafe extern "C" fn on_error_before_close_input_wrapper<T: AudioInputCallback>(
context: *mut c_void,
audio_stream: *mut ffi::oboe_AudioStream,
error: ffi::oboe_Result,
) {
let mut audio_stream = AudioStreamRef::wrap_raw(&mut *audio_stream);
let callback = &mut *(context as *mut T);
callback.on_error_before_close(&mut audio_stream, FromPrimitive::from_i32(error).unwrap());
}
unsafe extern "C" fn on_error_after_close_input_wrapper<T: AudioInputCallback>(
context: *mut c_void,
audio_stream: *mut ffi::oboe_AudioStream,
error: ffi::oboe_Result,
) {
let mut audio_stream = AudioStreamRef::wrap_raw(&mut *audio_stream);
let callback = &mut *(context as *mut T);
callback.on_error_after_close(&mut audio_stream, FromPrimitive::from_i32(error).unwrap());
}
unsafe extern "C" fn on_audio_ready_input_wrapper<T: AudioInputCallback>(
context: *mut c_void,
audio_stream: *mut ffi::oboe_AudioStream,
audio_data: *mut c_void,
num_frames: i32,
) -> ffi::oboe_DataCallbackResult {
let mut audio_stream = AudioStreamRef::wrap_raw(&mut *audio_stream);
let audio_data = from_raw_parts(
audio_data as *const <T::FrameType as IsFrameType>::Type,
num_frames as usize,
);
let callback = &mut *(context as *mut T);
callback.on_audio_ready(&mut audio_stream, audio_data) as i32
}
unsafe extern "C" fn on_error_before_close_output_wrapper<T: AudioOutputCallback>(
context: *mut c_void,
audio_stream: *mut ffi::oboe_AudioStream,
error: ffi::oboe_Result,
) {
let mut audio_stream = AudioStreamRef::wrap_raw(&mut *audio_stream);
let callback = &mut *(context as *mut T);
callback.on_error_before_close(&mut audio_stream, FromPrimitive::from_i32(error).unwrap());
}
unsafe extern "C" fn on_error_after_close_output_wrapper<T: AudioOutputCallback>(
context: *mut c_void,
audio_stream: *mut ffi::oboe_AudioStream,
error: ffi::oboe_Result,
) {
let mut audio_stream = AudioStreamRef::wrap_raw(&mut *audio_stream);
let callback = &mut *(context as *mut T);
callback.on_error_after_close(&mut audio_stream, FromPrimitive::from_i32(error).unwrap());
}
unsafe extern "C" fn on_audio_ready_output_wrapper<T: AudioOutputCallback>(
context: *mut c_void,
audio_stream: *mut ffi::oboe_AudioStream,
audio_data: *mut c_void,
num_frames: i32,
) -> ffi::oboe_DataCallbackResult {
let mut audio_stream = AudioStreamRef::wrap_raw(&mut *audio_stream);
let audio_data = from_raw_parts_mut(
audio_data as *mut <T::FrameType as IsFrameType>::Type,
num_frames as usize,
);
let callback = &mut *(context as *mut T);
callback.on_audio_ready(&mut audio_stream, audio_data) as i32
}