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Module Portaudio


module Portaudio: sig .. end
Bindings for the portaudio portable audio library.


Author(s): Samuel Mimram, Niki Yoshiuchi


Exceptions


exception Error of int
An error occured. In the future, this exception should be replaced by more specific exceptions. Use string_of_error to get a description of the error.
exception Unanticipated_host_error
An unanticipaced
val string_of_error : int -> string
Get a description of an error.
val get_last_host_error : unit -> int * string
Get the last errror which occured together with its description.

General


val get_version : unit -> int
Version of portaudio.
val get_version_string : unit -> string
Version of portaudio.
val init : unit -> unit
Initialize the portaudio library. Should be called before calling any other function.
val terminate : unit -> unit
Stop using the library. This function should be called before ending the program and no other portaudio function should be called after.

Host API



type host_api_info = {
   h_struct_version : int;
   h_host_api_type : int;
   h_name : string;
   h_device_count : int;
   h_default_input_device : int;
   h_default_output_device : int;
}
Host API Information
val get_host_api_count : unit -> int
Number of available host API.
val get_default_host_api : unit -> int
Index of the default host API.
val get_host_api_info : int -> host_api_info
Information on a host API

type device_info = {
   d_struct_version : int;
   d_name : string;
   d_host_api : int;
   d_max_input_channels : int;
   d_max_output_channels : int;
   d_default_low_input_latency : float;
   d_default_low_output_latency : float;
   d_default_high_input_latency : float;
   d_default_high_output_latency : float;
   d_default_sample_rate : float;
}
Device Information
val get_default_input_device : unit -> int
Default input device.
val get_default_output_device : unit -> int
Default output device.
val get_device_count : unit -> int
Number of available devices.
val get_device_info : int -> device_info
Information on device

Streams


type ('a, 'b) sample_format
The abstract type ('a, 'b) sample_format describes the OCaml type 'a and the underlying C type 'a used to represent the data being written to or read from a stream. This type is compatible with ('a, 'b) Bigarray.kind.
val format_int8 : (int, Bigarray.int8_signed_elt) sample_format
See Portaudio.format_float32.
val format_int16 : (int, Bigarray.int16_signed_elt) sample_format
See Portaudio.format_float32.
val format_int24 : (int32, Bigarray.int32_elt) sample_format
See Portaudio.format_float32.
val format_int32 : (int32, Bigarray.int32_elt) sample_format
See Portaudio.format_float32.
val format_float32 : (float, Bigarray.float32_elt) sample_format
The stream uses floats in the range of -1.,1. to represent audio data. The underlying type is a 32 bit float.

type ('a, 'b) stream_parameters = {
   channels : int;
   device : int;
   sample_format : ('a, 'b) sample_format;
   latency : float;
} 
type stream_flag 
type ('a, 'b, 'c, 'd) stream 
type ('a, 'b, 'c, 'd) callback = ('a, 'b, Bigarray.c_layout) Bigarray.Genarray.t ->
       ('c, 'd, Bigarray.c_layout) Bigarray.Genarray.t -> int -> int
The function signature of a callback. Callbacks only work with interleaved streams.
val open_stream : ('a, 'b) stream_parameters option ->
       ('c, 'd) stream_parameters option ->
       ?interleaved:bool ->
       float ->
       int ->
       ?callback:('a, 'b, 'c, 'd) callback ->
       stream_flag list -> ('a, 'b, 'c, 'd) stream
open_stream inparam outparam interleaved rate bufframes callback flags opens a new stream with input stream of format inparam, output stream of format outparam using interleaved or non-interleaved interleaved buffers at rate samples per second, with bufframes frames per buffer passed the callback function callback (0 means leave this choice to portaudio).
val open_default_stream : ?callback:('a, 'b, 'a, 'b) callback ->
       ?format:('a, 'b) sample_format ->
       ?interleaved:bool ->
       int -> int -> int -> int -> ('a, 'b, 'a, 'b) stream
open_default_stream callback format interleaved inchans outchans rate bufframes opens default stream with callback as callback function, handling samples in format format using interleaved or non-interleaved buffers interleaved with inchans input channels and outchans output channels at rate samples per seconds with handling buffers of size bufframes.
val close_stream : ('a, 'b, 'c, 'd) stream -> unit
Close a stream.
val start_stream : ('a, 'b, 'c, 'd) stream -> unit
Start a stream.
val stop_stream : ('a, 'b, 'c, 'd) stream -> unit
Stop a stream.
val abort_stream : ('a, 'b, 'c, 'd) stream -> unit
Abort a stream.
val sleep : int -> unit
Sleep.
val write_stream : ('a, 'b, 'c, 'd) stream -> 'c array array -> int -> int -> unit
Write to a stream.
val read_stream : ('a, 'b, 'c, 'd) stream -> 'a array array -> int -> int -> unit
Read from a stream.
val write_stream_ba : ('a, 'b, 'c, 'd) stream ->
       ('c, 'd, Bigarray.c_layout) Bigarray.Genarray.t -> int -> int -> unit
Write to a stream using a bigarray.
val read_stream_ba : ('a, 'b, 'c, 'd) stream ->
       ('a, 'b, Bigarray.c_layout) Bigarray.Genarray.t -> int -> int -> unit
Read from a stream using a bigarray.