Module Flac.Encoder

module Encoder: sig .. end

Encode native FLAC data

Usage

A typical use of the FLAC encoder is the following:

 (* A function to write encoded data *)
 let write = (..a function of type write..) in
 (* Create the encoding callbacks *)
 let callbacks = Flac.Encoder.get_callbacks write in
 (* Define the parameters and comments *)
 let params = (..a value of type params ..) in
 let comments = [("title","FLAC encoding example")] in
 (* Create an encoder *)
 let enc = Flac.Encoder.create ~comments params callbacks in
 (* Encode data *)
 let data = (..a value of type float array array.. in 
  Flac.Encoder.process enc callbacks data ;
 (..repeat encoding process..)
 (* Close encoder *)
 Flac.Encoder.finish enc callbacks

Remarks:

Exceptions raised by the callbacks should be treated as fatal. The behaviour of the FLAC encoding library is unknown after interrupted by an exception.
Encoded data should have the same number of channels as specified in encoder's parameters and the same number of samples in each channels.
See FLAC documentation for informations about the callbacks. Note in particular that some information about encoded data such as md5 sum and total samples are only written when a seek callback is given.
Variant types for callbacks and encoder are used to make sure that different type of callbacks (generic, file, ogg) are always used with the corresponding decoder type.

Types

type 'a t

Type of an encoder.

type write = string -> unit

Type of a write callback

type 'a callbacks

Type of a set of callbacks

type generic

Generic type for an encoder

type params = {

	`channels : int;`
	`bits_per_sample : int;`
	`sample_rate : int;`
	`compression_level : int option;`
	`total_samples : int64 option;`

}

Type of encoding parameters

type comments = (string * string) list

(Vorbis) comments for encoding

Exceptions

exception Invalid_data

Raised when submiting invalid data to encode

Functions

val get_callbacks : ?seek:(int64 -> unit) ->
       ?tell:(unit -> int64) ->
       write -> generic callbacks

Create a set of encoding callbacks

val create : ?comments:comments ->
       params -> 'a callbacks -> 'a t

Create an encoder

val process : 'a t -> 'a callbacks -> float array array -> unit

Encode some data

val finish : 'a t -> 'a callbacks -> unit

Terminate an encoder. Causes the encoder to flush remaining encoded data. The encoder should not be used anymore afterwards.

Convenience

val from_s16le : string -> int -> float array array

Convert S16LE pcm data to an audio array for encoding WAV and raw PCM to flac.

module File: sig .. end

Encode to a local file