Descriptor of a translator. More...

#include <translate.h>

Collaboration diagram for ast_translator:

Data Fields
int	active
int	buf_size
	size of outbuf, in bytes. Mandatory. The wrapper code will also allocate an AST_FRIENDLY_OFFSET space before.
int	buffer_samples
	size of outbuf, in samples. Leave it 0 if you want the framein callback deal with the frame. Set it appropriately if you want the code to checks if the incoming frame fits the outbuf (this is e.g. required for plc).
int	comp_cost
int	desc_size
void(*	destroy )(struct ast_trans_pvt *pvt)
int	dst_fmt_index
struct ast_format	dst_format
int(*	framein )(struct ast_trans_pvt pvt, struct ast_frame in)
struct ast_frame (	frameout )(struct ast_trans_pvt *pvt)
struct {
struct ast_translator * next
}	list
struct ast_module *	module
char	name [80]
int	native_plc
int(*	newpvt )(struct ast_trans_pvt *)
struct ast_frame (	sample )(void)
int	src_fmt_index
struct ast_format	src_format
int	table_cost

Detailed Description

Descriptor of a translator.

Name, callbacks, and various options related to run-time operation (size of buffers, auxiliary descriptors, etc).

A codec registers itself by filling the relevant fields of a structure and passing it as an argument to ast_register_translator(). The structure should not be modified after a successful registration, and its address must be used as an argument to ast_unregister_translator().

As a minimum, a translator should supply name, srcfmt and dstfmt, the required buf_size (in bytes) and buffer_samples (in samples), and a few callbacks (framein, frameout, sample). The outbuf is automatically prepended by AST_FRIENDLY_OFFSET spare bytes so generic routines can place data in there.

Note, the translator is not supposed to do any memory allocation or deallocation, nor any locking, because all of this is done in the generic code.

Translators using generic plc (packet loss concealment) should supply a non-zero plc_samples indicating the size (in samples) of artificially generated frames and incoming data. Generic plc is only available for dstfmt = SLINEAR

Definition at line 135 of file translate.h.

Field Documentation

int active

Whether this translator should be used or not

Definition at line 180 of file translate.h.

Referenced by __ast_register_translator(), ast_translator_activate(), ast_translator_deactivate(), and matrix_rebuild().

int buf_size

size of outbuf, in bytes. Mandatory. The wrapper code will also allocate an AST_FRIENDLY_OFFSET space before.

Definition at line 173 of file translate.h.

Referenced by __ast_register_translator(), dahdi_decoder_frameout(), dahdi_encoder_frameout(), lintospeex_frameout(), load_module(), newpvt(), and register_translator().

int buffer_samples

size of outbuf, in samples. Leave it 0 if you want the framein callback deal with the frame. Set it appropriately if you want the code to checks if the incoming frame fits the outbuf (this is e.g. required for plc).

Definition at line 168 of file translate.h.

Referenced by framein(), load_module(), and register_translator().

int comp_cost

Cost value associated with this translator based on computation time. This cost value is computed based on the time required to translate sample data.

Definition at line 142 of file translate.h.

Referenced by __ast_register_translator(), generate_computational_cost(), and matrix_rebuild().

int desc_size

size of private descriptor in pvt->pvt, if any

Definition at line 175 of file translate.h.

Referenced by load_module(), newpvt(), and register_translator().

void(* destroy)(struct ast_trans_pvt *pvt)

cleanup private data, if needed (often unnecessary).

Definition at line 157 of file translate.h.

Referenced by destroy(), load_module(), and register_translator().

int dst_fmt_index

index of the destination format in the matrix table