AMBE vocoder

Modules
	AMBE vocoder - internal API

Files
file	codec.h
	Osmocom GMR-1 AMBE vocoder header.
file	codec.c
	Osmocom GMR-1 AMBE vocoder public API implementation.

Data Structures
struct	gmr1_codec
	Structure for GMR1 codec state. More...

Functions
struct gmr1_codec *	gmr1_codec_alloc (void)
	Allocates and inits a codec object. More...
void	gmr1_codec_release (struct gmr1_codec *codec)
	Release a codec object created by gmr1_codec_alloc. More...
int	gmr1_codec_decode_frame (struct gmr1_codec *codec, int16_t *audio, int N, const uint8_t *frame, int bad)
	Decodes an AMBE frame to audio. More...
int	gmr1_codec_decode_dtx (struct gmr1_codec *codec, int16_t *audio, int N)
	Generates audio for DTX period. More...

Detailed Description

Function Documentation

gmr1_codec_alloc()

struct gmr1_codec * gmr1_codec_alloc

(

void

)

Allocates and inits a codec object.

Returns

A newly allocated codec, to be freed with gmr1_codec_release

References ambe_decode_init(), and gmr1_codec::dec.

gmr1_codec_decode_dtx()

int gmr1_codec_decode_dtx	(	struct gmr1_codec *	codec,
		int16_t *	audio,
		int	N
	)

Generates audio for DTX period.

Parameters

[in]	codec	Codec object
[out]	audio	Output audio buffer
[in]	N	number of audio samples to produce (152..168)

References ambe_decode_dtx(), and gmr1_codec::dec.

gmr1_codec_decode_frame()

int gmr1_codec_decode_frame	(	struct gmr1_codec *	codec,
		int16_t *	audio,
		int	N,
		const uint8_t *	frame,
		int	bad
	)

Decodes an AMBE frame to audio.

Parameters

[in]	codec	Codec object
[out]	audio	Output audio buffer
[in]	N	number of audio samples to produce (152..168)
[in]	frame	Frame data (10 bytes = 80 bits)
[in]	bad	Bad Frame Indicator. Set to 1 if frame is corrupt

Returns

0 for success. Negative error code otherwise.

References ambe_decode_frame(), and gmr1_codec::dec.

gmr1_codec_release()

void gmr1_codec_release

(

struct gmr1_codec *

codec

)

Release a codec object created by gmr1_codec_alloc.

Parameters

[in]

codec

The codec object to release

References ambe_decode_fini(), and gmr1_codec::dec.