Enhanced Variable Rate Codec, Service Option 3 decoder. More...

#include "libavutil/mathematics.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "evrcdata.h"
#include "acelp_vectors.h"
#include "lsp.h"

Go to the source code of this file.

Data Structures
struct	EVRCAFrame
	EVRC-A unpacked data frame. More...

struct	EVRCContext

struct	PfCoeff

Macros
#define	MIN_LSP_SEP (0.05 / (2.0 * M_PI))

#define	MIN_DELAY 20

#define	MAX_DELAY 120

#define	NB_SUBFRAMES 3

#define	SUBFRAME_SIZE 54

#define	FILTER_ORDER 10

#define	ACB_SIZE 128

Enumerations
enum	evrc_packet_rate { RATE_ERRS = -1, SILENCE, RATE_QUANT, RATE_QUARTER, RATE_HALF, RATE_FULL }

Functions
static void	unpack_frame (EVRCContext *e)
	Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT.

static evrc_packet_rate	buf_size2bitrate (const int buf_size)

static evrc_packet_rate	determine_bitrate (AVCodecContext avctx, int buf_size, const uint8_t **buf)
	Determine the bitrate from the frame size and/or the first byte of the frame.

static void	warn_insufficient_frame_quality (AVCodecContext avctx, const char message)

static av_cold int	evrc_decode_init (AVCodecContext *avctx)
	Initialize the speech codec according to the specification.

static int	decode_lspf (EVRCContext *e)
	Decode the 10 vector quantized line spectral pair frequencies from the LSP transmission codes of any bitrate and check for badly received packets.

static void	interpolate_lsp (float ilsp, const float lsp, const float *prev, int index)

static void	interpolate_delay (float *dst, float current, float prev, int index)

static void	decode_predictor_coeffs (const float ilspf, float ilpc)

static void	bl_intrp (EVRCContext e, float ex, float delay)

static void	acb_excitation (EVRCContext e, float excitation, float gain, const float delay[3], int length)

static void	decode_8_pulses_35bits (const uint16_t fixed_index, float cod)

static void	decode_3_pulses_10bits (uint16_t fixed_index, float *cod)

static void	fcb_excitation (EVRCContext e, const uint16_t codebook, float *excitation, float pitch_gain, int pitch_lag, int subframe_size)

static void	synthesis_filter (const float in, const float filter_coeffs, float memory, int buffer_length, float samples)
	Synthesis of the decoder output signal.

static void	bandwidth_expansion (float coeff, const float inbuf, float gamma)

static void	residual_filter (float output, const float input, const float coef, float memory, int length)

static void	postfilter (EVRCContext e, float in, const float coeff, float out, int idx, const struct PfCoeff *pfc, int length)

static void	frame_erasure (EVRCContext e, float samples)

static int	evrc_decode_frame (AVCodecContext avctx, void data, int got_frame_ptr, AVPacket avpkt)

Variables
static struct PfCoeff	postfilter_coeffs [5]

AVCodec	ff_evrc_decoder

Detailed Description

Enhanced Variable Rate Codec, Service Option 3 decoder.

Author: Paul B Mahol

Definition in file evrcdec.c.

Macro Definition Documentation

#define MIN_LSP_SEP (0.05 / (2.0 * M_PI))

Definition at line 36 of file evrcdec.c.

Referenced by decode_lspf().

#define MIN_DELAY 20

Definition at line 37 of file evrcdec.c.

Referenced by evrc_decode_frame(), frame_erasure(), and postfilter().

#define MAX_DELAY 120

Definition at line 38 of file evrcdec.c.

Referenced by evrc_decode_frame(), and postfilter().

#define NB_SUBFRAMES 3

Definition at line 39 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

#define SUBFRAME_SIZE 54

Definition at line 40 of file evrcdec.c.

Referenced by decode_frame(), decoder_init(), evrc_decode_frame(), ff_g729_postfilter(), frame_erasure(), g729d_get_new_exc(), long_term_filter(), and postfilter().

#define FILTER_ORDER 10

Definition at line 41 of file evrcdec.c.

Referenced by bandwidth_expansion(), decode_lspf(), decode_predictor_coeffs(), evrc_decode_frame(), evrc_decode_init(), frame_erasure(), interpolate_lsp(), postfilter(), residual_filter(), and synthesis_filter().

#define ACB_SIZE 128

Definition at line 42 of file evrcdec.c.

Referenced by evrc_decode_frame(), evrc_decode_init(), frame_erasure(), and postfilter().

Enumeration Type Documentation

enum evrc_packet_rate

Enumerator:

RATE_ERRS
SILENCE
RATE_QUANT
RATE_QUARTER
RATE_HALF
RATE_FULL

Definition at line 44 of file evrcdec.c.

Function Documentation

static void unpack_frame ( EVRCContext * e )

static

Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT.

Parameters

e	the context

TIA/IS-127 Table 4.21-1

Definition at line 103 of file evrcdec.c.

Referenced by evrc_decode_frame().

static evrc_packet_rate buf_size2bitrate ( const int buf_size )

static

Definition at line 160 of file evrcdec.c.

Referenced by determine_bitrate().

static evrc_packet_rate determine_bitrate	(	AVCodecContext *	avctx,
		int *	buf_size,
		const uint8_t **	buf
	)

static

Determine the bitrate from the frame size and/or the first byte of the frame.

Parameters

avctx	the AV codec context
buf_size	length of the buffer
buf	the bufffer

Returns: the bitrate on success, RATE_ERRS if the bitrate cannot be satisfactorily determined

Definition at line 183 of file evrcdec.c.

Referenced by evrc_decode_frame().

static void warn_insufficient_frame_quality	(	AVCodecContext *	avctx,
		const char *	message
	)

static

Definition at line 214 of file evrcdec.c.

Referenced by evrc_decode_frame().

static av_cold int evrc_decode_init ( AVCodecContext * avctx )

static

Initialize the speech codec according to the specification.

TIA/IS-127 5.2

Definition at line 226 of file evrcdec.c.

static int decode_lspf ( EVRCContext * e )

static

Decode the 10 vector quantized line spectral pair frequencies from the LSP transmission codes of any bitrate and check for badly received packets.

Parameters

e	the context

Returns: 0 on success, -1 if the packet is badly received

TIA/IS-127 5.2.1, 5.7.1

Definition at line 277 of file evrcdec.c.

Referenced by evrc_decode_frame().

static void interpolate_lsp	(	float *	ilsp,
		const float *	lsp,
		const float *	prev,
		int	index
	)

static

Definition at line 310 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

static void interpolate_delay	(	float *	dst,
		float	current,
		float	prev,
		int	index
	)

static

Definition at line 324 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

static void decode_predictor_coeffs	(	const float *	ilspf,
		float *	ilpc
	)

static

Definition at line 341 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

static void bl_intrp	(	EVRCContext *	e,
		float *	ex,
		float	delay
	)

static

Definition at line 371 of file evrcdec.c.

Referenced by acb_excitation().

static void acb_excitation	(	EVRCContext *	e,
		float *	excitation,
		float	gain,
		const float	delay[3],
		int	length
	)

static

Definition at line 399 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

static void decode_8_pulses_35bits	(	const uint16_t *	fixed_index,
		float *	cod
	)

static

Definition at line 426 of file evrcdec.c.

Referenced by fcb_excitation().

static void decode_3_pulses_10bits	(	uint16_t	fixed_index,
		float *	cod
	)

static

Definition at line 451 of file evrcdec.c.

Referenced by fcb_excitation().

static void fcb_excitation	(	EVRCContext *	e,
		const uint16_t *	codebook,
		float *	excitation,
		float	pitch_gain,
		int	pitch_lag,
		int	subframe_size
	)

static

Definition at line 471 of file evrcdec.c.

Referenced by evrc_decode_frame().

static void synthesis_filter	(	const float *	in,
		const float *	filter_coeffs,
		float *	memory,
		int	buffer_length,
		float *	samples
	)

static

Synthesis of the decoder output signal.

param[in] in input signal param[in] filter_coeffs LPC coefficients param[in/out] memory synthesis filter memory param buffer_length amount of data to process param[out] samples output samples

TIA/IS-127 5.2.3.15, 5.7.3.4

Definition at line 499 of file evrcdec.c.

Referenced by evrc_decode_frame(), frame_erasure(), and postfilter().

static void bandwidth_expansion	(	float *	coeff,
		const float *	inbuf,
		float	gamma
	)

static

Definition at line 515 of file evrcdec.c.

Referenced by evrc_decode_frame(), and postfilter().

static void residual_filter	(	float *	output,
		const float *	input,
		const float *	coef,
		float *	memory,
		int	length
	)

static

Definition at line 526 of file evrcdec.c.

Referenced by postfilter().

static void postfilter	(	EVRCContext *	e,
		float *	in,
		const float *	coeff,
		float *	out,
		int	idx,
		const struct PfCoeff *	pfc,
		int	length
	)

static

Definition at line 566 of file evrcdec.c.

Referenced by evrc_decode_frame(), and frame_erasure().

static void frame_erasure	(	EVRCContext *	e,
		float *	samples
	)

static

Definition at line 647 of file evrcdec.c.

Referenced by decode_frame(), and evrc_decode_frame().

static int evrc_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	got_frame_ptr,
		AVPacket *	avpkt
	)

static

Definition at line 737 of file evrcdec.c.

Variable Documentation

struct PfCoeff postfilter_coeffs[5]

static

Initial value:

= {
    { 0.0 , 0.0 , 0.0 , 0.0  },
    { 0.0 , 0.0 , 0.57, 0.57 },
    { 0.0 , 0.0 , 0.0 , 0.0  },
    { 0.35, 0.50, 0.50, 0.75 },
    { 0.20, 0.50, 0.57, 0.75 },
}

Referenced by evrc_decode_frame(), and frame_erasure().

AVCodec ff_evrc_decoder

Initial value:

= {
    .name           = "evrc",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_EVRC,
    .init           = evrc_decode_init,
    .decode         = evrc_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .priv_data_size = sizeof(EVRCContext),
    .long_name      = NULL_IF_CONFIG_SMALL("EVRC (Enhanced Variable Rate Codec)"),
}

Definition at line 908 of file evrcdec.c.

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation