libavcodec/g723_1.c File Reference

G.723.1 compatible decoder. More...

#include "libavutil/audioconvert.h"
#include "libavutil/lzo.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "acelp_vectors.h"
#include "celp_filters.h"
#include "celp_math.h"
#include "g723_1_data.h"

Go to the source code of this file.

Data Structures

struct g723_1_context

Defines

#define BITSTREAM_READER_LE

#define CNG_RANDOM_SEED   12345

#define normalize_bits_int16(num)   normalize_bits(num, 15)

#define normalize_bits_int32(num)   normalize_bits(num, 31)

#define MULL2(a, b)   MULL(a,b,15)

Bitexact implementation of 2ab scaled by 1/2^16.

#define iir_filter(fir_coef, iir_coef, src, dest, width)

Perform IIR filtering.

#define OFFSET(x)   offsetof(G723_1_Context, x)

#define AD   AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM

Typedefs

typedef struct g723_1_context G723_1_Context

Functions

static av_cold int g723_1_decode_init (AVCodecContext *avctx)

static int unpack_bitstream (G723_1_Context *p, const uint8_t *buf, int buf_size)

Unpack the frame into parameters.

static int16_t square_root (int val)

Bitexact implementation of sqrt(val/2).

static int normalize_bits (int num, int width)

Calculate the number of left-shifts required for normalizing the input.

static int scale_vector (int16_t *dst, const int16_t *vector, int length)

Scale vector contents based on the largest of their absolutes.

static void inverse_quant (int16_t *cur_lsp, int16_t *prev_lsp, uint8_t *lsp_index, int bad_frame)

Perform inverse quantization of LSP frequencies.

static void lsp2lpc (int16_t *lpc)

Convert LSP frequencies to LPC coefficients.

static void lsp_interpolate (int16_t *lpc, int16_t *cur_lsp, int16_t *prev_lsp)

Quantize LSP frequencies by interpolation and convert them to the corresponding LPC coefficients.

static void gen_dirac_train (int16_t *buf, int pitch_lag)

Generate a train of dirac functions with period as pitch lag.

static void gen_fcb_excitation (int16_t *vector, G723_1_Subframe *subfrm, enum Rate cur_rate, int pitch_lag, int index)

Generate fixed codebook excitation vector.

static void get_residual (int16_t *residual, int16_t *prev_excitation, int lag)

Get delayed contribution from the previous excitation vector.

static int dot_product (const int16_t *a, const int16_t *b, int length)

static void gen_acb_excitation (int16_t *vector, int16_t *prev_excitation, int pitch_lag, G723_1_Subframe *subfrm, enum Rate cur_rate)

Generate adaptive codebook excitation.

static int autocorr_max (const int16_t *buf, int offset, int *ccr_max, int pitch_lag, int length, int dir)

Estimate maximum auto-correlation around pitch lag.

static void comp_ppf_gains (int lag, PPFParam *ppf, enum Rate cur_rate, int tgt_eng, int ccr, int res_eng)

Calculate pitch postfilter optimal and scaling gains.

static void comp_ppf_coeff (G723_1_Context *p, int offset, int pitch_lag, PPFParam *ppf, enum Rate cur_rate)

Calculate pitch postfilter parameters.

static int comp_interp_index (G723_1_Context *p, int pitch_lag, int *exc_eng, int *scale)

Classify frames as voiced/unvoiced.

static void residual_interp (int16_t *buf, int16_t *out, int lag, int gain, int *rseed)

Peform residual interpolation based on frame classification.

static void gain_scale (G723_1_Context *p, int16_t *buf, int energy)

Adjust gain of postfiltered signal.

static void formant_postfilter (G723_1_Context *p, int16_t *lpc, int16_t *buf, int16_t *dst)

Perform formant filtering.

static int sid_gain_to_lsp_index (int gain)

static int cng_rand (int *state, int base)

static int estimate_sid_gain (G723_1_Context *p)

static void generate_noise (G723_1_Context *p)

static int g723_1_decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)

Variables

static const AVOption options []

static const AVClass g723_1dec_class

AVCodec ff_g723_1_decoder

Detailed Description

G.723.1 compatible decoder.

Definition in file g723_1.c.

Define Documentation

#define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM

Definition at line 1320 of file g723_1.c.

#define BITSTREAM_READER_LE

Definition at line 28 of file g723_1.c.

#define CNG_RANDOM_SEED 12345

Definition at line 40 of file g723_1.c.

Referenced by g723_1_decode_frame(), and g723_1_decode_init().

#define iir_filter	(	fir_coef,
		iir_coef,
		src,
		dest,
		width	)

Value:

{\
    int m, n;\
    int res_shift = 16 & ~-(width);\
    int in_shift  = 16 - res_shift;\
\
    for (m = 0; m < SUBFRAME_LEN; m++) {\
        int64_t filter = 0;\
        for (n = 1; n <= LPC_ORDER; n++) {\
            filter -= (fir_coef)[n - 1] * (src)[m - n] -\
                      (iir_coef)[n - 1] * ((dest)[m - n] >> in_shift);\
        }\
\
        (dest)[m] = av_clipl_int32(((src)[m] << 16) + (filter << 3) +\
                                   (1 << 15)) >> res_shift;\
    }\
}

Perform IIR filtering.

Parameters:

	fir_coef	FIR coefficients
	iir_coef	IIR coefficients
	src	source vector
	dest	destination vector
	width	width of the output, 16 bits(0) / 32 bits(1)

Definition at line 823 of file g723_1.c.

Referenced by formant_postfilter().

#define MULL2	(	a,
		b		)	MULL(a,b,15)

Bitexact implementation of 2ab scaled by 1/2^16.

Parameters:

	a	32 bit multiplicand
	b	16 bit multiplier

Definition at line 344 of file g723_1.c.

Referenced by lsp2lpc().

#define normalize_bits_int16 ( num ) normalize_bits(num, 15)

Definition at line 245 of file g723_1.c.

#define normalize_bits_int32 ( num ) normalize_bits(num, 31)

Definition at line 246 of file g723_1.c.

#define OFFSET ( x ) offsetof(G723_1_Context, x)

Definition at line 1319 of file g723_1.c.

Typedef Documentation

typedef struct g723_1_context G723_1_Context

Function Documentation

static int autocorr_max	(	const int16_t *	buf,
		int	offset,
		int *	ccr_max,
		int	pitch_lag,
		int	length,
		int	dir
	)			`[static]`

Estimate maximum auto-correlation around pitch lag.

Parameters:

	buf	buffer with offset applied
	offset	offset of the excitation vector
	ccr_max	pointer to the maximum auto-correlation
	pitch_lag	decoded pitch lag
	length	length of autocorrelation
	dir	forward lag(1) / backward lag(-1)

Definition at line 585 of file g723_1.c.

Referenced by comp_interp_index(), and comp_ppf_coeff().

static int cng_rand	(	int *	state,
		int	base
	)			`[inline, static]`

Definition at line 969 of file g723_1.c.

Referenced by generate_noise().

static int comp_interp_index	(	G723_1_Context *	p,
		int	pitch_lag,
		int *	exc_eng,
		int *	scale
	)			`[static]`

Classify frames as voiced/unvoiced.

Parameters:

	p	the context
	pitch_lag	decoded pitch_lag
	exc_eng	excitation energy estimation
	scale	scaling factor of exc_eng

Returns:: residual interpolation index if voiced, 0 otherwise

Definition at line 750 of file g723_1.c.

Referenced by g723_1_decode_frame().

static void comp_ppf_coeff	(	G723_1_Context *	p,
		int	offset,
		int	pitch_lag,
		PPFParam *	ppf,
		enum Rate	cur_rate
	)			`[static]`

Calculate pitch postfilter parameters.

Parameters:

	p	the context
	offset	offset of the excitation vector
	pitch_lag	decoded pitch lag
	ppf	pitch postfilter parameters
	cur_rate	current bitrate

Definition at line 666 of file g723_1.c.

Referenced by g723_1_decode_frame().

static void comp_ppf_gains	(	int	lag,
		PPFParam *	ppf,
		enum Rate	cur_rate,
		int	tgt_eng,
		int	ccr,
		int	res_eng
	)			`[static]`

Calculate pitch postfilter optimal and scaling gains.

Parameters:

	lag	pitch postfilter forward/backward lag
	ppf	pitch postfilter parameters
	cur_rate	current bitrate
	tgt_eng	target energy
	ccr	cross-correlation
	res_eng	residual energy

Definition at line 618 of file g723_1.c.

Referenced by comp_ppf_coeff().

static int dot_product	(	const int16_t *	a,
		const int16_t *	b,
		int	length
	)			`[static]`

Definition at line 539 of file g723_1.c.

Referenced by autocorr_max(), comp_interp_index(), comp_ppf_coeff(), and formant_postfilter().

static int estimate_sid_gain ( G723_1_Context * p ) [static]

Definition at line 975 of file g723_1.c.

Referenced by g723_1_decode_frame().

static void formant_postfilter	(	G723_1_Context *	p,
		int16_t *	lpc,
		int16_t *	buf,
		int16_t *	dst
	)			`[static]`

Perform formant filtering.

Parameters:

	p	the context
	lpc	quantized lpc coefficients
	buf	input buffer
	dst	output buffer

Definition at line 891 of file g723_1.c.

Referenced by g723_1_decode_frame().

static int g723_1_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	got_frame_ptr,
		AVPacket *	avpkt
	)			`[static]`

Definition at line 1154 of file g723_1.c.

static av_cold int g723_1_decode_init ( AVCodecContext * avctx ) [static]

Definition at line 86 of file g723_1.c.

static void gain_scale	(	G723_1_Context *	p,
		int16_t *	buf,
		int	energy
	)			`[static]`

Adjust gain of postfiltered signal.

Parameters:

	p	the context
	buf	postfiltered output vector
	energy	input energy coefficient

Definition at line 848 of file g723_1.c.

Referenced by formant_postfilter().

static void gen_acb_excitation	(	int16_t *	vector,
		int16_t *	prev_excitation,
		int	pitch_lag,
		G723_1_Subframe *	subfrm,
		enum Rate	cur_rate
	)			`[static]`

Generate adaptive codebook excitation.

Definition at line 548 of file g723_1.c.

Referenced by g723_1_decode_frame(), and generate_noise().

static void gen_dirac_train	(	int16_t *	buf,
		int	pitch_lag
	)			`[static]`

Generate a train of dirac functions with period as pitch lag.

Definition at line 445 of file g723_1.c.

Referenced by gen_fcb_excitation().

static void gen_fcb_excitation	(	int16_t *	vector,
		G723_1_Subframe *	subfrm,
		enum Rate	cur_rate,
		int	pitch_lag,
		int	index
	)			`[static]`

Generate fixed codebook excitation vector.

Parameters:

	vector	decoded excitation vector
	subfrm	current subframe
	cur_rate	current bitrate
	pitch_lag	closed loop pitch lag
	index	current subframe index

Definition at line 466 of file g723_1.c.

Referenced by g723_1_decode_frame().

static void generate_noise ( G723_1_Context * p ) [static]

Definition at line 1029 of file g723_1.c.

Referenced by g723_1_decode_frame().

static void get_residual	(	int16_t *	residual,
		int16_t *	prev_excitation,
		int	lag
	)			`[static]`

Get delayed contribution from the previous excitation vector.

Definition at line 526 of file g723_1.c.

Referenced by gen_acb_excitation().

static void inverse_quant	(	int16_t *	cur_lsp,
		int16_t *	prev_lsp,
		uint8_t *	lsp_index,
		int	bad_frame
	)			`[static]`

Perform inverse quantization of LSP frequencies.

Parameters:

	cur_lsp	the current LSP vector
	prev_lsp	the previous LSP vector
	lsp_index	VQ indices
	bad_frame	bad frame flag

Definition at line 276 of file g723_1.c.

Referenced by g723_1_decode_frame(), and g726_decode().

static void lsp2lpc ( int16_t * lpc ) [static]

Convert LSP frequencies to LPC coefficients.

Parameters:

lpc

buffer for LPC coefficients

Definition at line 352 of file g723_1.c.

Referenced by lsp_interpolate().

static void lsp_interpolate	(	int16_t *	lpc,
		int16_t *	cur_lsp,
		int16_t *	prev_lsp
	)			`[static]`

Quantize LSP frequencies by interpolation and convert them to the corresponding LPC coefficients.

Parameters:

	lpc	buffer for LPC coefficients
	cur_lsp	the current LSP vector
	prev_lsp	the previous LSP vector

Definition at line 422 of file g723_1.c.

Referenced by g723_1_decode_frame().

static int normalize_bits	(	int	num,
		int	width
	)			`[static]`

Calculate the number of left-shifts required for normalizing the input.

Parameters:

	num	input number
	width	width of the input, 15 or 31 bits

Definition at line 240 of file g723_1.c.

Referenced by comp_ppf_coeff(), and gain_scale().

static void residual_interp	(	int16_t *	buf,
		int16_t *	out,
		int	lag,
		int	gain,
		int *	rseed
	)			`[static]`

Peform residual interpolation based on frame classification.

Parameters:

	buf	decoded excitation vector
	out	output vector
	lag	decoded pitch lag
	gain	interpolated gain
	rseed	seed for random number generator

Definition at line 794 of file g723_1.c.

Referenced by g723_1_decode_frame().

static int scale_vector	(	int16_t *	dst,
		const int16_t *	vector,
		int	length
	)			`[static]`

Scale vector contents based on the largest of their absolutes.

Definition at line 251 of file g723_1.c.

Referenced by comp_interp_index(), and formant_postfilter().

static int sid_gain_to_lsp_index ( int gain ) [static]

Definition at line 959 of file g723_1.c.

Referenced by g723_1_decode_frame().

static int16_t square_root ( int val ) [static]

Bitexact implementation of sqrt(val/2).

Definition at line 229 of file g723_1.c.

Referenced by comp_ppf_gains(), gain_scale(), and generate_noise().

static int unpack_bitstream	(	G723_1_Context *	p,
		const uint8_t *	buf,
		int	buf_size
	)			`[static]`

Unpack the frame into parameters.

Parameters:

	p	the context
	buf	pointer to the input buffer
	buf_size	size of the input buffer

Definition at line 114 of file g723_1.c.

Variable Documentation

AVCodec ff_g723_1_decoder

Initial value:

 {
    .name           = "g723_1",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_G723_1,
    .priv_data_size = sizeof(G723_1_Context),
    .init           = g723_1_decode_init,
    .decode         = g723_1_decode_frame,
    .long_name      = NULL_IF_CONFIG_SMALL("G.723.1"),
    .capabilities   = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
    .priv_class     = &g723_1dec_class,
}

Definition at line 1336 of file g723_1.c.

const AVClass g723_1dec_class [static]

Initial value:

 {
    .class_name = "G.723.1 decoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
}

Definition at line 1329 of file g723_1.c.

const AVOption options[] [static]

Initial value:

 {
    { "postfilter", "postfilter on/off", OFFSET(postfilter), AV_OPT_TYPE_INT,
      { .i64 = 1 }, 0, 1, AD },
    { NULL }
}

Definition at line 1322 of file g723_1.c.


Data Structures
struct	g723_1_context
Defines
#define	BITSTREAM_READER_LE
#define	CNG_RANDOM_SEED 12345
#define	normalize_bits_int16(num) normalize_bits(num, 15)
#define	normalize_bits_int32(num) normalize_bits(num, 31)
#define	MULL2(a, b) MULL(a,b,15)
	Bitexact implementation of 2ab scaled by 1/2^16.
#define	iir_filter(fir_coef, iir_coef, src, dest, width)
	Perform IIR filtering.
#define	OFFSET(x) offsetof(G723_1_Context, x)
#define	AD AV_OPT_FLAG_AUDIO_PARAM \| AV_OPT_FLAG_DECODING_PARAM
Typedefs
typedef struct g723_1_context	G723_1_Context
Functions
static av_cold int	g723_1_decode_init (AVCodecContext *avctx)
static int	unpack_bitstream (G723_1_Context p, const uint8_t buf, int buf_size)
	Unpack the frame into parameters.
static int16_t	square_root (int val)
	Bitexact implementation of sqrt(val/2).
static int	normalize_bits (int num, int width)
	Calculate the number of left-shifts required for normalizing the input.
static int	scale_vector (int16_t dst, const int16_t vector, int length)
	Scale vector contents based on the largest of their absolutes.
static void	inverse_quant (int16_t cur_lsp, int16_t prev_lsp, uint8_t *lsp_index, int bad_frame)
	Perform inverse quantization of LSP frequencies.
static void	lsp2lpc (int16_t *lpc)
	Convert LSP frequencies to LPC coefficients.
static void	lsp_interpolate (int16_t lpc, int16_t cur_lsp, int16_t *prev_lsp)
	Quantize LSP frequencies by interpolation and convert them to the corresponding LPC coefficients.
static void	gen_dirac_train (int16_t *buf, int pitch_lag)
	Generate a train of dirac functions with period as pitch lag.
static void	gen_fcb_excitation (int16_t vector, G723_1_Subframe subfrm, enum Rate cur_rate, int pitch_lag, int index)
	Generate fixed codebook excitation vector.
static void	get_residual (int16_t residual, int16_t prev_excitation, int lag)
	Get delayed contribution from the previous excitation vector.
static int	dot_product (const int16_t a, const int16_t b, int length)
static void	gen_acb_excitation (int16_t vector, int16_t prev_excitation, int pitch_lag, G723_1_Subframe *subfrm, enum Rate cur_rate)
	Generate adaptive codebook excitation.
static int	autocorr_max (const int16_t buf, int offset, int ccr_max, int pitch_lag, int length, int dir)
	Estimate maximum auto-correlation around pitch lag.
static void	comp_ppf_gains (int lag, PPFParam *ppf, enum Rate cur_rate, int tgt_eng, int ccr, int res_eng)
	Calculate pitch postfilter optimal and scaling gains.
static void	comp_ppf_coeff (G723_1_Context p, int offset, int pitch_lag, PPFParam ppf, enum Rate cur_rate)
	Calculate pitch postfilter parameters.
static int	comp_interp_index (G723_1_Context p, int pitch_lag, int exc_eng, int *scale)
	Classify frames as voiced/unvoiced.
static void	residual_interp (int16_t buf, int16_t out, int lag, int gain, int *rseed)
	Peform residual interpolation based on frame classification.
static void	gain_scale (G723_1_Context p, int16_t buf, int energy)
	Adjust gain of postfiltered signal.
static void	formant_postfilter (G723_1_Context p, int16_t lpc, int16_t buf, int16_t dst)
	Perform formant filtering.
static int	sid_gain_to_lsp_index (int gain)
static int	cng_rand (int *state, int base)
static int	estimate_sid_gain (G723_1_Context *p)
static void	generate_noise (G723_1_Context *p)
static int	g723_1_decode_frame (AVCodecContext avctx, void data, int got_frame_ptr, AVPacket avpkt)
Variables
static const AVOption	options []
static const AVClass	g723_1dec_class
AVCodec	ff_g723_1_decoder