asrc_sinc.c File Reference

#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "libavutil/tx.h"
#include "audio.h"
#include "avfilter.h"
#include "filters.h"
#include "internal.h"

Go to the source code of this file.

Data Structures
struct	SincContext

Macros
#define	SQR(a)   ((a) * (a))
#define	AF   AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
#define	OFFSET(x)   offsetof(SincContext, x)

Functions
static int	activate (AVFilterContext *ctx)
static int	query_formats (AVFilterContext *ctx)
static float	bessel_I_0 (float x)
static float *	make_lpf (int num_taps, float Fc, float beta, float rho, float scale, int dc_norm)
static float	kaiser_beta (float att, float tr_bw)
static void	kaiser_params (float att, float Fc, float tr_bw, float *beta, int *num_taps)
static float *	lpf (float Fn, float Fc, float tbw, int *num_taps, float att, float *beta, int round)
static void	invert (float *h, int n)
static float	safe_log (float x)
static int	fir_to_phase (SincContext *s, float **h, int *len, int *post_len, float phase)
static int	config_output (AVFilterLink *outlink)
static av_cold void	uninit (AVFilterContext *ctx)
	AVFILTER_DEFINE_CLASS (sinc)

Variables
static const AVFilterPad	sinc_outputs []
static const AVOption	sinc_options []
const AVFilter	ff_asrc_sinc

Macro Definition Documentation

SQR

#define SQR

(

a

)

((a) * (a))

Definition at line 206 of file asrc_sinc.c.

AF

#define AF   AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

Definition at line 414 of file asrc_sinc.c.

OFFSET

#define OFFSET

(

x

)

offsetof(SincContext, x)

Definition at line 415 of file asrc_sinc.c.

Function Documentation

activate()

static int activate ( AVFilterContext *  ctx )

static

Definition at line 48 of file asrc_sinc.c.

query_formats()

static int query_formats ( AVFilterContext *  ctx )

static

Definition at line 76 of file asrc_sinc.c.

bessel_I_0()

static float bessel_I_0 ( float  x )

static

Definition at line 94 of file asrc_sinc.c.

Referenced by make_lpf().

make_lpf()

static float* make_lpf ( int  num_taps, float  Fc, float  beta, float  rho, float  scale, int  dc_norm  )

static

Definition at line 109 of file asrc_sinc.c.

Referenced by lpf().

kaiser_beta()

static float kaiser_beta ( float  att, float  tr_bw  )

static

Definition at line 137 of file asrc_sinc.c.

Referenced by build_filter(), kaiser_params(), and resample_init().

kaiser_params()

static void kaiser_params ( float  att, float  Fc, float  tr_bw, float *  beta, int *  num_taps  )

static

Definition at line 167 of file asrc_sinc.c.

Referenced by lpf().

lpf()

static float* lpf ( float  Fn, float  Fc, float  tbw, int *  num_taps, float  att, float *  beta, int  round  )

static

Definition at line 175 of file asrc_sinc.c.

Referenced by config_output(), and fluxlr().

invert()

static void invert ( float *  h, int  n  )

static

Definition at line 198 of file asrc_sinc.c.

Referenced by bitplane_decoding(), config_output(), ff_h274_apply_film_grain(), ff_vfscanf(), and generate().

safe_log()

static float safe_log ( float  x )

static

Definition at line 208 of file asrc_sinc.c.

Referenced by fir_to_phase().

fir_to_phase()

static int fir_to_phase ( SincContext *  s, float **  h, int *  len, int *  post_len, float  phase  )

static

Definition at line 216 of file asrc_sinc.c.

Referenced by config_output().

config_output()

static int config_output ( AVFilterLink *  outlink )

static

Definition at line 337 of file asrc_sinc.c.

uninit()

static av_cold void uninit ( AVFilterContext *  ctx )

static

Definition at line 397 of file asrc_sinc.c.

AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS

(

sinc

)

Variable Documentation

sinc_outputs

const AVFilterPad sinc_outputs[]

static

Initial value:

= {
    {
        .name          = "default",
        .type          = AVMEDIA_TYPE_AUDIO,
        .config_props  = config_output,
    },
}

Definition at line 406 of file asrc_sinc.c.

sinc_options

const AVOption sinc_options[]

static

Initial value:

= {
    { "sample_rate", "set sample rate",                               OFFSET(sample_rate), AV_OPT_TYPE_INT,   {.i64=44100},  1, INT_MAX, AF },
    { "r",           "set sample rate",                               OFFSET(sample_rate), AV_OPT_TYPE_INT,   {.i64=44100},  1, INT_MAX, AF },
    { "nb_samples",  "set the number of samples per requested frame", OFFSET(nb_samples),  AV_OPT_TYPE_INT,   {.i64=1024},   1, INT_MAX, AF },
    { "n",           "set the number of samples per requested frame", OFFSET(nb_samples),  AV_OPT_TYPE_INT,   {.i64=1024},   1, INT_MAX, AF },
    { "hp",          "set high-pass filter frequency",                OFFSET(Fc0),         AV_OPT_TYPE_FLOAT, {.dbl=0},      0, INT_MAX, AF },
    { "lp",          "set low-pass filter frequency",                 OFFSET(Fc1),         AV_OPT_TYPE_FLOAT, {.dbl=0},      0, INT_MAX, AF },
    { "phase",       "set filter phase response",                     OFFSET(phase),       AV_OPT_TYPE_FLOAT, {.dbl=50},     0,     100, AF },
    { "beta",        "set kaiser window beta",                        OFFSET(beta),        AV_OPT_TYPE_FLOAT, {.dbl=-1},    -1,     256, AF },
    { "att",         "set stop-band attenuation",                     OFFSET(att),         AV_OPT_TYPE_FLOAT, {.dbl=120},   40,     180, AF },
    { "round",       "enable rounding",                               OFFSET(round),       AV_OPT_TYPE_BOOL,  {.i64=0},      0,       1, AF },
    { "hptaps",      "set number of taps for high-pass filter",       OFFSET(num_taps[0]), AV_OPT_TYPE_INT,   {.i64=0},      0,   32768, AF },
    { "lptaps",      "set number of taps for low-pass filter",        OFFSET(num_taps[1]), AV_OPT_TYPE_INT,   {.i64=0},      0,   32768, AF },
    { NULL }
}

Definition at line 417 of file asrc_sinc.c.

ff_asrc_sinc

const AVFilter ff_asrc_sinc

Initial value:

= {
    .name          = "sinc",
    .description   = NULL_IF_CONFIG_SMALL("Generate a sinc kaiser-windowed low-pass, high-pass, band-pass, or band-reject FIR coefficients."),
    .priv_size     = sizeof(SincContext),
    .priv_class    = &sinc_class,
    .uninit        = uninit,
    .activate      = activate,
    .inputs        = NULL,
    FILTER_OUTPUTS(sinc_outputs),
    FILTER_QUERY_FUNC(query_formats),
}

Definition at line 435 of file asrc_sinc.c.