libavfilter/avf_showspectrum.c File Reference

audio to spectrum (video) transmedia filter, based on ffplay rdft showmode (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini). More...

#include <math.h>
#include "libavcodec/avfft.h"
#include "libavutil/audioconvert.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "internal.h"

Go to the source code of this file.

Data Structures
struct	ShowSpectrumContext
Defines
#define	OFFSET(x)   offsetof(ShowSpectrumContext, x)
#define	FLAGS   AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define	RE(ch)   data[ch][2*y + 0]
#define	IM(ch)   data[ch][2*y + 1]
#define	MAGNITUDE(re, im)   sqrt((re)*(re) + (im)*(im))
Functions
	AVFILTER_DEFINE_CLASS (showspectrum)
static av_cold int	init (AVFilterContext *ctx, const char *args)
static av_cold void	uninit (AVFilterContext *ctx)
static int	query_formats (AVFilterContext *ctx)
static int	config_output (AVFilterLink *outlink)
static void	push_frame (AVFilterLink *outlink)
static int	request_frame (AVFilterLink *outlink)
static int	plot_spectrum_column (AVFilterLink *inlink, AVFilterBufferRef *insamples, int nb_samples)
static int	filter_samples (AVFilterLink *inlink, AVFilterBufferRef *insamples)
Variables
static const AVOption	showspectrum_options []
AVFilter	avfilter_avf_showspectrum

---

Detailed Description

audio to spectrum (video) transmedia filter, based on ffplay rdft showmode (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini).

Definition in file avf_showspectrum.c.

---

Define Documentation

#define FLAGS   AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

Definition at line 50 of file avf_showspectrum.c.

#define IM

(

ch

)

data[ch][2*y + 1]

Referenced by plot_spectrum_column().

#define MAGNITUDE	(	re,
		im		)	sqrt((re)*(re) + (im)*(im))

Referenced by plot_spectrum_column().

#define OFFSET

(

x

)

offsetof(ShowSpectrumContext, x)

Definition at line 49 of file avf_showspectrum.c.

#define RE

(

ch

)

data[ch][2*y + 0]

Referenced by plot_spectrum_column().

---

Function Documentation

AVFILTER_DEFINE_CLASS

(

showspectrum

)

static int config_output

(

AVFilterLink *

outlink

)

[static]

Definition at line 118 of file avf_showspectrum.c.

static int filter_samples	(	AVFilterLink *	inlink,
		AVFilterBufferRef *	insamples
	)			[static]

Definition at line 271 of file avf_showspectrum.c.

static av_cold int init	(	AVFilterContext *	ctx,
		const char *	args
	)			[static]

Definition at line 60 of file avf_showspectrum.c.

static int plot_spectrum_column	(	AVFilterLink *	inlink,
		AVFilterBufferRef *	insamples,
		int	nb_samples
	)			[static]

Definition at line 206 of file avf_showspectrum.c.

Referenced by filter_samples().

static void push_frame

(

AVFilterLink *

outlink

)

[inline, static]

Definition at line 175 of file avf_showspectrum.c.

static int query_formats

(

AVFilterContext *

ctx

)

[static]

Definition at line 84 of file avf_showspectrum.c.

static int request_frame

(

AVFilterLink *

outlink

)

[static]

Definition at line 190 of file avf_showspectrum.c.

static av_cold void uninit

(

AVFilterContext *

ctx

)

[static]

Definition at line 74 of file avf_showspectrum.c.

---

Variable Documentation

AVFilter avfilter_avf_showspectrum

Initial value:

 {
    .name           = "showspectrum",
    .description    = NULL_IF_CONFIG_SMALL("Convert input audio to a spectrum video output."),
    .init           = init,
    .uninit         = uninit,
    .query_formats  = query_formats,
    .priv_size      = sizeof(ShowSpectrumContext),

    .inputs  = (const AVFilterPad[]) {
        {
            .name           = "default",
            .type           = AVMEDIA_TYPE_AUDIO,
            .filter_samples = filter_samples,
            .min_perms      = AV_PERM_READ,
        },
        { .name = NULL }
    },

    .outputs = (const AVFilterPad[]) {
        {
            .name           = "default",
            .type           = AVMEDIA_TYPE_VIDEO,
            .config_props   = config_output,
            .request_frame  = request_frame,
        },
        { .name = NULL }
    },

    .priv_class = &showspectrum_class,
}

Definition at line 288 of file avf_showspectrum.c.

const AVOption showspectrum_options[] [static]

Initial value:

 {
    { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, FLAGS },
    { "s",    "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, FLAGS },
    { NULL },
}

Definition at line 52 of file avf_showspectrum.c.