vf_readeia608.c File Reference

#include <string.h>
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/timestamp.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

Go to the source code of this file.

Data Structures
struct	LineItem
struct	CodeItem
struct	ReadEIA608Context

Macros
#define	LAG   25
#define	CLOCK_BITSIZE_MIN   0.2f
#define	CLOCK_BITSIZE_MAX   1.5f
#define	SYNC_BITSIZE_MIN   12.f
#define	SYNC_BITSIZE_MAX   15.f
#define	OFFSET(x)   offsetof(ReadEIA608Context, x)
#define	FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

Functions
	AVFILTER_DEFINE_CLASS (readeia608)
static int	query_formats (AVFilterContext *ctx)
static int	config_input (AVFilterLink *inlink)
static void	build_histogram (ReadEIA608Context *s, const LineItem *line, int len)
static void	find_black_and_white (ReadEIA608Context *s)
static float	meanf (const LineItem *line, int len)
static float	stddevf (const LineItem *line, int len)
static void	thresholding (ReadEIA608Context *s, LineItem *line, int lag, float threshold, float influence, int len)
static int	periods (const LineItem *line, CodeItem *code, int len)
static void	dump_code (AVFilterContext *ctx, int len, int item)
static void	extract_line (AVFilterContext *ctx, AVFrame *in, int w, int nb_line)
static int	filter_frame (AVFilterLink *inlink, AVFrame *in)
static av_cold void	uninit (AVFilterContext *ctx)

Variables
static const AVOption	readeia608_options []
static const AVFilterPad	readeia608_inputs []
static const AVFilterPad	readeia608_outputs []
AVFilter	ff_vf_readeia608

Detailed Description

Filter for reading closed captioning data (EIA-608). See also https://en.wikipedia.org/wiki/EIA-608

Definition in file vf_readeia608.c.

Macro Definition Documentation

LAG

#define LAG   25

Definition at line 39 of file vf_readeia608.c.

CLOCK_BITSIZE_MIN

#define CLOCK_BITSIZE_MIN   0.2f

Definition at line 40 of file vf_readeia608.c.

CLOCK_BITSIZE_MAX

#define CLOCK_BITSIZE_MAX   1.5f

Definition at line 41 of file vf_readeia608.c.

SYNC_BITSIZE_MIN

#define SYNC_BITSIZE_MIN   12.f

Definition at line 42 of file vf_readeia608.c.

SYNC_BITSIZE_MAX

#define SYNC_BITSIZE_MAX   15.f

Definition at line 43 of file vf_readeia608.c.

OFFSET

#define OFFSET

(

x

)

offsetof(ReadEIA608Context, x)

Definition at line 76 of file vf_readeia608.c.

FLAGS

#define FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

Definition at line 77 of file vf_readeia608.c.

Function Documentation

AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS

(

readeia608

)

query_formats()

static int query_formats ( AVFilterContext *  ctx )

static

Definition at line 90 of file vf_readeia608.c.

config_input()

static int config_input ( AVFilterLink *  inlink )

static

Definition at line 108 of file vf_readeia608.c.

build_histogram()

static void build_histogram ( ReadEIA608Context *  s, const LineItem *  line, int  len  )

static

Definition at line 132 of file vf_readeia608.c.

Referenced by extract_line().

find_black_and_white()

static void find_black_and_white ( ReadEIA608Context *  s )

static

Definition at line 140 of file vf_readeia608.c.

Referenced by extract_line().

meanf()

static float meanf ( const LineItem *  line, int  len  )

static

Definition at line 182 of file vf_readeia608.c.

Referenced by stddevf(), and thresholding().

stddevf()

static float stddevf ( const LineItem *  line, int  len  )

static

Definition at line 194 of file vf_readeia608.c.

Referenced by thresholding().

thresholding()

static void thresholding ( ReadEIA608Context *  s, LineItem *  line, int  lag, float  threshold, float  influence, int  len  )

static

Definition at line 205 of file vf_readeia608.c.

Referenced by extract_line().

periods()

static int periods ( const LineItem *  line, CodeItem *  code, int  len  )

static

Definition at line 244 of file vf_readeia608.c.

Referenced by extract_line().

dump_code()

static void dump_code ( AVFilterContext *  ctx, int  len, int  item  )

static

Definition at line 267 of file vf_readeia608.c.

Referenced by extract_line().

extract_line()

static void extract_line ( AVFilterContext *  ctx, AVFrame *  in, int  w, int  nb_line  )

static

Definition at line 278 of file vf_readeia608.c.

Referenced by filter_frame().

filter_frame()

static int filter_frame ( AVFilterLink *  inlink, AVFrame *  in  )

static

Definition at line 393 of file vf_readeia608.c.

uninit()

static av_cold void uninit ( AVFilterContext *  ctx )

static

Definition at line 407 of file vf_readeia608.c.

Variable Documentation

readeia608_options

const AVOption readeia608_options[]

static

Initial value:

= {
    { "scan_min", "set from which line to scan for codes",               OFFSET(start), AV_OPT_TYPE_INT,   {.i64=0},     0, INT_MAX, FLAGS },
    { "scan_max", "set to which line to scan for codes",                 OFFSET(end),   AV_OPT_TYPE_INT,   {.i64=29},    0, INT_MAX, FLAGS },
    { "spw",      "set ratio of width reserved for sync code detection", OFFSET(spw),   AV_OPT_TYPE_FLOAT, {.dbl=.27}, 0.1,     0.7, FLAGS },
    { "chp",      "check and apply parity bit",                          OFFSET(chp),   AV_OPT_TYPE_BOOL,  {.i64= 0},    0,       1, FLAGS },
    { "lp",       "lowpass line prior to processing",                    OFFSET(lp),    AV_OPT_TYPE_BOOL,  {.i64= 1},    0,       1, FLAGS },
    { NULL }
}

Definition at line 79 of file vf_readeia608.c.

readeia608_inputs

const AVFilterPad readeia608_inputs[]

static

Initial value:

= {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
        .config_props = config_input,
    },
    { NULL }
}

Definition at line 415 of file vf_readeia608.c.

readeia608_outputs

const AVFilterPad readeia608_outputs[]

static

Initial value:

= {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_VIDEO,
    },
    { NULL }
}

Definition at line 425 of file vf_readeia608.c.

ff_vf_readeia608

AVFilter ff_vf_readeia608

Initial value:

= {
    .name          = "readeia608",
    .description   = NULL_IF_CONFIG_SMALL("Read EIA-608 Closed Caption codes from input video and write them to frame metadata."),
    .priv_size     = sizeof(ReadEIA608Context),
    .priv_class    = &readeia608_class,
    .query_formats = query_formats,
    .inputs        = readeia608_inputs,
    .outputs       = readeia608_outputs,
    .uninit        = uninit,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
}

Definition at line 433 of file vf_readeia608.c.