vf_readeia608.c File Reference

Filter for reading closed captioning data (EIA-608). More...

#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	ReadEIA608Context

Macros
#define	FALL   0
#define	RISE   1
#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	extract_line (AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *in, int line)
static int	filter_frame (AVFilterLink *inlink, AVFrame *in)

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

#define FALL   0

Definition at line 39 of file vf_readeia608.c.

Referenced by extract_line().

#define RISE   1

Definition at line 40 of file vf_readeia608.c.

Referenced by extract_line().

#define OFFSET

(

x

)

offsetof(ReadEIA608Context, x)

Definition at line 56 of file vf_readeia608.c.

#define FLAGS   AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

Definition at line 57 of file vf_readeia608.c.

Function Documentation

AVFILTER_DEFINE_CLASS

(

readeia608

)

static int query_formats ( AVFilterContext *  ctx )

static

Definition at line 76 of file vf_readeia608.c.

static int config_input ( AVFilterLink *  inlink )

static

Definition at line 94 of file vf_readeia608.c.

static void extract_line ( AVFilterContext *  ctx, AVFilterLink *  inlink, AVFrame *  in, int  line  )

static

Definition at line 121 of file vf_readeia608.c.

Referenced by filter_frame().

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

static

Definition at line 227 of file vf_readeia608.c.

Variable Documentation

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 },
    { "mac",      "set minimal acceptable amplitude change for sync codes detection", OFFSET(mac),   AV_OPT_TYPE_FLOAT, {.dbl=.2},  0.001,       1, FLAGS },
    { "spw",      "set ratio of width reserved for sync code detection",              OFFSET(spw),   AV_OPT_TYPE_FLOAT, {.dbl=.27},   0.1,     0.7, FLAGS },
    { "mhd",      "set max peaks height difference for sync code detection",          OFFSET(mhd),   AV_OPT_TYPE_FLOAT, {.dbl=.1},      0,     0.5, FLAGS },
    { "mpd",      "set max peaks period difference for sync code detection",          OFFSET(mpd),   AV_OPT_TYPE_FLOAT, {.dbl=.1},      0,     0.5, FLAGS },
    { "msd",      "set first two max start code bits differences",                    OFFSET(msd),   AV_OPT_TYPE_FLOAT, {.dbl=.02},     0,     0.5, FLAGS },
    { "bhd",      "set min ratio of bits height compared to 3rd start code bit",      OFFSET(bhd),   AV_OPT_TYPE_FLOAT, {.dbl=.75},  0.01,       1, FLAGS },
    { "th_w",     "set white color threshold",                                        OFFSET(wth),   AV_OPT_TYPE_FLOAT, {.dbl=.35},   0.1,       1, FLAGS },
    { "th_b",     "set black color threshold",                                        OFFSET(bth),   AV_OPT_TYPE_FLOAT, {.dbl=.15},     0,     0.5, FLAGS },
    { "chp",      "check and apply parity bit",                                       OFFSET(chp),   AV_OPT_TYPE_BOOL,  {.i64= 0},      0,       1, FLAGS },
    { NULL }
}

Definition at line 59 of file vf_readeia608.c.

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 241 of file vf_readeia608.c.

const AVFilterPad readeia608_outputs[]

static

Initial value:

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

Definition at line 251 of file vf_readeia608.c.

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,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
}

Definition at line 259 of file vf_readeia608.c.