mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-12 19:18:44 +02:00
444 lines
12 KiB
C
444 lines
12 KiB
C
/*
|
|
* Copyright (c) 2017 Paul B Mahol
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* Filter for reading closed captioning data (EIA-608).
|
|
* See also https://en.wikipedia.org/wiki/EIA-608
|
|
*/
|
|
|
|
#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"
|
|
|
|
#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
|
|
|
|
typedef struct LineItem {
|
|
int input;
|
|
int output;
|
|
|
|
float unfiltered;
|
|
float filtered;
|
|
float average;
|
|
float deviation;
|
|
} LineItem;
|
|
|
|
typedef struct CodeItem {
|
|
uint8_t bit;
|
|
int size;
|
|
} CodeItem;
|
|
|
|
typedef struct ReadEIA608Context {
|
|
const AVClass *class;
|
|
int start, end;
|
|
int nb_found;
|
|
int white;
|
|
int black;
|
|
float spw;
|
|
int chp;
|
|
int lp;
|
|
|
|
uint64_t histogram[256];
|
|
|
|
CodeItem *code;
|
|
LineItem *line;
|
|
} ReadEIA608Context;
|
|
|
|
#define OFFSET(x) offsetof(ReadEIA608Context, x)
|
|
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
|
|
|
|
static const AVOption readeia608_options[] = {
|
|
{ "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 }
|
|
};
|
|
|
|
AVFILTER_DEFINE_CLASS(readeia608);
|
|
|
|
static int query_formats(AVFilterContext *ctx)
|
|
{
|
|
static const enum AVPixelFormat pixel_fmts[] = {
|
|
AV_PIX_FMT_GRAY8,
|
|
AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
|
|
AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
|
|
AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
|
|
AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
|
|
AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
|
|
AV_PIX_FMT_YUVJ411P,
|
|
AV_PIX_FMT_NONE
|
|
};
|
|
AVFilterFormats *formats = ff_make_format_list(pixel_fmts);
|
|
if (!formats)
|
|
return AVERROR(ENOMEM);
|
|
return ff_set_common_formats(ctx, formats);
|
|
}
|
|
|
|
static int config_input(AVFilterLink *inlink)
|
|
{
|
|
AVFilterContext *ctx = inlink->dst;
|
|
ReadEIA608Context *s = ctx->priv;
|
|
int size = inlink->w + LAG;
|
|
|
|
if (s->end >= inlink->h) {
|
|
av_log(ctx, AV_LOG_WARNING, "Last line to scan too large, clipping.\n");
|
|
s->end = inlink->h - 1;
|
|
}
|
|
|
|
if (s->start > s->end) {
|
|
av_log(ctx, AV_LOG_ERROR, "Invalid range.\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
s->line = av_calloc(size, sizeof(*s->line));
|
|
s->code = av_calloc(size, sizeof(*s->code));
|
|
if (!s->line || !s->code)
|
|
return AVERROR(ENOMEM);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void build_histogram(ReadEIA608Context *s, const LineItem *line, int len)
|
|
{
|
|
memset(s->histogram, 0, sizeof(s->histogram));
|
|
|
|
for (int i = LAG; i < len + LAG; i++)
|
|
s->histogram[line[i].input]++;
|
|
}
|
|
|
|
static void find_black_and_white(ReadEIA608Context *s)
|
|
{
|
|
int start = 0, end = 0, middle;
|
|
int black = 0, white = 0;
|
|
int cnt;
|
|
|
|
for (int i = 0; i < 256; i++) {
|
|
if (s->histogram[i]) {
|
|
start = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
for (int i = 255; i >= 0; i--) {
|
|
if (s->histogram[i]) {
|
|
end = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
middle = start + (end - start) / 2;
|
|
|
|
cnt = 0;
|
|
for (int i = start; i <= middle; i++) {
|
|
if (s->histogram[i] > cnt) {
|
|
cnt = s->histogram[i];
|
|
black = i;
|
|
}
|
|
}
|
|
|
|
cnt = 0;
|
|
for (int i = end; i >= middle; i--) {
|
|
if (s->histogram[i] > cnt) {
|
|
cnt = s->histogram[i];
|
|
white = i;
|
|
}
|
|
}
|
|
|
|
s->black = black;
|
|
s->white = white;
|
|
}
|
|
|
|
static float meanf(const LineItem *line, int len)
|
|
{
|
|
float sum = 0.0, mean = 0.0;
|
|
|
|
for (int i = 0; i < len; i++)
|
|
sum += line[i].filtered;
|
|
|
|
mean = sum / len;
|
|
|
|
return mean;
|
|
}
|
|
|
|
static float stddevf(const LineItem *line, int len)
|
|
{
|
|
float m = meanf(line, len);
|
|
float standard_deviation = 0.f;
|
|
|
|
for (int i = 0; i < len; i++)
|
|
standard_deviation += (line[i].filtered - m) * (line[i].filtered - m);
|
|
|
|
return sqrtf(standard_deviation / (len - 1));
|
|
}
|
|
|
|
static void thresholding(ReadEIA608Context *s, LineItem *line,
|
|
int lag, float threshold, float influence, int len)
|
|
{
|
|
for (int i = lag; i < len + lag; i++) {
|
|
line[i].unfiltered = line[i].input / 255.f;
|
|
line[i].filtered = line[i].unfiltered;
|
|
}
|
|
|
|
for (int i = 0; i < lag; i++) {
|
|
line[i].unfiltered = meanf(line, len * s->spw);
|
|
line[i].filtered = line[i].unfiltered;
|
|
}
|
|
|
|
line[lag - 1].average = meanf(line, lag);
|
|
line[lag - 1].deviation = stddevf(line, lag);
|
|
|
|
for (int i = lag; i < len + lag; i++) {
|
|
if (fabsf(line[i].unfiltered - line[i-1].average) > threshold * line[i-1].deviation) {
|
|
if (line[i].unfiltered > line[i-1].average) {
|
|
line[i].output = 255;
|
|
} else {
|
|
line[i].output = 0;
|
|
}
|
|
|
|
line[i].filtered = influence * line[i].unfiltered + (1.f - influence) * line[i-1].filtered;
|
|
} else {
|
|
int distance_from_black, distance_from_white;
|
|
|
|
distance_from_black = FFABS(line[i].input - s->black);
|
|
distance_from_white = FFABS(line[i].input - s->white);
|
|
|
|
line[i].output = distance_from_black <= distance_from_white ? 0 : 255;
|
|
}
|
|
|
|
line[i].average = meanf(line + i - lag, lag);
|
|
line[i].deviation = stddevf(line + i - lag, lag);
|
|
}
|
|
}
|
|
|
|
static int periods(const LineItem *line, CodeItem *code, int len)
|
|
{
|
|
int hold = line[LAG].output, cnt = 0;
|
|
int last = LAG;
|
|
|
|
memset(code, 0, len * sizeof(*code));
|
|
|
|
for (int i = LAG + 1; i < len + LAG; i++) {
|
|
if (line[i].output != hold) {
|
|
code[cnt].size = i - last;
|
|
code[cnt].bit = hold;
|
|
hold = line[i].output;
|
|
last = i;
|
|
cnt++;
|
|
}
|
|
}
|
|
|
|
code[cnt].size = LAG + len - last;
|
|
code[cnt].bit = hold;
|
|
|
|
return cnt + 1;
|
|
}
|
|
|
|
static void dump_code(AVFilterContext *ctx, int len, int item)
|
|
{
|
|
ReadEIA608Context *s = ctx->priv;
|
|
|
|
av_log(ctx, AV_LOG_DEBUG, "%d:", item);
|
|
for (int i = 0; i < len; i++) {
|
|
av_log(ctx, AV_LOG_DEBUG, " %03d", s->code[i].size);
|
|
}
|
|
av_log(ctx, AV_LOG_DEBUG, "\n");
|
|
}
|
|
|
|
static void extract_line(AVFilterContext *ctx, AVFrame *in, int w, int nb_line)
|
|
{
|
|
ReadEIA608Context *s = ctx->priv;
|
|
LineItem *line = s->line;
|
|
int i, j, ch, len;
|
|
const uint8_t *src;
|
|
uint8_t byte[2] = { 0 };
|
|
uint8_t codes[19] = { 0 };
|
|
float bit_size = 0.f;
|
|
int parity;
|
|
|
|
memset(line, 0, (w + LAG) * sizeof(*line));
|
|
|
|
src = &in->data[0][nb_line * in->linesize[0]];
|
|
if (s->lp) {
|
|
for (i = 0; i < w; i++) {
|
|
int a = FFMAX(i - 3, 0);
|
|
int b = FFMAX(i - 2, 0);
|
|
int c = FFMAX(i - 1, 0);
|
|
int d = FFMIN(i + 3, w-1);
|
|
int e = FFMIN(i + 2, w-1);
|
|
int f = FFMIN(i + 1, w-1);
|
|
|
|
line[LAG + i].input = (src[a] + src[b] + src[c] + src[i] + src[d] + src[e] + src[f] + 6) / 7;
|
|
}
|
|
} else {
|
|
for (i = 0; i < w; i++) {
|
|
line[LAG + i].input = src[i];
|
|
}
|
|
}
|
|
|
|
build_histogram(s, line, w);
|
|
find_black_and_white(s);
|
|
if (s->white - s->black < 5)
|
|
return;
|
|
|
|
thresholding(s, line, LAG, 1, 0, w);
|
|
len = periods(line, s->code, w);
|
|
dump_code(ctx, len, nb_line);
|
|
if (len < 15 ||
|
|
s->code[14].bit != 0 ||
|
|
w / (float)s->code[14].size < SYNC_BITSIZE_MIN ||
|
|
w / (float)s->code[14].size > SYNC_BITSIZE_MAX) {
|
|
return;
|
|
}
|
|
|
|
for (i = 14; i < len; i++) {
|
|
bit_size += s->code[i].size;
|
|
}
|
|
|
|
bit_size /= 19.f;
|
|
for (i = 1; i < 14; i++) {
|
|
if (s->code[i].size / bit_size > CLOCK_BITSIZE_MAX ||
|
|
s->code[i].size / bit_size < CLOCK_BITSIZE_MIN) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (s->code[15].size / bit_size < 0.45f) {
|
|
return;
|
|
}
|
|
|
|
for (j = 0, i = 14; i < len; i++) {
|
|
int run, bit;
|
|
|
|
run = lrintf(s->code[i].size / bit_size);
|
|
bit = s->code[i].bit;
|
|
|
|
for (int k = 0; j < 19 && k < run; k++) {
|
|
codes[j++] = bit;
|
|
}
|
|
|
|
if (j >= 19)
|
|
break;
|
|
}
|
|
|
|
for (ch = 0; ch < 2; ch++) {
|
|
for (parity = 0, i = 0; i < 8; i++) {
|
|
int b = codes[3 + ch * 8 + i];
|
|
|
|
if (b == 255) {
|
|
parity++;
|
|
b = 1;
|
|
} else {
|
|
b = 0;
|
|
}
|
|
byte[ch] |= b << i;
|
|
}
|
|
|
|
if (s->chp) {
|
|
if (!(parity & 1)) {
|
|
byte[ch] = 0x7F;
|
|
}
|
|
}
|
|
}
|
|
|
|
{
|
|
uint8_t key[128], value[128];
|
|
|
|
//snprintf(key, sizeof(key), "lavfi.readeia608.%d.bits", s->nb_found);
|
|
//snprintf(value, sizeof(value), "0b%d%d%d%d%d%d%d%d 0b%d%d%d%d%d%d%d%d", codes[3]==255,codes[4]==255,codes[5]==255,codes[6]==255,codes[7]==255,codes[8]==255,codes[9]==255,codes[10]==255,codes[11]==255,codes[12]==255,codes[13]==255,codes[14]==255,codes[15]==255,codes[16]==255,codes[17]==255,codes[18]==255);
|
|
//av_dict_set(&in->metadata, key, value, 0);
|
|
|
|
snprintf(key, sizeof(key), "lavfi.readeia608.%d.cc", s->nb_found);
|
|
snprintf(value, sizeof(value), "0x%02X%02X", byte[0], byte[1]);
|
|
av_dict_set(&in->metadata, key, value, 0);
|
|
|
|
snprintf(key, sizeof(key), "lavfi.readeia608.%d.line", s->nb_found);
|
|
snprintf(value, sizeof(value), "%d", nb_line);
|
|
av_dict_set(&in->metadata, key, value, 0);
|
|
}
|
|
|
|
s->nb_found++;
|
|
}
|
|
|
|
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
|
|
{
|
|
AVFilterContext *ctx = inlink->dst;
|
|
AVFilterLink *outlink = ctx->outputs[0];
|
|
ReadEIA608Context *s = ctx->priv;
|
|
int i;
|
|
|
|
s->nb_found = 0;
|
|
for (i = s->start; i <= s->end; i++)
|
|
extract_line(ctx, in, inlink->w, i);
|
|
|
|
return ff_filter_frame(outlink, in);
|
|
}
|
|
|
|
static av_cold void uninit(AVFilterContext *ctx)
|
|
{
|
|
ReadEIA608Context *s = ctx->priv;
|
|
|
|
av_freep(&s->code);
|
|
av_freep(&s->line);
|
|
}
|
|
|
|
static const AVFilterPad readeia608_inputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.filter_frame = filter_frame,
|
|
.config_props = config_input,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static const AVFilterPad readeia608_outputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
AVFilter ff_vf_readeia608 = {
|
|
.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,
|
|
};
|