Skip to content

F
ffmpeg.wasm-core
Commit 786a2daa authored by Paul B Mahol's avatar Paul B Mahol
Browse files
Options

avfilter/vf_readeia608: rewrite processing, make extracting more robust 

Lots of options are now obsolete.
parent dbb05176
Hide whitespace changes
Inline Side-by-side
Showing with 229 additions and 117 deletions
doc/filters.texi
View file @ 786a2daa
......@@ -15348,42 +15348,16 @@ Set the line to start scanning for EIA-608 data. Default is @code{0}.
@item scan_max
Set the line to end scanning for EIA-608 data. Default is @code{29}.
@item mac
Set minimal acceptable amplitude change for sync codes detection.
Default is @code{0.2}. Allowed range is @code{[0.001 - 1]}.
@item spw
Set the ratio of width reserved for sync code detection.
Default is @code{0.27}. Allowed range is @code{[0.01 - 0.7]}.
@item mhd
Set the max peaks height difference for sync code detection.
Default is @code{0.1}. Allowed range is @code{[0.0 - 0.5]}.
@item mpd
Set max peaks period difference for sync code detection.
Default is @code{0.1}. Allowed range is @code{[0.0 - 0.5]}.
@item msd
Set the first two max start code bits differences.
Default is @code{0.02}. Allowed range is @code{[0.0 - 0.5]}.
@item bhd
Set the minimum ratio of bits height compared to 3rd start code bit.
Default is @code{0.75}. Allowed range is @code{[0.01 - 1]}.
@item th_w
Set the white color threshold. Default is @code{0.35}. Allowed range is @code{[0.1 - 1]}.
@item th_b
Set the black color threshold. Default is @code{0.15}. Allowed range is @code{[0.0 - 0.5]}.
Default is @code{0.27}. Allowed range is @code{[0.1 - 0.7]}.
@item chp
Enable checking the parity bit. In the event of a parity error, the filter will output
@code{0x00} for that character. Default is false.
@item lp
Lowpass lines prior to further processing. Default is disabled.
Lowpass lines prior to further processing. Default is enabled.
@end table
@subsection Examples
......
libavfilter/vf_readeia608.c
View file @ 786a2daa
......@@ -36,41 +36,45 @@
#include "internal.h"
#include "video.h"
#define FALL 0
#define RISE 1
#define LAG 25
#define SYNC_MIN 12.f
#define SYNC_MAX 15.f
typedef struct CodeItem {
uint8_t bit;
int size;
} CodeItem;
typedef struct ReadEIA608Context {
const AVClass *class;
int start, end;
int min_range;
int max_peak_diff;
int max_period_diff;
int max_start_diff;
int nb_found;
int white;
int black;
float mpd, mhd, msd, mac, spw, bhd, wth, bth;
float spw;
int chp;
int lp;
uint64_t histogram[256];
uint8_t *temp;
uint8_t *signal;
CodeItem *code;
float *unfiltered;
float *filtered;
float *avg_filter;
float *std_filter;
} 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 },
{ "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 },
{ "lp", "lowpass line prior to processing", OFFSET(lp), AV_OPT_TYPE_BOOL, {.i64= 0}, 0, 1, FLAGS },
{ "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 }
};
......@@ -96,10 +100,9 @@ static int query_formats(AVFilterContext *ctx)
static int config_input(AVFilterLink *inlink)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
AVFilterContext *ctx = inlink->dst;
ReadEIA608Context *s = ctx->priv;
int depth = desc->comp[0].depth;
int size = inlink->w + LAG;
if (s->end >= inlink->h) {
av_log(ctx, AV_LOG_WARNING, "Last line to scan too large, clipping.\n");
......@@ -111,34 +114,177 @@ static int config_input(AVFilterLink *inlink)
return AVERROR(EINVAL);
}
s->min_range = s->mac * ((1 << depth) - 1);
s->max_peak_diff = s->mhd * ((1 << depth) - 1);
s->max_period_diff = s->mpd * ((1 << depth) - 1);
s->max_start_diff = s->msd * ((1 << depth) - 1);
s->white = s->wth * ((1 << depth) - 1);
s->black = s->bth * ((1 << depth) - 1);
s->temp = av_calloc(inlink->w, sizeof(*s->temp));
s->unfiltered = av_calloc(size, sizeof(*s->unfiltered));
s->filtered = av_calloc(size, sizeof(*s->filtered));
s->avg_filter = av_calloc(size, sizeof(*s->avg_filter));
s->std_filter = av_calloc(size, sizeof(*s->std_filter));
s->signal = av_calloc(size, sizeof(*s->signal));
s->code = av_calloc(size, sizeof(*s->code));
s->temp = av_calloc(size, sizeof(*s->temp));
if (!s->temp)
return AVERROR(ENOMEM);
return 0;
}
static void build_histogram(ReadEIA608Context *s, const uint8_t *src, int len)
{
memset(s->histogram, 0, sizeof(s->histogram));
for (int i = 0; i < len; i++)
s->histogram[src[i]]++;
}
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(float *data, int len)
{
float sum = 0.0, mean = 0.0;
for (int i = 0; i < len; i++)
sum += data[i];
mean = sum / len;
return mean;
}
static float stddevf(float *data, int len)
{
float m = meanf(data, len);
float standard_deviation = 0.f;
for (int i = 0; i < len; i++)
standard_deviation += (data[i] - m) * (data[i] - m);
return sqrtf(standard_deviation / (len - 1));
}
static void thresholding(ReadEIA608Context *s, const uint8_t *y, uint8_t *signal,
float *unfiltered, float *filtered, float *avg_filter, float *std_filter,
int lag, float threshold, float influence, int len)
{
for (int i = lag; i < len + lag; i++) {
unfiltered[i] = y[i - lag] / 255.f;
filtered[i] = unfiltered[i];
}
for (int i = 0; i < lag; i++) {
unfiltered[i] = meanf(unfiltered, len * s->spw);
filtered[i] = unfiltered[i];
}
memset(signal, 0, len);
avg_filter[lag - 1] = meanf(unfiltered, lag);
std_filter[lag - 1] = stddevf(unfiltered, lag);
for (int i = lag; i < len + lag; i++) {
if (fabsf(unfiltered[i] - avg_filter[i-1]) > threshold * std_filter[i-1]) {
if (unfiltered[i] > avg_filter[i-1]) {
signal[i - lag] = 255;
} else {
signal[i - lag] = 0;
}
filtered[i] = influence * unfiltered[i] + (1.f - influence) * filtered[i-1];
} else {
int distance_from_black, distance_from_white;
distance_from_black = FFABS(y[i - lag] - s->black);
distance_from_white = FFABS(y[i - lag] - s->white);
signal[i - lag] = distance_from_black <= distance_from_white ? 0 : 255;
}
avg_filter[i] = meanf(filtered + i - lag, lag);
std_filter[i] = stddevf(filtered + i - lag, lag);
}
}
static int periods(const uint8_t *signal, CodeItem *code, int len)
{
int hold = signal[0], cnt = 0;
int last = 0;
memset(code, 0, len * sizeof(*code));
for (int i = 1; i < len; i++) {
if (signal[i] != hold) {
code[cnt].size = i - last;
code[cnt].bit = hold;
hold = signal[i];
last = i;
cnt++;
}
}
code[cnt].size = 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, AVFilterLink *inlink, AVFrame *in, int line)
{
ReadEIA608Context *s = ctx->priv;
int max = 0, min = INT_MAX;
int i, ch, range = 0;
int i, j, ch, len;
const uint8_t *src;
uint16_t clock[8][2] = { { 0 } };
const int sync_width = s->spw * in->width;
int last = 0, peaks = 0, max_peak_diff = 0, dir = RISE;
const int width_per_bit = (in->width - sync_width) / 19;
uint8_t byte[2] = { 0 };
int s1, s2, s3, parity;
uint8_t codes[19] = { 0 };
float bit_size = 0.f;
int parity;
src = &in->data[0][line * in->linesize[0]];
if (s->lp) {
uint8_t *dst = s->temp;
int w = inlink->w - 1;
......@@ -157,78 +303,60 @@ static void extract_line(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *in
src = s->temp;
}
for (i = 0; i < sync_width; i++) {
max = FFMAX(max, src[i]);
min = FFMIN(min, src[i]);
}
range = max - min;
if (range < s->min_range)
build_histogram(s, src, inlink->w);
find_black_and_white(s);
if (s->white - s->black < 5)
return;
for (i = 0; i < sync_width; i++) {
int Y = src[i];
if (dir == RISE) {
if (Y < last) {
dir = FALL;
if (last >= s->white) {
clock[peaks][0] = last;
clock[peaks][1] = i;
peaks++;
if (peaks > 7)
break;
}
}
} else if (dir == FALL) {
if (Y > last && last <= s->black) {
dir = RISE;
}
}
last = Y;
}
if (peaks != 7) {
av_log(ctx, AV_LOG_DEBUG, "peaks: %d != 7\n", peaks);
thresholding(s, src, s->signal, s->unfiltered, s->filtered,
s->avg_filter, s->std_filter,
LAG, 1, 0, inlink->w);
//memcpy(&in->data[0][line * in->linesize[0]], s->signal, inlink->w);
len = periods(s->signal, s->code, inlink->w);
dump_code(ctx, len, line);
if (len < 15 ||
s->code[14].bit != 0 ||
inlink->w / (float)s->code[14].size < SYNC_MIN ||
inlink->w / (float)s->code[14].size > SYNC_MAX) {
return;
}
for (i = 1; i < 7; i++)
max_peak_diff = FFMAX(max_peak_diff, FFABS(clock[i][0] - clock[i-1][0]));
if (max_peak_diff > s->max_peak_diff) {
av_log(ctx, AV_LOG_DEBUG, "mhd: %d > %d\n", max_peak_diff, s->max_peak_diff);
return;
for (i = 14; i < len; i++) {
bit_size += s->code[i].size;
}
max = 0; min = INT_MAX;
for (i = 1; i < 7; i++) {
max = FFMAX(max, FFABS(clock[i][1] - clock[i-1][1]));
min = FFMIN(min, FFABS(clock[i][1] - clock[i-1][1]));
bit_size /= 19.f;
for (i = 1; i < 14; i++) {
if (s->code[i].size > bit_size * 1.5f) {
return;
}
}
range = max - min;
if (range > s->max_period_diff) {
av_log(ctx, AV_LOG_DEBUG, "mpd: %d > %d\n", range, s->max_period_diff);
if (s->code[15].size / bit_size < 0.45f) {
return;
}
s1 = src[sync_width + width_per_bit * 0 + width_per_bit / 2];
s2 = src[sync_width + width_per_bit * 1 + width_per_bit / 2];
s3 = src[sync_width + width_per_bit * 2 + width_per_bit / 2];
for (j = 0, i = 14; i < len; i++) {
int run, bit;
if (FFABS(s1 - s2) > s->max_start_diff || s1 > s->black || s2 > s->black || s3 < s->white) {
av_log(ctx, AV_LOG_DEBUG, "msd: %d > %d\n", FFABS(s1 - s2), s->max_start_diff);
return;
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 = src[sync_width + width_per_bit * (i + 3 + 8 * ch) + width_per_bit / 2];
int b = codes[3 + ch * 8 + i];
if (b - s1 > (s3 - s1) * s->bhd) {
b = 1;
if (b == 255) {
parity++;
b = 1;
} else {
b = 0;
}
......@@ -245,6 +373,10 @@ static void extract_line(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *in
{
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);
......@@ -276,6 +408,12 @@ static av_cold void uninit(AVFilterContext *ctx)
ReadEIA608Context *s = ctx->priv;
av_freep(&s->temp);
av_freep(&s->code);
av_freep(&s->signal);
av_freep(&s->unfiltered);
av_freep(&s->filtered);
av_freep(&s->avg_filter);
av_freep(&s->std_filter);
}
static const AVFilterPad readeia608_inputs[] = {
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment