[FFmpeg-cvslog] avfilter/vf_readeia608: rewrite processing, make extracting more robust
Paul B Mahol
git at videolan.org
Fri Dec 20 19:10:35 EET 2019
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Tue Dec 17 19:47:55 2019 +0100| [786a2daa3de791f685f3113f534201cf85b008d1] | committer: Paul B Mahol
avfilter/vf_readeia608: rewrite processing, make extracting more robust
Lots of options are now obsolete.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=786a2daa3de791f685f3113f534201cf85b008d1
---
doc/filters.texi | 30 +----
libavfilter/vf_readeia608.c | 316 +++++++++++++++++++++++++++++++-------------
2 files changed, 229 insertions(+), 117 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 527c6a08b2..8c5d3a5760 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -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}.
- at 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]}.
-
- at 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]}.
-
- at item mpd
-Set max peaks period difference for sync code detection.
-Default is @code{0.1}. Allowed range is @code{[0.0 - 0.5]}.
-
- at item msd
-Set the first two max start code bits differences.
-Default is @code{0.02}. Allowed range is @code{[0.0 - 0.5]}.
-
- at 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]}.
-
- at item th_w
-Set the white color threshold. Default is @code{0.35}. Allowed range is @code{[0.1 - 1]}.
-
- at 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
diff --git a/libavfilter/vf_readeia608.c b/libavfilter/vf_readeia608.c
index 27a0c58321..0ddc7bfd50 100644
--- a/libavfilter/vf_readeia608.c
+++ b/libavfilter/vf_readeia608.c
@@ -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[] = {
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