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Code Issues Releases Activity

avfilter/vf_readeia608: use special struct to hold line items

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This commit is contained in:
Paul B Mahol 2019-12-23 12:28:30 +01:00
parent 0115dbd043
commit 16968b619d
1 changed files with 70 additions and 78 deletions
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148
libavfilter/vf_readeia608.c
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@ -40,6 +40,16 @@
#define SYNC_MIN 12.f
#define SYNC_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;
@ -57,13 +67,8 @@ typedef struct ReadEIA608Context {
uint64_t histogram[256];
uint8_t *temp;
uint8_t *signal;
CodeItem *code;
float *unfiltered;
float *filtered;
float *avg_filter;
float *std_filter;
LineItem *line;
} ReadEIA608Context;
#define OFFSET(x) offsetof(ReadEIA608Context, x)
@ -114,26 +119,20 @@ static int config_input(AVFilterLink *inlink)
return AVERROR(EINVAL);
}
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->line = av_calloc(size, sizeof(*s->line));
s->code = av_calloc(size, sizeof(*s->code));
s->temp = av_calloc(size, sizeof(*s->temp));
if (!s->unfiltered || !s->filtered || !s->avg_filter ||
!s->std_filter || !s->signal || !s->code || !s->temp)
if (!s->line || !s->code)
return AVERROR(ENOMEM);
return 0;
}
static void build_histogram(ReadEIA608Context *s, const uint8_t *src, int len)
static void build_histogram(ReadEIA608Context *s, const LineItem *line, int len)
{
memset(s->histogram, 0, sizeof(s->histogram));
for (int i = 0; i < len; i++)
s->histogram[src[i]]++;
for (int i = LAG; i < len + LAG; i++)
s->histogram[line[i].input]++;
}
static void find_black_and_white(ReadEIA608Context *s)
@ -178,87 +177,86 @@ static void find_black_and_white(ReadEIA608Context *s)
s->white = white;
}
static float meanf(float *data, int len)
static float meanf(const LineItem *line, int len)
{
float sum = 0.0, mean = 0.0;
for (int i = 0; i < len; i++)
sum += data[i];
sum += line[i].filtered;
mean = sum / len;
return mean;
}
static float stddevf(float *data, int len)
static float stddevf(const LineItem *line, int len)
{
float m = meanf(data, len);
float m = meanf(line, len);
float standard_deviation = 0.f;
for (int i = 0; i < len; i++)
standard_deviation += (data[i] - m) * (data[i] - m);
standard_deviation += (line[i].filtered - m) * (line[i].filtered - 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,
static void thresholding(ReadEIA608Context *s, LineItem *line,
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];
line[i].unfiltered = line[i].input / 255.f;
line[i].filtered = line[i].unfiltered;
}
for (int i = 0; i < lag; i++) {
unfiltered[i] = meanf(unfiltered, len * s->spw);
filtered[i] = unfiltered[i];
line[i].unfiltered = meanf(line, len * s->spw);
line[i].filtered = line[i].unfiltered;
}
memset(signal, 0, len);
avg_filter[lag - 1] = meanf(unfiltered, lag);
std_filter[lag - 1] = stddevf(unfiltered, lag);
line[lag - 1].average = meanf(line, lag);
line[lag - 1].deviation = stddevf(line, 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;
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 {
signal[i - lag] = 0;
line[i].output = 0;
}
filtered[i] = influence * unfiltered[i] + (1.f - influence) * filtered[i-1];
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(y[i - lag] - s->black);
distance_from_white = FFABS(y[i - lag] - s->white);
distance_from_black = FFABS(line[i].input - s->black);
distance_from_white = FFABS(line[i].input - s->white);
signal[i - lag] = distance_from_black <= distance_from_white ? 0 : 255;
line[i].output = distance_from_black <= distance_from_white ? 0 : 255;
}
avg_filter[i] = meanf(filtered + i - lag, lag);
std_filter[i] = stddevf(filtered + i - lag, lag);
line[i].average = meanf(line + i - lag, lag);
line[i].deviation = stddevf(line + i - lag, lag);
}
}
static int periods(const uint8_t *signal, CodeItem *code, int len)
static int periods(const LineItem *line, CodeItem *code, int len)
{
int hold = signal[0], cnt = 0;
int last = 0;
int hold = line[LAG].output, cnt = 0;
int last = LAG;
memset(code, 0, len * sizeof(*code));
for (int i = 1; i < len; i++) {
if (signal[i] != hold) {
for (int i = LAG + 1; i < len + LAG; i++) {
if (line[i].output != hold) {
code[cnt].size = i - last;
code[cnt].bit = hold;
hold = signal[i];
hold = line[i].output;
last = i;
cnt++;
}
}
code[cnt].size = len - last;
code[cnt].size = LAG + len - last;
code[cnt].bit = hold;
return cnt + 1;
@ -275,9 +273,10 @@ static void dump_code(AVFilterContext *ctx, int len, int item)
av_log(ctx, AV_LOG_DEBUG, "\n");
}
static void extract_line(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *in, int line)
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 };
@ -285,40 +284,38 @@ static void extract_line(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *in
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;
memset(line, 0, (w + LAG) * sizeof(*line));
for (i = 0; i < inlink->w; i++) {
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);
int e = FFMIN(i + 2, w);
int f = FFMIN(i + 1, w);
int d = FFMIN(i + 3, w-1);
int e = FFMIN(i + 2, w-1);
int f = FFMIN(i + 1, w-1);
dst[i] = (src[a] + src[b] + src[c] + src[i] + src[d] + src[e] + src[f] + 6) / 7;
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];
}
src = s->temp;
}
build_histogram(s, src, inlink->w);
build_histogram(s, line, w);
find_black_and_white(s);
if (s->white - s->black < 5)
return;
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);
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 ||
inlink->w / (float)s->code[14].size < SYNC_MIN ||
inlink->w / (float)s->code[14].size > SYNC_MAX) {
w / (float)s->code[14].size < SYNC_MIN ||
w / (float)s->code[14].size > SYNC_MAX) {
return;
}
@ -383,7 +380,7 @@ static void extract_line(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *in
av_dict_set(&in->metadata, key, value, 0);
snprintf(key, sizeof(key), "lavfi.readeia608.%d.line", s->nb_found);
snprintf(value, sizeof(value), "%d", line);
snprintf(value, sizeof(value), "%d", nb_line);
av_dict_set(&in->metadata, key, value, 0);
}
@ -399,7 +396,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
s->nb_found = 0;
for (i = s->start; i <= s->end; i++)
extract_line(ctx, inlink, in, i);
extract_line(ctx, in, inlink->w, i);
return ff_filter_frame(outlink, in);
}
@ -408,13 +405,8 @@ 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);
av_freep(&s->line);
}
static const AVFilterPad readeia608_inputs[] = {