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554 lines
17 KiB
554 lines
17 KiB
/* |
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* Copyright (c) 2017 Paul B Mahol |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* Filter for reading closed captioning data (EIA-608). |
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* See also https://en.wikipedia.org/wiki/EIA-608 |
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*/ |
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#include <string.h> |
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#include "libavutil/internal.h" |
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#include "libavutil/mem.h" |
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#include "libavutil/opt.h" |
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#include "libavutil/pixdesc.h" |
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#include "avfilter.h" |
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#include "filters.h" |
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#include "video.h" |
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#define LAG 25 |
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#define CLOCK_BITSIZE_MIN 0.2f |
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#define CLOCK_BITSIZE_MAX 1.5f |
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#define SYNC_BITSIZE_MIN 12.f |
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#define SYNC_BITSIZE_MAX 15.f |
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typedef struct LineItem { |
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int input; |
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int output; |
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float unfiltered; |
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float filtered; |
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float average; |
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float deviation; |
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} LineItem; |
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typedef struct CodeItem { |
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uint8_t bit; |
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int size; |
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} CodeItem; |
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typedef struct ScanItem { |
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int nb_line; |
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int found; |
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int white; |
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int black; |
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uint64_t *histogram; |
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uint8_t byte[2]; |
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CodeItem *code; |
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LineItem *line; |
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} ScanItem; |
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typedef struct ReadEIA608Context { |
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const AVClass *class; |
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int start, end; |
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float spw; |
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int chp; |
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int lp; |
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int depth; |
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int max; |
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int nb_allocated; |
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ScanItem *scan; |
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void (*read_line[2])(AVFrame *in, int nb_line, |
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LineItem *line, int lp, int w); |
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} ReadEIA608Context; |
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#define OFFSET(x) offsetof(ReadEIA608Context, x) |
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#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM |
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static const AVOption readeia608_options[] = { |
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{ "scan_min", "set from which line to scan for codes", OFFSET(start), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS }, |
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{ "scan_max", "set to which line to scan for codes", OFFSET(end), AV_OPT_TYPE_INT, {.i64=29}, 0, INT_MAX, FLAGS }, |
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{ "spw", "set ratio of width reserved for sync code detection", OFFSET(spw), AV_OPT_TYPE_FLOAT, {.dbl=.27}, 0.1, 0.7, FLAGS }, |
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{ "chp", "check and apply parity bit", OFFSET(chp), AV_OPT_TYPE_BOOL, {.i64= 0}, 0, 1, FLAGS }, |
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{ "lp", "lowpass line prior to processing", OFFSET(lp), AV_OPT_TYPE_BOOL, {.i64= 1}, 0, 1, FLAGS }, |
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{ NULL } |
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}; |
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AVFILTER_DEFINE_CLASS(readeia608); |
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static const enum AVPixelFormat pixel_fmts[] = { |
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AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, |
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AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, |
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AV_PIX_FMT_GRAY16, |
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AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P, |
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AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, |
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AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P, |
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AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, |
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AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P, |
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AV_PIX_FMT_YUVJ411P, |
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AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9, |
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AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10, |
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AV_PIX_FMT_YUV440P10, |
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AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12, |
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AV_PIX_FMT_YUV440P12, |
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AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14, |
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AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16, |
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AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P, |
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AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_YUVA444P16, |
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AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA422P16, |
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AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA420P16, |
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AV_PIX_FMT_NONE |
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}; |
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static int config_filter(AVFilterContext *ctx, int start, int end) |
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{ |
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ReadEIA608Context *s = ctx->priv; |
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AVFilterLink *inlink = ctx->inputs[0]; |
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int size = inlink->w + LAG; |
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if (end >= inlink->h) { |
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av_log(ctx, AV_LOG_WARNING, "Last line to scan too large, clipping.\n"); |
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end = inlink->h - 1; |
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} |
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if (start > end) { |
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av_log(ctx, AV_LOG_ERROR, "Invalid range.\n"); |
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return AVERROR(EINVAL); |
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} |
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if (s->nb_allocated < end - start + 1) { |
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const int diff = end - start + 1 - s->nb_allocated; |
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s->scan = av_realloc_f(s->scan, end - start + 1, sizeof(*s->scan)); |
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if (!s->scan) |
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return AVERROR(ENOMEM); |
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memset(&s->scan[s->nb_allocated], 0, diff * sizeof(*s->scan)); |
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s->nb_allocated = end - start + 1; |
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} |
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for (int i = 0; i < s->nb_allocated; i++) { |
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ScanItem *scan = &s->scan[i]; |
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if (!scan->histogram) |
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scan->histogram = av_calloc(s->max + 1, sizeof(*scan->histogram)); |
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if (!scan->line) |
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scan->line = av_calloc(size, sizeof(*scan->line)); |
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if (!scan->code) |
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scan->code = av_calloc(size, sizeof(*scan->code)); |
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if (!scan->line || !scan->code || !scan->histogram) |
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return AVERROR(ENOMEM); |
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} |
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s->start = start; |
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s->end = end; |
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return 0; |
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} |
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static void build_histogram(ReadEIA608Context *s, ScanItem *scan, const LineItem *line, int len) |
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{ |
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memset(scan->histogram, 0, (s->max + 1) * sizeof(*scan->histogram)); |
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for (int i = LAG; i < len + LAG; i++) |
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scan->histogram[line[i].input]++; |
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} |
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static void find_black_and_white(ReadEIA608Context *s, ScanItem *scan) |
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{ |
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const int max = s->max; |
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int start = 0, end = 0, middle; |
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int black = 0, white = 0; |
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int cnt; |
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for (int i = 0; i <= max; i++) { |
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if (scan->histogram[i]) { |
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start = i; |
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break; |
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} |
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} |
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for (int i = max; i >= 0; i--) { |
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if (scan->histogram[i]) { |
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end = i; |
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break; |
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} |
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} |
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middle = start + (end - start) / 2; |
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cnt = 0; |
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for (int i = start; i <= middle; i++) { |
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if (scan->histogram[i] > cnt) { |
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cnt = scan->histogram[i]; |
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black = i; |
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} |
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} |
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cnt = 0; |
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for (int i = end; i >= middle; i--) { |
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if (scan->histogram[i] > cnt) { |
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cnt = scan->histogram[i]; |
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white = i; |
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} |
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} |
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scan->black = black; |
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scan->white = white; |
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} |
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static float meanf(const LineItem *line, int len) |
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{ |
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float sum = 0.0, mean = 0.0; |
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for (int i = 0; i < len; i++) |
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sum += line[i].filtered; |
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mean = sum / len; |
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return mean; |
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} |
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static float stddevf(const LineItem *line, int len) |
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{ |
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float m = meanf(line, len); |
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float standard_deviation = 0.f; |
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for (int i = 0; i < len; i++) |
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standard_deviation += (line[i].filtered - m) * (line[i].filtered - m); |
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return sqrtf(standard_deviation / (len - 1)); |
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} |
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static void thresholding(ReadEIA608Context *s, ScanItem *scan, LineItem *line, |
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int lag, float threshold, float influence, int len) |
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{ |
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for (int i = lag; i < len + lag; i++) { |
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line[i].unfiltered = line[i].input / 255.f; |
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line[i].filtered = line[i].unfiltered; |
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} |
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for (int i = 0; i < lag; i++) { |
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line[i].unfiltered = meanf(line, len * s->spw); |
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line[i].filtered = line[i].unfiltered; |
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} |
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line[lag - 1].average = meanf(line, lag); |
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line[lag - 1].deviation = stddevf(line, lag); |
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for (int i = lag; i < len + lag; i++) { |
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if (fabsf(line[i].unfiltered - line[i-1].average) > threshold * line[i-1].deviation) { |
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if (line[i].unfiltered > line[i-1].average) { |
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line[i].output = 255; |
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} else { |
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line[i].output = 0; |
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} |
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line[i].filtered = influence * line[i].unfiltered + (1.f - influence) * line[i-1].filtered; |
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} else { |
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int distance_from_black, distance_from_white; |
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distance_from_black = FFABS(line[i].input - scan->black); |
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distance_from_white = FFABS(line[i].input - scan->white); |
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line[i].output = distance_from_black <= distance_from_white ? 0 : 255; |
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} |
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line[i].average = meanf(line + i - lag, lag); |
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line[i].deviation = stddevf(line + i - lag, lag); |
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} |
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} |
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static int periods(const LineItem *line, CodeItem *code, int len) |
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{ |
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int hold = line[LAG].output, cnt = 0; |
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int last = LAG; |
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memset(code, 0, len * sizeof(*code)); |
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for (int i = LAG + 1; i < len + LAG; i++) { |
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if (line[i].output != hold) { |
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code[cnt].size = i - last; |
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code[cnt].bit = hold; |
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hold = line[i].output; |
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last = i; |
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cnt++; |
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} |
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} |
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code[cnt].size = LAG + len - last; |
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code[cnt].bit = hold; |
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return cnt + 1; |
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} |
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static void dump_code(AVFilterContext *ctx, ScanItem *scan, int len, int item) |
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{ |
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av_log(ctx, AV_LOG_DEBUG, "%d:", item); |
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for (int i = 0; i < len; i++) { |
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av_log(ctx, AV_LOG_DEBUG, " %03d", scan->code[i].size); |
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} |
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av_log(ctx, AV_LOG_DEBUG, "\n"); |
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} |
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#define READ_LINE(type, name) \ |
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static void read_##name(AVFrame *in, int nb_line, LineItem *line, int lp, int w) \ |
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{ \ |
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const type *src = (const type *)(&in->data[0][nb_line * in->linesize[0]]);\ |
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\ |
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if (lp) { \ |
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for (int i = 0; i < w; i++) { \ |
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int a = FFMAX(i - 3, 0); \ |
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int b = FFMAX(i - 2, 0); \ |
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int c = FFMAX(i - 1, 0); \ |
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int d = FFMIN(i + 3, w-1); \ |
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int e = FFMIN(i + 2, w-1); \ |
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int f = FFMIN(i + 1, w-1); \ |
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\ |
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line[LAG + i].input = (src[a] + src[b] + src[c] + src[i] + \ |
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src[d] + src[e] + src[f] + 6) / 7; \ |
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} \ |
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} else { \ |
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for (int i = 0; i < w; i++) { \ |
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line[LAG + i].input = src[i]; \ |
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} \ |
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} \ |
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} |
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READ_LINE(uint8_t, byte) |
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READ_LINE(uint16_t, word) |
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static int config_input(AVFilterLink *inlink) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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ReadEIA608Context *s = ctx->priv; |
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const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); |
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if (!desc) |
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return AVERROR_BUG; |
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s->depth = desc->comp[0].depth; |
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s->max = (1 << desc->comp[0].depth) - 1; |
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s->read_line[0] = read_byte; |
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s->read_line[1] = read_word; |
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return config_filter(ctx, s->start, s->end); |
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} |
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static void extract_line(AVFilterContext *ctx, AVFrame *in, ScanItem *scan, int w, int nb_line) |
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{ |
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ReadEIA608Context *s = ctx->priv; |
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LineItem *line = scan->line; |
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int i, j, ch, len; |
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uint8_t codes[19] = { 0 }; |
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float bit_size = 0.f; |
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int parity; |
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memset(line, 0, (w + LAG) * sizeof(*line)); |
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scan->byte[0] = scan->byte[1] = 0; |
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scan->found = 0; |
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s->read_line[s->depth > 8](in, nb_line, line, s->lp, w); |
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build_histogram(s, scan, line, w); |
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find_black_and_white(s, scan); |
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if (scan->white - scan->black < 5) |
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return; |
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thresholding(s, scan, line, LAG, 1, 0, w); |
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len = periods(line, scan->code, w); |
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dump_code(ctx, scan, len, nb_line); |
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if (len < 15 || |
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scan->code[14].bit != 0 || |
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w / (float)scan->code[14].size < SYNC_BITSIZE_MIN || |
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w / (float)scan->code[14].size > SYNC_BITSIZE_MAX) { |
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return; |
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} |
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for (i = 14; i < len; i++) { |
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bit_size += scan->code[i].size; |
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} |
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bit_size /= 19.f; |
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for (i = 1; i < 14; i++) { |
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if (scan->code[i].size / bit_size > CLOCK_BITSIZE_MAX || |
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scan->code[i].size / bit_size < CLOCK_BITSIZE_MIN) { |
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return; |
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} |
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} |
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if (scan->code[15].size / bit_size < 0.45f) { |
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return; |
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} |
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for (j = 0, i = 14; i < len; i++) { |
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int run, bit; |
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run = lrintf(scan->code[i].size / bit_size); |
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bit = scan->code[i].bit; |
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for (int k = 0; j < 19 && k < run; k++) { |
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codes[j++] = bit; |
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} |
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if (j >= 19) |
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break; |
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} |
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for (ch = 0; ch < 2; ch++) { |
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for (parity = 0, i = 0; i < 8; i++) { |
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int b = codes[3 + ch * 8 + i]; |
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if (b == 255) { |
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parity++; |
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b = 1; |
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} else { |
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b = 0; |
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} |
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scan->byte[ch] |= b << i; |
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} |
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if (s->chp) { |
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if (!(parity & 1)) { |
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scan->byte[ch] = 0x7F; |
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} |
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} |
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} |
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scan->nb_line = nb_line; |
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scan->found = 1; |
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} |
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static int extract_lines(AVFilterContext *ctx, void *arg, |
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int job, int nb_jobs) |
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{ |
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ReadEIA608Context *s = ctx->priv; |
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AVFilterLink *inlink = ctx->inputs[0]; |
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const int h = s->end - s->start + 1; |
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const int start = (h * job) / nb_jobs; |
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const int end = (h * (job+1)) / nb_jobs; |
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AVFrame *in = arg; |
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for (int i = start; i < end; i++) { |
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ScanItem *scan = &s->scan[i]; |
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extract_line(ctx, in, scan, inlink->w, s->start + i); |
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} |
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return 0; |
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} |
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static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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ReadEIA608Context *s = ctx->priv; |
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int nb_found; |
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ff_filter_execute(ctx, extract_lines, in, NULL, |
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FFMIN(FFMAX(s->end - s->start + 1, 1), ff_filter_get_nb_threads(ctx))); |
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nb_found = 0; |
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for (int i = 0; i < s->end - s->start + 1; i++) { |
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ScanItem *scan = &s->scan[i]; |
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uint8_t key[128], value[128]; |
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if (!scan->found) |
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continue; |
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//snprintf(key, sizeof(key), "lavfi.readeia608.%d.bits", nb_found); |
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//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); |
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//av_dict_set(&in->metadata, key, value, 0); |
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snprintf(key, sizeof(key), "lavfi.readeia608.%d.cc", nb_found); |
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snprintf(value, sizeof(value), "0x%02X%02X", scan->byte[0], scan->byte[1]); |
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av_dict_set(&in->metadata, key, value, 0); |
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snprintf(key, sizeof(key), "lavfi.readeia608.%d.line", nb_found); |
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av_dict_set_int(&in->metadata, key, scan->nb_line, 0); |
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nb_found++; |
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} |
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return ff_filter_frame(outlink, in); |
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} |
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static av_cold void uninit(AVFilterContext *ctx) |
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{ |
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ReadEIA608Context *s = ctx->priv; |
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for (int i = 0; i < s->nb_allocated; i++) { |
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ScanItem *scan = &s->scan[i]; |
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av_freep(&scan->histogram); |
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av_freep(&scan->code); |
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av_freep(&scan->line); |
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} |
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s->nb_allocated = 0; |
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av_freep(&s->scan); |
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} |
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static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, |
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char *res, int res_len, int flags) |
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{ |
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ReadEIA608Context *s = ctx->priv; |
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int ret, start = s->start, end = s->end; |
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ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags); |
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if (ret < 0) |
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return ret; |
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ret = config_filter(ctx, s->start, s->end); |
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if (ret < 0) { |
|
s->start = start; |
|
s->end = end; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static const AVFilterPad readeia608_inputs[] = { |
|
{ |
|
.name = "default", |
|
.type = AVMEDIA_TYPE_VIDEO, |
|
.filter_frame = filter_frame, |
|
.config_props = config_input, |
|
}, |
|
}; |
|
|
|
const 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, |
|
FILTER_INPUTS(readeia608_inputs), |
|
FILTER_OUTPUTS(ff_video_default_filterpad), |
|
FILTER_PIXFMTS_ARRAY(pixel_fmts), |
|
.uninit = uninit, |
|
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | |
|
AVFILTER_FLAG_SLICE_THREADS | |
|
AVFILTER_FLAG_METADATA_ONLY, |
|
.process_command = process_command, |
|
};
|
|
|