mirror of
https://git.videolan.org/git/ffmpeg.git
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152 lines
4.5 KiB
C
152 lines
4.5 KiB
C
/*
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* Copyright (c) 2015 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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#include <tesseract/capi.h>
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#include "libavutil/opt.h"
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#include "avfilter.h"
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#include "formats.h"
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#include "internal.h"
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#include "video.h"
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typedef struct OCRContext {
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const AVClass *class;
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char *datapath;
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char *language;
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char *whitelist;
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char *blacklist;
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TessBaseAPI *tess;
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} OCRContext;
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#define OFFSET(x) offsetof(OCRContext, x)
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#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
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static const AVOption ocr_options[] = {
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{ "datapath", "set datapath", OFFSET(datapath), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
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{ "language", "set language", OFFSET(language), AV_OPT_TYPE_STRING, {.str="eng"}, 0, 0, FLAGS },
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{ "whitelist", "set character whitelist", OFFSET(whitelist), AV_OPT_TYPE_STRING, {.str="0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.:;,-+_!?\"'[]{}()<>|/\\=*&%$#@!~"}, 0, 0, FLAGS },
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{ "blacklist", "set character blacklist", OFFSET(blacklist), AV_OPT_TYPE_STRING, {.str=""}, 0, 0, FLAGS },
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{ NULL }
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};
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static av_cold int init(AVFilterContext *ctx)
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{
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OCRContext *s = ctx->priv;
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s->tess = TessBaseAPICreate();
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if (TessBaseAPIInit3(s->tess, s->datapath, s->language) == -1) {
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av_log(ctx, AV_LOG_ERROR, "failed to init tesseract\n");
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return AVERROR(EINVAL);
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}
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if (!TessBaseAPISetVariable(s->tess, "tessedit_char_whitelist", s->whitelist)) {
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av_log(ctx, AV_LOG_ERROR, "failed to set whitelist\n");
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return AVERROR(EINVAL);
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}
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if (!TessBaseAPISetVariable(s->tess, "tessedit_char_blacklist", s->blacklist)) {
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av_log(ctx, AV_LOG_ERROR, "failed to set blacklist\n");
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return AVERROR(EINVAL);
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}
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av_log(ctx, AV_LOG_DEBUG, "Tesseract version: %s\n", TessVersion());
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return 0;
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}
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static int query_formats(AVFilterContext *ctx)
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{
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static const enum AVPixelFormat pix_fmts[] = {
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AV_PIX_FMT_GRAY8,
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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_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
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AV_PIX_FMT_NONE
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};
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AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
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if (!fmts_list)
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return AVERROR(ENOMEM);
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ff_set_common_formats(ctx, fmts_list);
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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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AVDictionary **metadata = &in->metadata;
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AVFilterContext *ctx = inlink->dst;
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AVFilterLink *outlink = ctx->outputs[0];
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OCRContext *s = ctx->priv;
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char *result;
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result = TessBaseAPIRect(s->tess, in->data[0], 1,
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in->linesize[0], 0, 0, in->width, in->height);
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av_dict_set(metadata, "lavfi.ocr.text", result, 0);
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TessDeleteText(result);
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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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OCRContext *s = ctx->priv;
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TessBaseAPIEnd(s->tess);
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TessBaseAPIDelete(s->tess);
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}
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AVFILTER_DEFINE_CLASS(ocr);
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static const AVFilterPad ocr_inputs[] = {
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{
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.name = "default",
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.type = AVMEDIA_TYPE_VIDEO,
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.filter_frame = filter_frame,
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},
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{ NULL }
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};
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static const AVFilterPad ocr_outputs[] = {
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{
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.name = "default",
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.type = AVMEDIA_TYPE_VIDEO,
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},
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{ NULL }
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};
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AVFilter ff_vf_ocr = {
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.name = "ocr",
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.description = NULL_IF_CONFIG_SMALL("Optical Character Recognition."),
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.priv_size = sizeof(OCRContext),
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.priv_class = &ocr_class,
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.query_formats = query_formats,
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.init = init,
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.uninit = uninit,
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.inputs = ocr_inputs,
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.outputs = ocr_outputs,
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};
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