/* * Copyright (c) 2015 Paul B Mahol * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <tesseract/capi.h> #include "libavutil/opt.h" #include "avfilter.h" #include "formats.h" #include "internal.h" #include "video.h" typedef struct OCRContext { const AVClass *class; char *datapath; char *language; char *whitelist; char *blacklist; TessBaseAPI *tess; } OCRContext; #define OFFSET(x) offsetof(OCRContext, x) #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption ocr_options[] = { { "datapath", "set datapath", OFFSET(datapath), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS }, { "language", "set language", OFFSET(language), AV_OPT_TYPE_STRING, {.str="eng"}, 0, 0, FLAGS }, { "whitelist", "set character whitelist", OFFSET(whitelist), AV_OPT_TYPE_STRING, {.str="0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.:;,-+_!?\"'[]{}()<>|/\\=*&%$#@!~"}, 0, 0, FLAGS }, { "blacklist", "set character blacklist", OFFSET(blacklist), AV_OPT_TYPE_STRING, {.str=""}, 0, 0, FLAGS }, { NULL } }; static av_cold int init(AVFilterContext *ctx) { OCRContext *s = ctx->priv; s->tess = TessBaseAPICreate(); if (TessBaseAPIInit3(s->tess, s->datapath, s->language) == -1) { av_log(ctx, AV_LOG_ERROR, "failed to init tesseract\n"); return AVERROR(EINVAL); } if (!TessBaseAPISetVariable(s->tess, "tessedit_char_whitelist", s->whitelist)) { av_log(ctx, AV_LOG_ERROR, "failed to set whitelist\n"); return AVERROR(EINVAL); } if (!TessBaseAPISetVariable(s->tess, "tessedit_char_blacklist", s->blacklist)) { av_log(ctx, AV_LOG_ERROR, "failed to set blacklist\n"); return AVERROR(EINVAL); } av_log(ctx, AV_LOG_DEBUG, "Tesseract version: %s\n", TessVersion()); return 0; } static int query_formats(AVFilterContext *ctx) { static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_NONE }; AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts); if (!fmts_list) return AVERROR(ENOMEM); return ff_set_common_formats(ctx, fmts_list); } static int filter_frame(AVFilterLink *inlink, AVFrame *in) { AVDictionary **metadata = &in->metadata; AVFilterContext *ctx = inlink->dst; AVFilterLink *outlink = ctx->outputs[0]; OCRContext *s = ctx->priv; char *result; result = TessBaseAPIRect(s->tess, in->data[0], 1, in->linesize[0], 0, 0, in->width, in->height); av_dict_set(metadata, "lavfi.ocr.text", result, 0); TessDeleteText(result); return ff_filter_frame(outlink, in); } static av_cold void uninit(AVFilterContext *ctx) { OCRContext *s = ctx->priv; TessBaseAPIEnd(s->tess); TessBaseAPIDelete(s->tess); } AVFILTER_DEFINE_CLASS(ocr); static const AVFilterPad ocr_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .filter_frame = filter_frame, }, { NULL } }; static const AVFilterPad ocr_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, }, { NULL } }; AVFilter ff_vf_ocr = { .name = "ocr", .description = NULL_IF_CONFIG_SMALL("Optical Character Recognition."), .priv_size = sizeof(OCRContext), .priv_class = &ocr_class, .query_formats = query_formats, .init = init, .uninit = uninit, .inputs = ocr_inputs, .outputs = ocr_outputs, };