| /* |
| * 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); |
| ff_set_common_formats(ctx, fmts_list); |
| |
| return 0; |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
| { |
| AVDictionary **metadata = avpriv_frame_get_metadatap(in); |
| 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, |
| }; |