mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
142 lines
4.5 KiB
142 lines
4.5 KiB
/* |
|
* 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 "filters.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 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 |
|
}; |
|
|
|
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; |
|
int *confs; |
|
|
|
result = TessBaseAPIRect(s->tess, in->data[0], 1, |
|
in->linesize[0], 0, 0, in->width, in->height); |
|
confs = TessBaseAPIAllWordConfidences(s->tess); |
|
av_dict_set(metadata, "lavfi.ocr.text", result, 0); |
|
for (int i = 0; confs[i] != -1; i++) { |
|
char number[256]; |
|
|
|
snprintf(number, sizeof(number), "%d ", confs[i]); |
|
av_dict_set(metadata, "lavfi.ocr.confidence", number, AV_DICT_APPEND); |
|
} |
|
|
|
TessDeleteText(result); |
|
TessDeleteIntArray(confs); |
|
|
|
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, |
|
}, |
|
}; |
|
|
|
const AVFilter ff_vf_ocr = { |
|
.name = "ocr", |
|
.description = NULL_IF_CONFIG_SMALL("Optical Character Recognition."), |
|
.priv_size = sizeof(OCRContext), |
|
.priv_class = &ocr_class, |
|
.init = init, |
|
.uninit = uninit, |
|
.flags = AVFILTER_FLAG_METADATA_ONLY, |
|
FILTER_INPUTS(ocr_inputs), |
|
FILTER_OUTPUTS(ff_video_default_filterpad), |
|
FILTER_PIXFMTS_ARRAY(pix_fmts), |
|
};
|
|
|