blob: 870dd688410e5821e4043aeb68472a8bc4ca5a20
| 1 | /* |
| 2 | * Copyright (c) 2015 Paul B Mahol |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #include <tesseract/capi.h> |
| 22 | |
| 23 | #include "libavutil/opt.h" |
| 24 | #include "avfilter.h" |
| 25 | #include "formats.h" |
| 26 | #include "internal.h" |
| 27 | #include "video.h" |
| 28 | |
| 29 | typedef struct OCRContext { |
| 30 | const AVClass *class; |
| 31 | |
| 32 | char *datapath; |
| 33 | char *language; |
| 34 | char *whitelist; |
| 35 | char *blacklist; |
| 36 | |
| 37 | TessBaseAPI *tess; |
| 38 | } OCRContext; |
| 39 | |
| 40 | #define OFFSET(x) offsetof(OCRContext, x) |
| 41 | #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
| 42 | |
| 43 | static const AVOption ocr_options[] = { |
| 44 | { "datapath", "set datapath", OFFSET(datapath), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS }, |
| 45 | { "language", "set language", OFFSET(language), AV_OPT_TYPE_STRING, {.str="eng"}, 0, 0, FLAGS }, |
| 46 | { "whitelist", "set character whitelist", OFFSET(whitelist), AV_OPT_TYPE_STRING, {.str="0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.:;,-+_!?\"'[]{}()<>|/\\=*&%$#@!~"}, 0, 0, FLAGS }, |
| 47 | { "blacklist", "set character blacklist", OFFSET(blacklist), AV_OPT_TYPE_STRING, {.str=""}, 0, 0, FLAGS }, |
| 48 | { NULL } |
| 49 | }; |
| 50 | |
| 51 | static av_cold int init(AVFilterContext *ctx) |
| 52 | { |
| 53 | OCRContext *s = ctx->priv; |
| 54 | |
| 55 | s->tess = TessBaseAPICreate(); |
| 56 | if (TessBaseAPIInit3(s->tess, s->datapath, s->language) == -1) { |
| 57 | av_log(ctx, AV_LOG_ERROR, "failed to init tesseract\n"); |
| 58 | return AVERROR(EINVAL); |
| 59 | } |
| 60 | |
| 61 | if (!TessBaseAPISetVariable(s->tess, "tessedit_char_whitelist", s->whitelist)) { |
| 62 | av_log(ctx, AV_LOG_ERROR, "failed to set whitelist\n"); |
| 63 | return AVERROR(EINVAL); |
| 64 | } |
| 65 | |
| 66 | if (!TessBaseAPISetVariable(s->tess, "tessedit_char_blacklist", s->blacklist)) { |
| 67 | av_log(ctx, AV_LOG_ERROR, "failed to set blacklist\n"); |
| 68 | return AVERROR(EINVAL); |
| 69 | } |
| 70 | |
| 71 | av_log(ctx, AV_LOG_DEBUG, "Tesseract version: %s\n", TessVersion()); |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | static int query_formats(AVFilterContext *ctx) |
| 77 | { |
| 78 | static const enum AVPixelFormat pix_fmts[] = { |
| 79 | AV_PIX_FMT_GRAY8, |
| 80 | AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P, |
| 81 | AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, |
| 82 | AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P, |
| 83 | AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, |
| 84 | AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P, |
| 85 | AV_PIX_FMT_YUVJ411P, |
| 86 | AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P, |
| 87 | AV_PIX_FMT_NONE |
| 88 | }; |
| 89 | |
| 90 | AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts); |
| 91 | if (!fmts_list) |
| 92 | return AVERROR(ENOMEM); |
| 93 | ff_set_common_formats(ctx, fmts_list); |
| 94 | |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
| 99 | { |
| 100 | AVDictionary **metadata = avpriv_frame_get_metadatap(in); |
| 101 | AVFilterContext *ctx = inlink->dst; |
| 102 | AVFilterLink *outlink = ctx->outputs[0]; |
| 103 | OCRContext *s = ctx->priv; |
| 104 | char *result; |
| 105 | |
| 106 | result = TessBaseAPIRect(s->tess, in->data[0], 1, |
| 107 | in->linesize[0], 0, 0, in->width, in->height); |
| 108 | av_dict_set(metadata, "lavfi.ocr.text", result, 0); |
| 109 | TessDeleteText(result); |
| 110 | |
| 111 | return ff_filter_frame(outlink, in); |
| 112 | } |
| 113 | |
| 114 | static av_cold void uninit(AVFilterContext *ctx) |
| 115 | { |
| 116 | OCRContext *s = ctx->priv; |
| 117 | |
| 118 | TessBaseAPIEnd(s->tess); |
| 119 | TessBaseAPIDelete(s->tess); |
| 120 | } |
| 121 | |
| 122 | AVFILTER_DEFINE_CLASS(ocr); |
| 123 | |
| 124 | static const AVFilterPad ocr_inputs[] = { |
| 125 | { |
| 126 | .name = "default", |
| 127 | .type = AVMEDIA_TYPE_VIDEO, |
| 128 | .filter_frame = filter_frame, |
| 129 | }, |
| 130 | { NULL } |
| 131 | }; |
| 132 | |
| 133 | static const AVFilterPad ocr_outputs[] = { |
| 134 | { |
| 135 | .name = "default", |
| 136 | .type = AVMEDIA_TYPE_VIDEO, |
| 137 | }, |
| 138 | { NULL } |
| 139 | }; |
| 140 | |
| 141 | AVFilter ff_vf_ocr = { |
| 142 | .name = "ocr", |
| 143 | .description = NULL_IF_CONFIG_SMALL("Optical Character Recognition."), |
| 144 | .priv_size = sizeof(OCRContext), |
| 145 | .priv_class = &ocr_class, |
| 146 | .query_formats = query_formats, |
| 147 | .init = init, |
| 148 | .uninit = uninit, |
| 149 | .inputs = ocr_inputs, |
| 150 | .outputs = ocr_outputs, |
| 151 | }; |
| 152 |