From 1bf7bd194bc084309abbdd0b412e70ed1961b851 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Wed, 9 Sep 2015 13:43:35 +0000 Subject: [PATCH] avfilter: add ocr filter Signed-off-by: Paul B Mahol --- Changelog | 1 + configure | 4 ++ doc/filters.texi | 24 +++++++ libavfilter/Makefile | 1 + libavfilter/allfilters.c | 1 + libavfilter/version.h | 2 +- libavfilter/vf_ocr.c | 151 +++++++++++++++++++++++++++++++++++++++ 7 files changed, 183 insertions(+), 1 deletion(-) create mode 100644 libavfilter/vf_ocr.c diff --git a/Changelog b/Changelog index d538c429a1..24d1f05883 100644 --- a/Changelog +++ b/Changelog @@ -4,6 +4,7 @@ releases are sorted from youngest to oldest. version : - DXV decoding - extrastereo filter +- ocr filter version 2.8: diff --git a/configure b/configure index 7c808c27f3..da18e7008f 100755 --- a/configure +++ b/configure @@ -246,6 +246,7 @@ External library support: --enable-libspeex enable Speex de/encoding via libspeex [no] --enable-libssh enable SFTP protocol via libssh [no] --enable-libstagefright-h264 enable H.264 decoding via libstagefright [no] + --enable-libtesseract enable Tesseract, needed for ocr filter [no] --enable-libtheora enable Theora encoding via libtheora [no] --enable-libtwolame enable MP2 encoding via libtwolame [no] --enable-libutvideo enable Ut Video encoding and decoding via libutvideo [no] @@ -1409,6 +1410,7 @@ EXTERNAL_LIBRARY_LIST=" libspeex libssh libstagefright_h264 + libtesseract libtheora libtwolame libutvideo @@ -2774,6 +2776,7 @@ mptestsrc_filter_deps="gpl" negate_filter_deps="lut_filter" perspective_filter_deps="gpl" pp7_filter_deps="gpl" +ocr_filter_deps="libtesseract" ocv_filter_deps="libopencv" owdenoise_filter_deps="gpl" pan_filter_deps="swresample" @@ -5275,6 +5278,7 @@ enabled libspeex && require_pkg_config speex speex/speex.h speex_decode enabled libstagefright_h264 && require_cpp libstagefright_h264 "binder/ProcessState.h media/stagefright/MetaData.h media/stagefright/MediaBufferGroup.h media/stagefright/MediaDebug.h media/stagefright/MediaDefs.h media/stagefright/OMXClient.h media/stagefright/OMXCodec.h" android::OMXClient -lstagefright -lmedia -lutils -lbinder -lgnustl_static +enabled libtesseract && require_pkg_config tesseract tesseract/capi.h TessBaseAPICreate enabled libtheora && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg enabled libtwolame && require libtwolame twolame.h twolame_init -ltwolame && { check_lib twolame.h twolame_encode_buffer_float32_interleaved -ltwolame || diff --git a/doc/filters.texi b/doc/filters.texi index 0b5d898394..930129cb5c 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -7485,6 +7485,30 @@ noise=alls=20:allf=t+u Pass the video source unchanged to the output. +@section ocr +Optical Character Recognition + +This filter uses Tesseract for optical character recognition. + +It accepts the following options: + +@table @option +@item datapath +Set datapath to tesseract data. Default is to use whatever was +set at installation. + +@item language +Set language, default is "eng". + +@item whitelist +Set character whitelist. + +@item blacklist +Set character blacklist. +@end table + +The filter exports recognized text as the frame metadata @code{lavfi.ocr.text}. + @section ocv Apply a video transform using libopencv. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 11a8646d3f..d3e282f67a 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -169,6 +169,7 @@ OBJS-$(CONFIG_NEGATE_FILTER) += vf_lut.o OBJS-$(CONFIG_NOFORMAT_FILTER) += vf_format.o OBJS-$(CONFIG_NOISE_FILTER) += vf_noise.o OBJS-$(CONFIG_NULL_FILTER) += vf_null.o +OBJS-$(CONFIG_OCR_FILTER) += vf_ocr.o OBJS-$(CONFIG_OCV_FILTER) += vf_libopencv.o OBJS-$(CONFIG_OPENCL) += deshake_opencl.o unsharp_opencl.o OBJS-$(CONFIG_OVERLAY_FILTER) += vf_overlay.o dualinput.o framesync.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 9df2d5323f..639e47371f 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -191,6 +191,7 @@ void avfilter_register_all(void) REGISTER_FILTER(NOFORMAT, noformat, vf); REGISTER_FILTER(NOISE, noise, vf); REGISTER_FILTER(NULL, null, vf); + REGISTER_FILTER(OCR, ocr, vf); REGISTER_FILTER(OCV, ocv, vf); REGISTER_FILTER(OVERLAY, overlay, vf); REGISTER_FILTER(OWDENOISE, owdenoise, vf); diff --git a/libavfilter/version.h b/libavfilter/version.h index 87a58360df..e07c4c38ae 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -30,7 +30,7 @@ #include "libavutil/version.h" #define LIBAVFILTER_VERSION_MAJOR 6 -#define LIBAVFILTER_VERSION_MINOR 1 +#define LIBAVFILTER_VERSION_MINOR 2 #define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ diff --git a/libavfilter/vf_ocr.c b/libavfilter/vf_ocr.c new file mode 100644 index 0000000000..870dd68841 --- /dev/null +++ b/libavfilter/vf_ocr.c @@ -0,0 +1,151 @@ +/* + * 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 + +#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, +};