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AQHX8Hrg8AyHJcafRUSlPLBq99AOiw== Date: Mon, 13 Dec 2021 23:40:56 +0000 Message-ID: References: <1ef42eb01b3627bbad539abd46206f320bb39697.1639438462.git.softworkz@hotmail.com> <4148d77a82d4b7e229fc81ce9bc1bc06904533f1.1639438462.git.softworkz@hotmail.com> <2ac798924ee984010d2e85f00bc992d9aa106171.1639438462.git.softworkz@hotmail.com> <300ea7188b331ca5e00dd7e04c03df8aba2a99c0.1639438462.git.softworkz@hotmail.com> <9474726b26f0d3e8f353d07caed2fbd33cdf473a.1639438462.git.softworkz@hotmail.com> <424522c96b5cdf6b03faa6bdceb1d25449463429.1639438462.git.softworkz@hotmail.com> <90caff245055005e6a4a890b3665da55aa853b31.1639438462.git.softworkz@hotmail.com> <0ebcf3ed2adb02d3ffb243a499b434c3bdd976a7.1639438462.git.softworkz@hotmail.com> <4b5c1c1185075fd6e5d8ef70e07fdce6f896d699.1639438462.git.softworkz@hotmail.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-tmn: [jVPCuWvgdN6TeSxNgSBaO/oPmARjAsjX] 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avfilter/splitcc: Add splitcc filter for closed caption handling X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: dwlBcIskhExs - splitcc {V -> VS) Extract closed-caption (A53) data from video frames as subtitle Frames ffmpeg -y -loglevel verbose -i "https://streams.videolan.org/streams/ts/CC/NewsStream-608-ac3.ts" -filter_complex "[0:v]splitcc[vid1],textmod=mode=remove_chars:find='@',[vid1]overlay_textsubs" output.mkv Signed-off-by: softworkz --- configure | 1 + doc/filters.texi | 63 +++++++ libavfilter/Makefile | 1 + libavfilter/allfilters.c | 1 + libavfilter/sf_splitcc.c | 378 +++++++++++++++++++++++++++++++++++++++ 5 files changed, 444 insertions(+) create mode 100644 libavfilter/sf_splitcc.c diff --git a/configure b/configure index 7f67a62b08..a6dad8fe9d 100755 --- a/configure +++ b/configure @@ -3704,6 +3704,7 @@ spp_filter_select="fft idctdsp fdctdsp me_cmp pixblockdsp" sr_filter_deps="avformat swscale" sr_filter_select="dnn" stereo3d_filter_deps="gpl" +splitcc_filter_deps="avcodec" subtitles_filter_deps="avformat avcodec libass" super2xsai_filter_deps="gpl" pixfmts_super2xsai_test_deps="super2xsai_filter" diff --git a/doc/filters.texi b/doc/filters.texi index 4806132cc1..53c7e91ef3 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -26130,6 +26130,69 @@ ffmpeg -i INPUT -filter_complex "showspeaker=format=colon:style='@{\\c&HDD0000&\ @end example @end itemize + +@section splitcc + +Split-out closed-caption/A53 subtitles from video frame side data. + +This filter provides an input and an output for video frames, which are just passed through without modification. +The second out provides subtitle frames which are extracted from video frame side data. + +Inputs: +@itemize +@item 0: Video [ALL] +@end itemize + +Outputs: +@itemize +@item 0: Video (same as input) +@item 1: Subtitles [TEXT] +@end itemize + +It accepts the following parameters: + +@table @option + +@item use_cc_styles +Emit closed caption style header. +This will make closed captions appear in white font with a black rectangle background. + +@item real_time +Emit subtitle events as they are decoded for real-time display. + +@item real_time_latency_msec +Minimum elapsed time between emitting real-time subtitle events. +Only applies to real_time mode. + +@item data_field +Select data field. Possible values: + +@table @samp +@item auto +Pick first one that appears. +@item first +@item second +@end table + +@end table + +@subsection Examples + +@itemize +@item +Extract closed captions as text subtitle stream and overlay it onto the video in cc style (black bar background): +@example +ffmpeg -i "https://streams.videolan.org/streams/ts/CC/NewsStream-608-ac3.ts" -filter_complex "[0:v:0]splitcc=use_cc_styles=1[vid1][sub1];[vid1][sub1]overlaytextsubs" output.mkv +@end example + +@item +A nicer variant, using realtime output from cc_dec and rendering it with the render_latest_only parameter from overlaytextsubs to avoid ghosting by timely overlap. +@example +ffmpeg -i "https://streams.videolan.org/streams/ts/CC/NewsStream-608-ac3.ts" -filter_complex "[0:v:0]splitcc=real_time=1:real_time_latency_msec=200[vid1][sub1];[vid1][sub1]overlaytextsubs=render_latest_only=1" output.mkv +@end example +@end itemize + + @section textsub2video Converts text subtitles to video frames. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index d69fa61c91..9477b56649 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -559,6 +559,7 @@ OBJS-$(CONFIG_NULLSINK_FILTER) += vsink_nullsink.o OBJS-$(CONFIG_CENSOR_FILTER) += sf_textmod.o OBJS-$(CONFIG_SHOW_SPEAKER_FILTER) += sf_textmod.o OBJS-$(CONFIG_TEXTMOD_FILTER) += sf_textmod.o +OBJS-$(CONFIG_SPLITCC_FILTER) += sf_splitcc.o OBJS-$(CONFIG_STRIPSTYLES_FILTER) += sf_stripstyles.o # multimedia filters diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 32a0ebe71b..65b6bea650 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -548,6 +548,7 @@ extern const AVFilter ff_avf_showwavespic; extern const AVFilter ff_vaf_spectrumsynth; extern const AVFilter ff_sf_censor; extern const AVFilter ff_sf_showspeaker; +extern const AVFilter ff_sf_splitcc; extern const AVFilter ff_sf_stripstyles; extern const AVFilter ff_sf_textmod; extern const AVFilter ff_svf_graphicsub2video; diff --git a/libavfilter/sf_splitcc.c b/libavfilter/sf_splitcc.c new file mode 100644 index 0000000000..3556d084d9 --- /dev/null +++ b/libavfilter/sf_splitcc.c @@ -0,0 +1,378 @@ +/* + * Copyright (c) 2021 softworkz + * + * 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 + */ + +/** + * @file + * subtitle filter for splitting out closed-caption/A53 subtitles from video frame side data + */ + +#include "filters.h" +#include "libavutil/opt.h" +#include "subtitles.h" +#include "libavcodec/avcodec.h" + +static const AVRational ms_tb = {1, 1000}; + +typedef struct SplitCaptionsContext { + const AVClass *class; + enum AVSubtitleType format; + AVCodecContext *cc_dec; + int eof; + AVFrame *next_sub_frame; + AVFrame *empty_sub_frame; + int new_frame; + int64_t next_repetition_pts; + AVBufferRef *subtitle_header; + int use_cc_styles; + int real_time; + int real_time_latency_msec; + int data_field; + int scatter_realtime_output; +} SplitCaptionsContext; + +static int init(AVFilterContext *ctx) +{ + SplitCaptionsContext *s = ctx->priv; + AVDictionary *options = NULL; + + int ret; + const AVCodec *codec = avcodec_find_decoder(AV_CODEC_ID_EIA_608); + if (!codec) { + av_log(ctx, AV_LOG_ERROR, "failed to find EIA-608/708 decoder\n"); + return AVERROR_DECODER_NOT_FOUND; + } + + if (!((s->cc_dec = avcodec_alloc_context3(codec)))) { + av_log(ctx, AV_LOG_ERROR, "failed to allocate EIA-608/708 decoder\n"); + return AVERROR(ENOMEM); + } + + av_dict_set_int(&options, "real_time", s->real_time, 0); + av_dict_set_int(&options, "real_time_latency_msec", s->real_time_latency_msec, 0); + av_dict_set_int(&options, "data_field", s->data_field, 0); + + if ((ret = avcodec_open2(s->cc_dec, codec, &options)) < 0) { + av_log(ctx, AV_LOG_ERROR, "failed to open EIA-608/708 decoder: %i\n", ret); + return ret; + } + + if (s->use_cc_styles && s->cc_dec->subtitle_header && s->cc_dec->subtitle_header[0] != 0) { + char* subtitle_header = av_strdup((char *)s->cc_dec->subtitle_header); + if (!subtitle_header) + return AVERROR(ENOMEM); + s->subtitle_header = av_buffer_create((uint8_t *)subtitle_header, strlen(subtitle_header) + 1, NULL, NULL, 0); + if (!s->subtitle_header) { + av_free(subtitle_header); + return AVERROR(ENOMEM); + } + } + + return 0; +} + +static void uninit(AVFilterContext *ctx) +{ + SplitCaptionsContext *s = ctx->priv; + av_frame_free(&s->next_sub_frame); + av_frame_free(&s->empty_sub_frame); + av_buffer_unref(&s->subtitle_header); +} + +static int config_input(AVFilterLink *link) +{ + const SplitCaptionsContext *context = link->dst->priv; + + if (context->cc_dec) + context->cc_dec->pkt_timebase = link->time_base; + + return 0; +} + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterFormats *formats; + AVFilterLink *inlink0 = ctx->inputs[0]; + AVFilterLink *outlink0 = ctx->outputs[0]; + AVFilterLink *outlink1 = ctx->outputs[1]; + static const enum AVSubtitleType subtitle_fmts[] = { AV_SUBTITLE_FMT_ASS, AV_SUBTITLE_FMT_NB }; + int ret; + + /* set input0 video formats */ + formats = ff_all_formats(AVMEDIA_TYPE_VIDEO); + if ((ret = ff_formats_ref(formats, &inlink0->outcfg.formats)) < 0) + return ret; + + /* set output0 video formats */ + if ((ret = ff_formats_ref(formats, &outlink0->incfg.formats)) < 0) + return ret; + + /* set output1 subtitle formats */ + formats = ff_make_format_list(subtitle_fmts); + if ((ret = ff_formats_ref(formats, &outlink1->incfg.formats)) < 0) + return ret; + + return 0; +} + +static int config_video_output(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + const AVFilterLink *inlink = outlink->src->inputs[0]; + + outlink->w = ctx->inputs[0]->w; + outlink->h = ctx->inputs[0]->h; + outlink->frame_rate = ctx->inputs[0]->frame_rate; + outlink->time_base = ctx->inputs[0]->time_base; + outlink->sample_aspect_ratio = ctx->inputs[0]->sample_aspect_ratio; + + if (inlink->hw_frames_ctx) + outlink->hw_frames_ctx = av_buffer_ref(inlink->hw_frames_ctx); + + return 0; +} + +static int config_sub_output(AVFilterLink *outlink) +{ + const AVFilterLink *inlink = outlink->src->inputs[0]; + + outlink->time_base = inlink->time_base; + outlink->format = AV_SUBTITLE_FMT_ASS; + outlink->frame_rate = (AVRational){5, 1}; + + return 0; +} + +static int request_sub_frame(AVFilterLink *outlink) +{ + SplitCaptionsContext *s = outlink->src->priv; + int status; + int64_t pts; + + if (!s->empty_sub_frame) { + s->empty_sub_frame = ff_get_subtitles_buffer(outlink, outlink->format); + if (!s->empty_sub_frame) + return AVERROR(ENOMEM); + } + + if (!s->eof && ff_inlink_acknowledge_status(outlink->src->inputs[0], &status, &pts)) { + if (status == AVERROR_EOF) + s->eof = 1; + } + + if (s->eof) + return AVERROR_EOF; + + if (s->next_sub_frame) { + + AVFrame *out = NULL; + s->next_sub_frame->pts++; + + if (s->new_frame) + out = av_frame_clone(s->next_sub_frame); + else if (s->empty_sub_frame) { + s->empty_sub_frame->pts = s->next_sub_frame->pts; + out = av_frame_clone(s->empty_sub_frame); + av_frame_copy_props(out, s->next_sub_frame); + } + + if (!out) + return AVERROR(ENOMEM); + + out->subtitle_pts = av_rescale_q(s->next_sub_frame->pts, outlink->time_base, AV_TIME_BASE_Q); + s->new_frame = 0; + + return ff_filter_frame(outlink, out); + } + + return 0; +} + +static int decode(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *pkt) +{ + int ret; + + *got_frame = 0; + + if (pkt) { + ret = avcodec_send_packet(avctx, pkt); + // In particular, we don't expect AVERROR(EAGAIN), because we read all + // decoded frames with avcodec_receive_frame() until done. + if (ret < 0 && ret != AVERROR_EOF) + return ret; + } + + ret = avcodec_receive_frame(avctx, frame); + if (ret < 0 && ret != AVERROR(EAGAIN)) + return ret; + if (ret >= 0) + *got_frame = 1; + + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *frame) +{ + AVFrameSideData *sd; + SplitCaptionsContext *s = inlink->dst->priv; + AVFilterLink *outlink0 = inlink->dst->outputs[0]; + AVFilterLink *outlink1 = inlink->dst->outputs[1]; + AVPacket *pkt = NULL; + AVFrame *sub_out = NULL; + + int ret; + + outlink0->format = inlink->format; + + sd = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC); + + if (sd) { + int got_output = 0; + + pkt = av_packet_alloc(); + pkt->buf = av_buffer_ref(sd->buf); + if (!pkt->buf) { + ret = AVERROR(ENOMEM); + goto fail; + } + + pkt->data = sd->data; + pkt->size = (int)sd->size; + pkt->pts = frame->pts; + + sub_out = ff_get_subtitles_buffer(outlink1, AV_SUBTITLE_FMT_ASS); + if (!sub_out) { + ret = AVERROR(ENOMEM); + goto fail; + } + + if ((ret = av_buffer_replace(&sub_out->subtitle_header, s->subtitle_header)) < 0) + goto fail; + + ret = decode(s->cc_dec, sub_out, &got_output, pkt); + + if (ret < 0) + goto fail; + + if (got_output) { + sub_out->pts = frame->pts; + av_frame_free(&s->next_sub_frame); + s->next_sub_frame = sub_out; + sub_out = NULL; + s->new_frame = 1; + s->next_sub_frame->pts = frame->pts; + + if ((ret = av_buffer_replace(&s->next_sub_frame->subtitle_header, s->subtitle_header)) < 0) + goto fail; + + if (s->real_time && s->scatter_realtime_output) { + if (s->next_repetition_pts) + s->next_sub_frame->pts = s->next_repetition_pts; + + s->next_sub_frame->subtitle_end_time = s->real_time_latency_msec; + s->next_repetition_pts = s->next_sub_frame->pts + av_rescale_q(s->real_time_latency_msec, ms_tb, inlink->time_base); + } + + ret = request_sub_frame(outlink1); + if (ret < 0) + goto fail; + } + } + + if (s->real_time && s->scatter_realtime_output && !s->new_frame && s->next_repetition_pts > 0 && frame->pts > s->next_repetition_pts) { + s->new_frame = 1; + s->next_sub_frame->pts = s->next_repetition_pts; + s->next_repetition_pts = s->next_sub_frame->pts + av_rescale_q(s->real_time_latency_msec, ms_tb, inlink->time_base); + } + + if (!s->next_sub_frame) { + s->next_sub_frame = ff_get_subtitles_buffer(outlink1, outlink1->format); + if (!s->next_sub_frame) { + ret = AVERROR(ENOMEM); + goto fail; + } + + s->next_sub_frame->subtitle_end_time = 100; + s->next_sub_frame->pts = frame->pts; + s->new_frame = 1; + + if ((ret = av_buffer_replace(&s->next_sub_frame->subtitle_header, s->subtitle_header)) < 0) + goto fail; + } + + ret = ff_filter_frame(outlink0, frame); + +fail: + av_packet_free(&pkt); + av_frame_free(&sub_out); + return ret; +} + +#define OFFSET(x) offsetof(SplitCaptionsContext, x) +#define FLAGS (AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_FILTERING_PARAM) + +static const AVOption split_cc_options[] = { + { "use_cc_styles", "Emit closed caption style header", OFFSET(use_cc_styles), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS, NULL }, + { "real_time", "emit subtitle events as they are decoded for real-time display", OFFSET(real_time), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, + { "real_time_latency_msec", "minimum elapsed time between emitting real-time subtitle events", OFFSET(real_time_latency_msec), AV_OPT_TYPE_INT, { .i64 = 200 }, 0, 500, FLAGS }, + { "scatter_realtime_output", "scatter output events to a duration of real_time_latency_msec", OFFSET(scatter_realtime_output), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, + { "data_field", "select data field", OFFSET(data_field), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, FLAGS, "data_field" }, + { "auto", "pick first one that appears", 0, AV_OPT_TYPE_CONST, { .i64 =-1 }, 0, 0, FLAGS, "data_field" }, + { "first", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "data_field" }, + { "second", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "data_field" }, + { NULL }, +}; + +AVFILTER_DEFINE_CLASS(split_cc); + +static const AVFilterPad inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + .config_props = config_input, + }, +}; + +static const AVFilterPad outputs[] = { + { + .name = "video_passthrough", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_video_output, + }, + { + .name = "subtitles", + .type = AVMEDIA_TYPE_SUBTITLE, + .request_frame = request_sub_frame, + .config_props = config_sub_output, + }, +}; + +const AVFilter ff_sf_splitcc = { + .name = "splitcc", + .description = NULL_IF_CONFIG_SMALL("Extract closed-caption (A53) data from video as subtitle stream."), + .init = init, + .uninit = uninit, + .priv_size = sizeof(SplitCaptionsContext), + .priv_class = &split_cc_class, + .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE, + FILTER_INPUTS(inputs), + FILTER_OUTPUTS(outputs), + FILTER_QUERY_FUNC(query_formats), +};