diff --git a/Changelog b/Changelog index a84d8db09b..fcc9f7cfba 100644 --- a/Changelog +++ b/Changelog @@ -2,6 +2,7 @@ Entries are sorted chronologically from oldest to youngest within each release, releases are sorted from youngest to oldest. version : +- Raw Captions with Time (RCWT) closed caption demuxer version 7.0: diff --git a/doc/demuxers.texi b/doc/demuxers.texi index b70f3a38d7..04293c4813 100644 --- a/doc/demuxers.texi +++ b/doc/demuxers.texi @@ -1038,6 +1038,36 @@ the command: ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw @end example +@anchor{rcwtdec} +@section rcwt + +RCWT (Raw Captions With Time) is a format native to ccextractor, a commonly +used open source tool for processing 608/708 Closed Captions (CC) sources. +For more information on the format, see @ref{rcwtenc,,,ffmpeg-formats}. + +This demuxer implements the specification as of March 2024, which has +been stable and unchanged since April 2014. + +@subsection Examples + +@itemize +@item +Render CC to ASS using the built-in decoder: +@example +ffmpeg -i CC.rcwt.bin CC.ass +@end example +Note that if your output appears to be empty, you may have to manually +set the decoder's @option{data_field} option to pick the desired CC substream. + +@item +Convert an RCWT backup to Scenarist (SCC) format: +@example +ffmpeg -i CC.rcwt.bin -c:s copy CC.scc +@end example +Note that the SCC format does not support all of the possible CC extensions +that can be stored in RCWT (such as EIA-708). +@end itemize + @section sbg SBaGen script demuxer. diff --git a/libavformat/Makefile b/libavformat/Makefile index 44aa485029..5d77cba7f1 100644 --- a/libavformat/Makefile +++ b/libavformat/Makefile @@ -493,6 +493,7 @@ OBJS-$(CONFIG_QOA_DEMUXER) += qoadec.o OBJS-$(CONFIG_R3D_DEMUXER) += r3d.o OBJS-$(CONFIG_RAWVIDEO_DEMUXER) += rawvideodec.o OBJS-$(CONFIG_RAWVIDEO_MUXER) += rawenc.o +OBJS-$(CONFIG_RCWT_DEMUXER) += rcwtdec.o subtitles.o OBJS-$(CONFIG_RCWT_MUXER) += rcwtenc.o subtitles.o OBJS-$(CONFIG_REALTEXT_DEMUXER) += realtextdec.o subtitles.o OBJS-$(CONFIG_REDSPARK_DEMUXER) += redspark.o diff --git a/libavformat/allformats.c b/libavformat/allformats.c index 9df42bb87a..ae925dcf60 100644 --- a/libavformat/allformats.c +++ b/libavformat/allformats.c @@ -391,6 +391,7 @@ extern const FFInputFormat ff_qoa_demuxer; extern const FFInputFormat ff_r3d_demuxer; extern const FFInputFormat ff_rawvideo_demuxer; extern const FFOutputFormat ff_rawvideo_muxer; +extern const FFInputFormat ff_rcwt_demuxer; extern const FFOutputFormat ff_rcwt_muxer; extern const FFInputFormat ff_realtext_demuxer; extern const FFInputFormat ff_redspark_demuxer; diff --git a/libavformat/rcwtdec.c b/libavformat/rcwtdec.c new file mode 100644 index 0000000000..f6a007cbdb --- /dev/null +++ b/libavformat/rcwtdec.c @@ -0,0 +1,122 @@ +/* + * RCWT (Raw Captions With Time) demuxer + * + * 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 + */ + +/* + * RCWT (Raw Captions With Time) is a format native to ccextractor, a commonly + * used open source tool for processing 608/708 Closed Captions (CC) sources. + * + * This demuxer implements the specification as of March 2024, which has + * been stable and unchanged since April 2014. + * + * A free specification of RCWT can be found here: + * @url{https://github.com/CCExtractor/ccextractor/blob/master/docs/BINARY_FILE_FORMAT.TXT} + */ + +#include "avformat.h" +#include "demux.h" +#include "internal.h" +#include "subtitles.h" +#include "libavutil/intreadwrite.h" + +#define RCWT_HEADER_SIZE 11 + +typedef struct RCWTContext { + FFDemuxSubtitlesQueue q; +} RCWTContext; + +static int rcwt_read_header(AVFormatContext *avf) +{ + RCWTContext *rcwt = avf->priv_data; + + AVStream *st; + uint8_t header[RCWT_HEADER_SIZE]; + int ret; + + /* read header */ + ret = ffio_read_size(avf->pb, header, RCWT_HEADER_SIZE); + if (ret < 0) + return ret; + + if (AV_RB16(header + 6) != 0x0001) { + av_log(avf, AV_LOG_ERROR, "RCWT format version is not compatible " + "(only version 0.001 is known)\n"); + return AVERROR_INVALIDDATA; + } + + av_log(avf, AV_LOG_DEBUG, "RCWT writer application: %02X version: %02x\n", + header[3], header[5]); + + /* setup stream */ + st = avformat_new_stream(avf, NULL); + if (!st) + return AVERROR(ENOMEM); + + st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE; + st->codecpar->codec_id = AV_CODEC_ID_EIA_608; + + avpriv_set_pts_info(st, 64, 1, 1000); + + /* demux */ + while (!avio_feof(avf->pb)) { + AVPacket *sub; + int64_t cluster_pos = avio_tell(avf->pb); + int64_t cluster_pts = avio_rl64(avf->pb); + int cluster_nb_blocks = avio_rl16(avf->pb); + + if (cluster_nb_blocks == 0) + continue; + + sub = ff_subtitles_queue_insert(&rcwt->q, NULL, 0, 0); + if (!sub) + return AVERROR(ENOMEM); + + ret = av_get_packet(avf->pb, sub, cluster_nb_blocks * 3); + if (ret < 0) + return ret; + + sub->pos = cluster_pos; + sub->pts = cluster_pts; + } + + ff_subtitles_queue_finalize(avf, &rcwt->q); + + return 0; +} + +static int rcwt_probe(const AVProbeData *p) +{ + return p->buf_size > RCWT_HEADER_SIZE && + AV_RB16(p->buf) == 0xCCCC && + AV_RB8(p->buf + 2) == 0xED && + AV_RB16(p->buf + 6) == 0x0001 ? 50 : 0; +} + +const FFInputFormat ff_rcwt_demuxer = { + .p.name = "rcwt", + .p.long_name = NULL_IF_CONFIG_SMALL("RCWT (Raw Captions With Time)"), + .p.flags = AVFMT_TS_DISCONT, + .priv_data_size = sizeof(RCWTContext), + .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP, + .read_probe = rcwt_probe, + .read_header = rcwt_read_header, + .read_packet = ff_subtitles_read_packet, + .read_seek2 = ff_subtitles_read_seek, + .read_close = ff_subtitles_read_close +};