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authorJan Ekström <jan.ekstrom@24i.com>2021-03-04 19:09:50 +0200
committerJan Ekström <jeebjp@gmail.com>2021-03-05 19:45:00 +0200
commit64af14555be2c9e522109e55160e0cb3f65c4690 (patch)
tree17dbdb82f0aea09ae79ce588ee07d6843aac3a65 /libavformat
parent18713d22a2001321f9917fa4c7735f62563ec0a1 (diff)
avformat: add TTML muxer
Enables writing TTML documents or encoded TTML paragraphs as such documents. Additionally, a test for the combined TTML encoder and muxer has been added to validate that the components still work. Signed-off-by: Jan Ekström <jan.ekstrom@24i.com>
Diffstat (limited to 'libavformat')
-rw-r--r--libavformat/Makefile1
-rw-r--r--libavformat/allformats.c1
-rw-r--r--libavformat/ttmlenc.c174
-rw-r--r--libavformat/version.h2
4 files changed, 177 insertions, 1 deletions
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 48b91ea4d0..0504f47f88 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -546,6 +546,7 @@ OBJS-$(CONFIG_TRUEHD_DEMUXER) += rawdec.o mlpdec.o
OBJS-$(CONFIG_TRUEHD_MUXER) += rawenc.o
OBJS-$(CONFIG_TTA_DEMUXER) += tta.o apetag.o img2.o
OBJS-$(CONFIG_TTA_MUXER) += ttaenc.o apetag.o img2.o
+OBJS-$(CONFIG_TTML_MUXER) += ttmlenc.o
OBJS-$(CONFIG_TTY_DEMUXER) += tty.o sauce.o
OBJS-$(CONFIG_TY_DEMUXER) += ty.o
OBJS-$(CONFIG_TXD_DEMUXER) += txd.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index ade247640c..a38fd1f583 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -445,6 +445,7 @@ extern AVInputFormat ff_truehd_demuxer;
extern AVOutputFormat ff_truehd_muxer;
extern AVInputFormat ff_tta_demuxer;
extern AVOutputFormat ff_tta_muxer;
+extern AVOutputFormat ff_ttml_muxer;
extern AVInputFormat ff_txd_demuxer;
extern AVInputFormat ff_tty_demuxer;
extern AVInputFormat ff_ty_demuxer;
diff --git a/libavformat/ttmlenc.c b/libavformat/ttmlenc.c
new file mode 100644
index 0000000000..940f8bbd4e
--- /dev/null
+++ b/libavformat/ttmlenc.c
@@ -0,0 +1,174 @@
+/*
+ * TTML subtitle muxer
+ * Copyright (c) 2020 24i
+ *
+ * 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
+ * TTML subtitle muxer
+ * @see https://www.w3.org/TR/ttml1/
+ * @see https://www.w3.org/TR/ttml2/
+ * @see https://www.w3.org/TR/ttml-imsc/rec
+ */
+
+#include "avformat.h"
+#include "internal.h"
+#include "libavcodec/ttmlenc.h"
+#include "libavutil/internal.h"
+
+enum TTMLPacketType {
+ PACKET_TYPE_PARAGRAPH,
+ PACKET_TYPE_DOCUMENT,
+};
+
+typedef struct TTMLMuxContext {
+ enum TTMLPacketType input_type;
+ unsigned int document_written;
+} TTMLMuxContext;
+
+static const char ttml_header_text[] =
+"<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
+"<tt\n"
+" xmlns=\"http://www.w3.org/ns/ttml\"\n"
+" xmlns:ttm=\"http://www.w3.org/ns/ttml#metadata\"\n"
+" xmlns:tts=\"http://www.w3.org/ns/ttml#styling\"\n"
+" xml:lang=\"%s\">\n"
+" <body>\n"
+" <div>\n";
+
+static const char ttml_footer_text[] =
+" </div>\n"
+" </body>\n"
+"</tt>\n";
+
+static void ttml_write_time(AVIOContext *pb, const char tag[],
+ int64_t millisec)
+{
+ int64_t sec, min, hour;
+ sec = millisec / 1000;
+ millisec -= 1000 * sec;
+ min = sec / 60;
+ sec -= 60 * min;
+ hour = min / 60;
+ min -= 60 * hour;
+
+ avio_printf(pb, "%s=\"%02"PRId64":%02"PRId64":%02"PRId64".%03"PRId64"\"",
+ tag, hour, min, sec, millisec);
+}
+
+static int ttml_write_header(AVFormatContext *ctx)
+{
+ TTMLMuxContext *ttml_ctx = ctx->priv_data;
+ ttml_ctx->document_written = 0;
+
+ if (ctx->nb_streams != 1 ||
+ ctx->streams[0]->codecpar->codec_id != AV_CODEC_ID_TTML) {
+ av_log(ctx, AV_LOG_ERROR, "Exactly one TTML stream is required!\n");
+ return AVERROR(EINVAL);
+ }
+
+ {
+ AVStream *st = ctx->streams[0];
+ AVIOContext *pb = ctx->pb;
+
+ AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL,
+ 0);
+ const char *printed_lang = (lang && lang->value) ? lang->value : "";
+
+ // Not perfect, but decide whether the packet is a document or not
+ // by the existence of the lavc ttmlenc extradata.
+ ttml_ctx->input_type = (st->codecpar->extradata &&
+ st->codecpar->extradata_size >= TTMLENC_EXTRADATA_SIGNATURE_SIZE &&
+ !memcmp(st->codecpar->extradata,
+ TTMLENC_EXTRADATA_SIGNATURE,
+ TTMLENC_EXTRADATA_SIGNATURE_SIZE)) ?
+ PACKET_TYPE_PARAGRAPH :
+ PACKET_TYPE_DOCUMENT;
+
+ avpriv_set_pts_info(st, 64, 1, 1000);
+
+ if (ttml_ctx->input_type == PACKET_TYPE_PARAGRAPH)
+ avio_printf(pb, ttml_header_text, printed_lang);
+ }
+
+ return 0;
+}
+
+static int ttml_write_packet(AVFormatContext *ctx, AVPacket *pkt)
+{
+ TTMLMuxContext *ttml_ctx = ctx->priv_data;
+ AVIOContext *pb = ctx->pb;
+
+ switch (ttml_ctx->input_type) {
+ case PACKET_TYPE_PARAGRAPH:
+ // write out a paragraph element with the given contents.
+ avio_printf(pb, " <p\n");
+ ttml_write_time(pb, " begin", pkt->pts);
+ avio_w8(pb, '\n');
+ ttml_write_time(pb, " end", pkt->pts + pkt->duration);
+ avio_printf(pb, ">");
+ avio_write(pb, pkt->data, pkt->size);
+ avio_printf(pb, "</p>\n");
+ break;
+ case PACKET_TYPE_DOCUMENT:
+ // dump the given document out as-is.
+ if (ttml_ctx->document_written) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Attempting to write multiple TTML documents into a "
+ "single document! The XML specification forbids this "
+ "as there has to be a single root tag.\n");
+ return AVERROR(EINVAL);
+ }
+ avio_write(pb, pkt->data, pkt->size);
+ ttml_ctx->document_written = 1;
+ break;
+ default:
+ av_log(ctx, AV_LOG_ERROR,
+ "Internal error: invalid TTML input packet type: %d!\n",
+ ttml_ctx->input_type);
+ return AVERROR_BUG;
+ }
+
+ return 0;
+}
+
+static int ttml_write_trailer(AVFormatContext *ctx)
+{
+ TTMLMuxContext *ttml_ctx = ctx->priv_data;
+ AVIOContext *pb = ctx->pb;
+
+ if (ttml_ctx->input_type == PACKET_TYPE_PARAGRAPH)
+ avio_printf(pb, ttml_footer_text);
+
+ return 0;
+}
+
+AVOutputFormat ff_ttml_muxer = {
+ .name = "ttml",
+ .long_name = NULL_IF_CONFIG_SMALL("TTML subtitle"),
+ .extensions = "ttml",
+ .mime_type = "text/ttml",
+ .priv_data_size = sizeof(TTMLMuxContext),
+ .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
+ AVFMT_TS_NONSTRICT,
+ .subtitle_codec = AV_CODEC_ID_TTML,
+ .write_header = ttml_write_header,
+ .write_packet = ttml_write_packet,
+ .write_trailer = ttml_write_trailer,
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index 3fae3d9645..a05676d979 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -32,7 +32,7 @@
// Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
// Also please add any ticket numbers that you believe might be affected here
#define LIBAVFORMAT_VERSION_MAJOR 58
-#define LIBAVFORMAT_VERSION_MINOR 70
+#define LIBAVFORMAT_VERSION_MINOR 71
#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-09 19:16:25 +0000