avformat/movenc: add support for TTML muxing

Includes basic support for both the ISMV ('dfxp') and MP4 ('stpp')
methods. This initial version also foregoes fragmentation support
in case the built-in sample squashing is to be utilized, as this
eases the initial review.

Additionally, add basic tests for both muxing modes in MP4.

Signed-off-by: Jan Ekström <jan.ekstrom@24i.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/libavformat/movenc_ttml.h b/libavformat/movenc_ttml.h
new file mode 100644
index 0000000000..c71ecd0997
--- /dev/null
+++ b/libavformat/movenc_ttml.h
@@ -0,0 +1,31 @@
+/*
+ * MP4, ISMV Muxer TTML helpers
+ * Copyright (c) 2021 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
+ */
+
+#ifndef AVFORMAT_MOVENC_TTML_H
+#define AVFORMAT_MOVENC_TTML_H
+
+#include "avformat.h"
+#include "movenc.h"
+
+int ff_mov_generate_squashed_ttml_packet(AVFormatContext *s,
+                                         MOVTrack *track, AVPacket *pkt);
+
+#endif /* AVFORMAT_MOVENC_TTML_H */