[FFmpeg-devel] [PATCH 2/3] Metadata muxer
Anton Khirnov
anton
Sun Dec 26 20:30:42 CET 2010
Dumps all metadata to a text file for easy manual editing.
---
Makefile | 2 +-
doc/ffmpeg.texi | 1 +
doc/general.texi | 2 +
doc/metadata.texi | 68 ++++++++++++++++++++++++++++++
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/meta.h | 29 +++++++++++++
libavformat/metaenc.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++
8 files changed, 205 insertions(+), 1 deletions(-)
create mode 100644 doc/metadata.texi
create mode 100644 libavformat/meta.h
create mode 100644 libavformat/metaenc.c
diff --git a/Makefile b/Makefile
index 65b5c9a..4242eb1 100644
--- a/Makefile
+++ b/Makefile
@@ -116,7 +116,7 @@ documentation: $(addprefix doc/, developer.html faq.html general.html libavfilte
$(HTMLPAGES) $(PODPAGES): doc/fftools-common-opts.texi
-doc/ffmpeg.pod doc/ffmpeg.html: doc/bitstream_filters.texi doc/eval.texi doc/indevs.texi doc/filters.texi doc/outdevs.texi doc/protocols.texi
+doc/ffmpeg.pod doc/ffmpeg.html: doc/bitstream_filters.texi doc/eval.texi doc/indevs.texi doc/filters.texi doc/outdevs.texi doc/protocols.texi doc/metadata.texi
doc/ffplay.pod doc/ffplay.html: doc/eval.texi doc/indevs.texi doc/filters.texi doc/outdevs.texi doc/protocols.texi
doc/ffprobe.pod doc/ffprobe.html: doc/indevs.texi doc/protocols.texi
diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 397c3b4..d73ae46 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -949,6 +949,7 @@ file to which you want to add them.
@include protocols.texi
@include bitstream_filters.texi
@include filters.texi
+ at include metadata.texi
@ignore
diff --git a/doc/general.texi b/doc/general.texi
index 9eb8c86..410b8fa 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -118,6 +118,8 @@ library:
@tab VR native stream format, used by Leitch/Harris' video servers.
@item Matroska @tab X @tab X
@item Matroska audio @tab X @tab
+ at item FFmpeg metadata @tab X @tab
+ @tab Metadata in text format.
@item MAXIS XA @tab @tab X
@tab Used in Sim City 3000; file extension .xa.
@item MD Studio @tab @tab X
diff --git a/doc/metadata.texi b/doc/metadata.texi
new file mode 100644
index 0000000..2a28575
--- /dev/null
+++ b/doc/metadata.texi
@@ -0,0 +1,68 @@
+ at chapter Metadata
+ at c man begin METADATA
+
+FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
+INI-like text file and then load it back using the metadata muxer/demuxer.
+
+The file format is as follows:
+ at enumerate
+
+ at item
+A file consists of a header and a number of metadata tags divided into sections,
+each on its own line.
+
+ at item
+The header is a ';FFMETADATA' string, followed by a version number (now 1).
+
+ at item
+Metadata tags are of the form 'key=value'
+
+ at item
+Immediately after header follows global metadata
+
+ at item
+After global metadata there may be sections with per-stream/per-chapter
+metadata.
+
+ at item
+A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
+brackets ('[', ']') and ends with next section or end of file.
+
+ at item
+At the beginning of a chapter section there may be an optional timebase to be
+used for start/end values. It must be in form 'TIMEBASE=num/den', where num and
+den are integers. If the timebase is missing then start/end times are assumed to
+be in milliseconds.
+Next a chapter section must contain chapter start and end times in form
+'START=num', 'END=num', where num is a positive integer.
+
+ at item
+Empty lines and lines starting with ';' or '#' are ignored.
+
+ at item
+Metadata keys or values containing special characters ('=', ';', '#', '\' and a
+newline) must be escaped with a backslash '\'.
+
+ at item
+Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
+the tag (in the example above key is 'foo ', value is ' bar').
+ at end enumerate
+
+A ffmetadata file might look like this:
+ at example
+;FFMETADATA1
+title=bike\\shed
+;this is a comment
+artist=FFmpeg troll team
+
+[CHAPTER]
+TIMEBASE=1/1000
+START=0
+#chapter ends at 0:01:00
+END=60000
+title=chapter \#1
+[STREAM]
+title=multi\
+line
+ at end example
+ at c man end METADATA
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 030df2b6..2d370b2 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -70,6 +70,7 @@ OBJS-$(CONFIG_EAC3_DEMUXER) += ac3dec.o rawdec.o
OBJS-$(CONFIG_EAC3_MUXER) += rawenc.o
OBJS-$(CONFIG_FFM_DEMUXER) += ffmdec.o
OBJS-$(CONFIG_FFM_MUXER) += ffmenc.o
+OBJS-$(CONFIG_FFMETADATA_MUXER) += metaenc.o
OBJS-$(CONFIG_FILMSTRIP_DEMUXER) += filmstripdec.o
OBJS-$(CONFIG_FILMSTRIP_MUXER) += filmstripenc.o
OBJS-$(CONFIG_FLAC_DEMUXER) += flacdec.o rawdec.o \
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 9662e41..6c7ba30 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -85,6 +85,7 @@ void av_register_all(void)
REGISTER_DEMUXER (EA_CDATA, ea_cdata);
REGISTER_MUXDEMUX (EAC3, eac3);
REGISTER_MUXDEMUX (FFM, ffm);
+ REGISTER_MUXER (FFMETADATA, ffmetadata);
REGISTER_MUXDEMUX (FILMSTRIP, filmstrip);
REGISTER_MUXDEMUX (FLAC, flac);
REGISTER_DEMUXER (FLIC, flic);
diff --git a/libavformat/meta.h b/libavformat/meta.h
new file mode 100644
index 0000000..f96dbb2
--- /dev/null
+++ b/libavformat/meta.h
@@ -0,0 +1,29 @@
+/*
+ * Common data for metadata muxer/demuxer
+ * Copyright (c) 2010 Anton Khirnov
+ *
+ * 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_META_H
+#define AVFORMAT_META_H
+
+#define ID_STRING ";FFMETADATA"
+#define ID_CHAPTER "[CHAPTER]"
+#define ID_STREAM "[STREAM]"
+
+#endif /* AVFORMAT_META_H */
diff --git a/libavformat/metaenc.c b/libavformat/metaenc.c
new file mode 100644
index 0000000..7df5850
--- /dev/null
+++ b/libavformat/metaenc.c
@@ -0,0 +1,102 @@
+/*
+ * Metadata muxer
+ * Copyright (c) 2010 Anton Khirnov
+ *
+ * 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 "avformat.h"
+#include "meta.h"
+
+
+static void write_escape_str(ByteIOContext *s, const uint8_t *str)
+{
+ const uint8_t *p = str;
+
+ while (*p) {
+ if (*p == '#' || *p == ';' || *p == '=' || *p == '\\' || *p == '\n')
+ put_byte(s, '\\');
+ put_byte(s, *p);
+ p++;
+ }
+}
+
+static void write_tags(ByteIOContext *s, AVMetadata *m)
+{
+ AVMetadataTag *t = NULL;
+ while ((t = av_metadata_get(m, "", t, AV_METADATA_IGNORE_SUFFIX))) {
+ write_escape_str(s, t->key);
+ put_byte(s, '=');
+ write_escape_str(s, t->value);
+ put_byte(s, '\n');
+ }
+}
+
+static int write_header(AVFormatContext *s)
+{
+ put_tag(s->pb, ID_STRING);
+ put_byte(s->pb, '1'); // version
+ put_byte(s->pb, '\n');
+ put_flush_packet(s->pb);
+ return 0;
+}
+
+static int write_trailer(AVFormatContext *s)
+{
+ int i;
+
+ write_tags(s->pb, s->metadata);
+
+ for (i = 0; i < s->nb_streams; i++) {
+ put_tag(s->pb, ID_STREAM);
+ put_byte(s->pb, '\n');
+ write_tags(s->pb, s->streams[i]->metadata);
+ }
+
+ for (i = 0; i < s->nb_chapters; i++) {
+ AVChapter *ch = s->chapters[i];
+ put_tag(s->pb, ID_CHAPTER);
+ put_byte(s->pb, '\n');
+ url_fprintf(s->pb, "TIMEBASE=%d/%d\n", ch->time_base.num, ch->time_base.den);
+ url_fprintf(s->pb, "START=%lld\n", ch->start);
+ url_fprintf(s->pb, "END=%lld\n", ch->end);
+ write_tags(s->pb, ch->metadata);
+ }
+
+ put_flush_packet(s->pb);
+
+ return 0;
+}
+
+static int write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ return 0;
+}
+
+AVOutputFormat ffmetadata_muxer = {
+ "ffmetadata",
+ NULL_IF_CONFIG_SMALL("FFmpeg metadata in text format"),
+ NULL,
+ "ffmeta",
+ 0,
+ CODEC_ID_NONE,
+ CODEC_ID_NONE,
+ write_header,
+ write_packet,
+ write_trailer,
+ .flags = AVFMT_NOTIMESTAMPS | AVFMT_NOSTREAMS,
+};
--
1.7.2.3
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