[FFmpeg-devel] [PATCH] lavf: add tee pseudo-muxer.
Nicolas George
nicolas.george at normalesup.org
Wed Nov 7 21:45:35 CET 2012
Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
Changelog | 1 +
doc/muxers.texi | 35 ++++++
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/tee.c | 271 ++++++++++++++++++++++++++++++++++++++++++++++
libavformat/version.h | 2 +-
6 files changed, 310 insertions(+), 1 deletion(-)
create mode 100644 libavformat/tee.c
diff --git a/Changelog b/Changelog
index b6bff7b..e1c92e1 100644
--- a/Changelog
+++ b/Changelog
@@ -21,6 +21,7 @@ version <next>:
- metadata (info chunk) support in CAF muxer
- field filter ported from libmpcodecs
- AVR demuxer
+- tee muxer
version 1.0:
diff --git a/doc/muxers.texi b/doc/muxers.texi
index 34eed0f..fc6de0a 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -652,4 +652,39 @@ ffmpeg -i input.mp3 -i cover.png -c copy -metadata:s:v title="Album cover"
-metadata:s:v comment="Cover (Front)" out.mp3
@end example
+ at section tee
+
+The tee muxer can be used to write the same data to several files or any
+other kind of muxer. It can be used, for example, to both stream a video to
+the network and save it to disk at the same time.
+
+It is different from specifying several outputs to the @command{ffmpeg}
+command-line tool because the audio and video data will be encoded only once
+with the tee muxer; encoding can be a very expensive process. It is not
+useful when using the libavformat API directly because it is then possible
+to feed the same packets to several muxers directly.
+
+The slave outputs are specified in the file name given to the muxer,
+separated by '|'. If any of the slave name contains the '|' separator,
+leading or trailing spaces or any special character, it must be
+ at ref{quoting_and_escaping, escaped}.
+
+Options can be specified for each slave by prepending them as a list of
+ at var{key}=@var{value} pairs separated by ':', between square brackets. If
+the options values contain a special character or the ':' separator, they
+must be @ref{quoting_and_escaping, escaped}; note that this is a second
+level escaping.
+
+Example: encode something and both archive it in a WebM file and stream it
+as MPEG-TS over UDP:
+
+ at example
+ffmpeg -i ... -c:v libx264 -c:a libvorbis -f tee
+ "archive-20121107.webm|[f=mpegts]udp://10.0.1.255:1234/"
+ at end example
+
+Note: some codecs may need different options depending on the output format;
+the auto-detection of this can not work with the tee muxer. The main example
+is the @option{global_header} flag.
+
@c man end MUXERS
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 60a9235..8a611b3 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -338,6 +338,7 @@ OBJS-$(CONFIG_SUBVIEWER_DEMUXER) += subviewerdec.o
OBJS-$(CONFIG_SWF_DEMUXER) += swfdec.o swf.o
OBJS-$(CONFIG_SWF_MUXER) += swfenc.o swf.o
OBJS-$(CONFIG_TAK_DEMUXER) += takdec.o apetag.o img2.o rawdec.o
+OBJS-$(CONFIG_TEE_MUXER) += tee.o
OBJS-$(CONFIG_THP_DEMUXER) += thp.o
OBJS-$(CONFIG_TIERTEXSEQ_DEMUXER) += tiertexseq.o
OBJS-$(CONFIG_MKVTIMESTAMP_V2_MUXER) += mkvtimestamp_v2.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index ea345e5..4f1a5bc 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -237,6 +237,7 @@ void av_register_all(void)
REGISTER_DEMUXER (SUBVIEWER, subviewer);
REGISTER_MUXDEMUX (SWF, swf);
REGISTER_DEMUXER (TAK, tak);
+ REGISTER_MUXER (TEE, tee);
REGISTER_MUXER (TG2, tg2);
REGISTER_MUXER (TGP, tgp);
REGISTER_DEMUXER (THP, thp);
diff --git a/libavformat/tee.c b/libavformat/tee.c
new file mode 100644
index 0000000..a3d7ef1
--- /dev/null
+++ b/libavformat/tee.c
@@ -0,0 +1,271 @@
+/*
+ * Tee pesudo-muxer
+ * Copyright (c) 2012 Nicolas George
+ *
+ * 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 "libavutil/avutil.h"
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "avformat.h"
+
+#define MAX_SLAVES 16
+
+typedef struct TeeContext {
+ const AVClass *class;
+ unsigned nb_slaves;
+ AVFormatContext *slaves[MAX_SLAVES];
+} TeeContext;
+
+static const char *const slave_delim = "|";
+static const char *const slave_opt_open = "[";
+static const char *const slave_opt_close = "]";
+static const char *const slave_opt_delim = ":]"; /* must have the close too */
+
+static const AVClass tee_muxer_class = {
+ .class_name = "Tee muxer",
+ .item_name = av_default_item_name,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+static int parse_slave_options(void *log, char *slave,
+ AVDictionary **options, char **filename)
+{
+ const char *p;
+ char *key, *val;
+ int ret;
+
+ if (!strspn(slave, slave_opt_open)) {
+ *filename = slave;
+ return 0;
+ }
+ p = slave + 1;
+ if (strspn(p, slave_opt_close)) {
+ *filename = (char *)p + 1;
+ return 0;
+ }
+ while (1) {
+ ret = av_opt_get_key_value(&p, "=", slave_opt_delim, 0, &key, &val);
+ if (ret < 0) {
+ av_log(log, AV_LOG_ERROR, "No option found near \"%s\"\n", p);
+ goto fail;
+ }
+ ret = av_dict_set(options, key, val,
+ AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
+ if (ret < 0)
+ goto fail;
+ if (strspn(p - 1, slave_opt_close))
+ break;
+ }
+ *filename = (char *)p;
+ return 0;
+
+fail:
+ av_dict_free(options);
+ return ret;
+}
+
+static int open_slave(AVFormatContext *avf, char *slave, AVFormatContext **ravf)
+{
+ int i, ret;
+ AVDictionary *options = NULL;
+ AVDictionaryEntry *entry;
+ char *filename;
+ char *format = NULL;
+ AVFormatContext *avf2 = NULL;
+ AVStream *st, *st2;
+
+ if ((ret = parse_slave_options(avf, slave, &options, &filename)) < 0)
+ return ret;
+ if ((entry = av_dict_get(options, "f", NULL, 0))) {
+ format = entry->value;
+ entry->value = NULL; /* prevent it from being freed */
+ av_dict_set(&options, "f", NULL, 0);
+ }
+
+ avformat_alloc_output_context2(&avf2, NULL, format, filename);
+ if (ret < 0)
+ goto fail;
+ av_free(format);
+
+ for (i = 0; i < avf->nb_streams; i++) {
+ st = avf->streams[i];
+ if (!(st2 = avformat_new_stream(avf2, NULL))) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ st2->id = st->id;
+ st2->r_frame_rate = st->r_frame_rate;
+ st2->time_base = st->time_base;
+ st2->start_time = st->start_time;
+ st2->duration = st->duration;
+ st2->nb_frames = st->nb_frames;
+ st2->disposition = st->disposition;
+ st2->sample_aspect_ratio = st->sample_aspect_ratio;
+ st2->avg_frame_rate = st->avg_frame_rate;
+ av_dict_copy(&st2->metadata, st->metadata, 0);
+ if ((ret = avcodec_copy_context(st2->codec, st->codec)) < 0)
+ goto fail;
+ }
+
+ if (!(avf2->oformat->flags & AVFMT_NOFILE)) {
+ if ((ret = avio_open(&avf2->pb, filename, AVIO_FLAG_WRITE)) < 0)
+ goto fail;
+ }
+
+ if ((ret = avformat_write_header(avf2, &options)) < 0)
+ goto fail;
+ if (options) {
+ entry = NULL;
+ while ((entry = av_dict_get(options, "", entry, AV_DICT_IGNORE_SUFFIX)))
+ av_log(avf2, AV_LOG_ERROR, "Unknown option '%s'\n", entry->key);
+ ret = AVERROR_OPTION_NOT_FOUND;
+ goto fail;
+ }
+
+ *ravf = avf2;
+ return 0;
+
+fail:
+ av_dict_free(&options);
+ return ret;
+}
+
+static void close_slaves(AVFormatContext *avf)
+{
+ TeeContext *tee = avf->priv_data;
+ AVFormatContext *avf2;
+ unsigned i;
+
+ for (i = 0; i < tee->nb_slaves; i++) {
+ avf2 = tee->slaves[i];
+ avio_close(avf2->pb);
+ avf2->pb = NULL;
+ avformat_free_context(avf2);
+ tee->slaves[i] = NULL;
+ }
+}
+
+static int tee_write_header(AVFormatContext *avf)
+{
+ TeeContext *tee = avf->priv_data;
+ unsigned nb_slaves = 0, i;
+ const char *filename = avf->filename;
+ char *slaves[MAX_SLAVES];
+ int ret;
+
+ while (*filename) {
+ if (nb_slaves == MAX_SLAVES) {
+ av_log(avf, AV_LOG_ERROR, "Maximum %d slave muxers reached.\n",
+ MAX_SLAVES);
+ ret = AVERROR_PATCHWELCOME;
+ goto fail;
+ }
+ if (!(slaves[nb_slaves++] = av_get_token(&filename, slave_delim))) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ if (strspn(filename, slave_delim))
+ filename++;
+ }
+
+ for (i = 0; i < nb_slaves; i++) {
+ if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0)
+ goto fail;
+ av_freep(&slaves[i]);
+ }
+
+ tee->nb_slaves = nb_slaves;
+ return 0;
+
+fail:
+ for (i = 0; i < nb_slaves; i++)
+ av_freep(&slaves[i]);
+ close_slaves(avf);
+ return ret;
+}
+
+static int tee_write_trailer(AVFormatContext *avf)
+{
+ TeeContext *tee = avf->priv_data;
+ AVFormatContext *avf2;
+ int ret_all = 0, ret;
+ unsigned i;
+
+ for (i = 0; i < tee->nb_slaves; i++) {
+ avf2 = tee->slaves[i];
+ if ((ret = av_write_trailer(avf2)) < 0)
+ if (!ret_all)
+ ret_all = ret;
+ if (!(avf2->oformat->flags & AVFMT_NOFILE)) {
+ if ((ret = avio_close(avf2->pb)) < 0)
+ if (!ret_all)
+ ret_all = ret;
+ avf2->pb = NULL;
+ }
+ }
+ close_slaves(avf);
+ return ret_all;
+}
+
+static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
+{
+ TeeContext *tee = avf->priv_data;
+ AVFormatContext *avf2;
+ AVPacket pkt2;
+ int ret_all = 0, ret;
+ unsigned i, s;
+ AVRational tb, tb2;
+
+ for (i = 0; i < tee->nb_slaves; i++) {
+ avf2 = tee->slaves[i];
+ s = pkt->stream_index;
+ if (s >= avf2->nb_streams) {
+ if (!ret_all)
+ ret_all = AVERROR(EINVAL);
+ continue;
+ }
+ if ((ret = av_copy_packet(&pkt2, pkt)) < 0 ||
+ (ret = av_dup_packet(&pkt2))< 0)
+ if (!ret_all) {
+ ret = ret_all;
+ continue;
+ }
+ tb = avf ->streams[s]->time_base;
+ tb2 = avf2->streams[s]->time_base;
+ pkt2.pts = av_rescale_q(pkt->pts, tb, tb2);
+ pkt2.dts = av_rescale_q(pkt->dts, tb, tb2);
+ pkt2.duration = av_rescale_q(pkt->duration, tb, tb2);
+ if ((ret = av_interleaved_write_frame(avf2, &pkt2)) < 0)
+ if (!ret_all)
+ ret_all = ret;
+ }
+ return ret_all;
+}
+
+AVOutputFormat ff_tee_muxer = {
+ .name = "tee",
+ .long_name = NULL_IF_CONFIG_SMALL("Multiple muxer tee"),
+ .priv_data_size = sizeof(TeeContext),
+ .write_header = tee_write_header,
+ .write_trailer = tee_write_trailer,
+ .write_packet = tee_write_packet,
+ .priv_class = &tee_muxer_class,
+ .flags = AVFMT_NOFILE,
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index 73085e0..02ebb8c 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@
#include "libavutil/avutil.h"
#define LIBAVFORMAT_VERSION_MAJOR 54
-#define LIBAVFORMAT_VERSION_MINOR 36
+#define LIBAVFORMAT_VERSION_MINOR 37
#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
--
1.7.10.4
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