Quite low latency streaming would enjoy sparing the muxer setup time
when possible.
The segment muxer would be simplified a lot and the mpegts corner case
would be solved clearly.
Any application using more than once a muxer could spare a deinit/init
cycle.
---
Now with documentation and both ends covered
libavformat/avformat.h | 73 +++++++++++++++++++++++++++++++
libavformat/mux.c | 115 ++++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 177 insertions(+), 11 deletions(-)
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index f9f39a6..32db1b3 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -407,7 +407,22 @@ typedef struct AVOutputFormat {
*/
int priv_data_size;
+ /**
+ * Initialize the muxer context and write the header.
+ * @deprecated implement the split functions below.
+ */
int (*write_header)(struct AVFormatContext *);
+
+ /**
+ * Initialize the muxer context.
+ */
+ int (*init)(struct AVFormatContext *);
+
+ /**
+ * Write the header, requires an initialized context.
+ */
+ int (*write_header2)(struct AVFormatContext *);
+
/**
* Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
* pkt can be NULL in order to flush data buffered in the muxer.
@@ -416,7 +431,13 @@ typedef struct AVOutputFormat {
* data.
*/
int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
+
int (*write_trailer)(struct AVFormatContext *);
+
+ int (*write_trailer2)(struct AVFormatContext *);
+
+ int (*deinit)(struct AVFormatContext *);
+
/**
* Currently only used to set pixel format if not YUV420P.
*/
@@ -1427,6 +1448,35 @@ void avformat_close_input(AVFormatContext **s);
int avformat_write_header(AVFormatContext *s, AVDictionary **options);
/**
+ * Allocate the stream private data.
+ *
+ * @param s Media file handle, must be allocated with avformat_alloc_context().
+ * Its oformat field must be set to the desired output format;
+ * Its pb field must be set to an already openened AVIOContext.
+ * @param options An AVDictionary filled with AVFormatContext and
muxer-private options.
+ * On return this parameter will be destroyed and replaced
with a dict containing
+ * options that were not found. May be NULL.
+ *
+ * @return 0 on success, negative AVERROR on failure.
+ *
+ * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
+ */
+int avformat_mux_init(AVFormatContext *s, AVDictionary **options);
+
+/**
+ * Write the stream header to an output media file.
+ *
+ * @param s Media file handle, must be initialized by avformat_mux_init().
+ * Its oformat field must be set to the desired output format;
+ * Its pb field must be set to an already openened AVIOContext.
+ *
+ * @return 0 on success, negative AVERROR on failure.
+ *
+ * @see avio_open, av_oformat_next, avformat_mux_init.
+ */
+int avformat_mux_header(AVFormatContext *s);
+
+/**
* Write a packet to an output media file.
*
* The packet shall contain one audio or video frame.
@@ -1494,6 +1544,29 @@ int av_interleave_packet_per_dts(AVFormatContext *s,
AVPacket *out,
int av_write_trailer(AVFormatContext *s);
/**
+ * Write the stream trailer to an output media file.
+ *
+ * May only be called after a successful call to av_write_header or
+ * avformat_mux_init.
+ *
+ * Can be safely called multiple times.
+ *
+ * @param s media file handle
+ * @return 0 if OK, AVERROR_xxx on error
+ */
+int avformat_mux_trailer(AVFormatContext *s);
+
+/**
+ * Free the file private data.
+ *
+ * May only be called after a successful call to av_write_header or
+ * avformat_mux_init.
+ *
+ * @param s media file handle
+ */
+void avformat_mux_deinit(AVFormatContext *s);
+
+/**
* Return the output format in the list of registered output formats
* which best matches the provided parameters, or return NULL if
* there is no match.
diff --git a/libavformat/mux.c b/libavformat/mux.c
index 96eecb5..28074fa 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -303,6 +303,17 @@ int avformat_write_header(AVFormatContext *s, AVDictionary
**options)
ret = s->oformat->write_header(s);
if (ret < 0)
return ret;
+ } else {
+ if (s->oformat->init) {
+ ret = s->oformat->init(s);
+ if (ret < 0)
+ return ret;
+ }
+ if (s->oformat->write_header2) {
+ ret = s->oformat->write_header2(s);
+ if (ret < 0)
+ return ret;
+ }
}
if ((ret = init_pts(s) < 0))
@@ -311,6 +322,38 @@ int avformat_write_header(AVFormatContext *s, AVDictionary
**options)
return 0;
}
+int avformat_mux_init(AVFormatContext *s, AVDictionary **options)
+{
+ int ret = 0;
+
+ if (ret = init_muxer(s, options))
+ return ret;
+
+ if (s->oformat->init) {
+ ret = s->oformat->init(s);
+ if (ret < 0)
+ return ret;
+ }
+
+ if ((ret = init_pts(s) < 0))
+ return ret;
+
+ return 0;
+}
+
+int avformat_mux_header(AVFormatContext *s)
+{
+ int ret = 0;
+
+ if (s->oformat->write_header2) {
+ ret = s->oformat->write_header2(s);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
//FIXME merge with compute_pkt_fields
static int compute_pkt_fields2(AVFormatContext *s, AVStream *st, AVPacket *pkt)
{
@@ -562,15 +605,14 @@ int av_interleaved_write_frame(AVFormatContext *s,
AVPacket *pkt)
}
}
-int av_write_trailer(AVFormatContext *s)
+static int flush_trailing_packets(AVFormatContext *s)
{
- int ret, i;
+ int ret = 0;
- for (;; ) {
+ for (;;) {
AVPacket pkt;
ret = interleave_packet(s, &pkt, NULL, 1);
- if (ret < 0) //FIXME cleanup needed for ret<0 ?
- goto fail;
+ //FIXME cleanup needed for ret < 0 ?
if (!ret)
break;
@@ -581,22 +623,73 @@ int av_write_trailer(AVFormatContext *s)
av_free_packet(&pkt);
if (ret < 0)
- goto fail;
+ break;
}
- if (s->oformat->write_trailer)
- ret = s->oformat->write_trailer(s);
+ return ret;
+}
- if (!(s->oformat->flags & AVFMT_NOFILE))
- avio_flush(s->pb);
+void avformat_mux_deinit(AVFormatContext *s)
+{
+ int i;
+
+ if (s->oformat->deinit) {
+ s->oformat->deinit(s);
+ }
-fail:
for (i = 0; i < s->nb_streams; i++) {
av_freep(&s->streams[i]->priv_data);
av_freep(&s->streams[i]->index_entries);
}
+
if (s->oformat->priv_class)
av_opt_free(s->priv_data);
av_freep(&s->priv_data);
+}
+
+int avformat_mux_trailer(AVFormatContext *s)
+{
+ int ret;
+
+ ret = flush_trailing_packets(s);
+ if (ret < 0)
+ return ret;
+
+ if (s->oformat->write_trailer2) {
+ ret = s->oformat->write_trailer2(s);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (!(s->oformat->flags & AVFMT_NOFILE))
+ avio_flush(s->pb);
+
return ret;
}
+
+int av_write_trailer(AVFormatContext *s)
+{
+ int ret;
+
+ ret = flush_trailing_packets(s);
+ if (ret < 0)
+ goto fail;
+
+ if (s->oformat->write_trailer)
+ ret = s->oformat->write_trailer(s);
+ else {
+ if (s->oformat->write_trailer2) {
+ ret = s->oformat->write_trailer2(s);
+ if (ret < 0)
+ goto fail;
+ }
+ }
+
+ if (!(s->oformat->flags & AVFMT_NOFILE))
+ avio_flush(s->pb);
+
+fail:
+ avformat_mux_deinit(s);
+ return ret;
+}
+
--
1.7.12
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