[FFmpeg-cvslog] avformat: make flush_packets a tri-state and set it to -1 (auto) by default
Marton Balint
git at videolan.org
Sat Jun 24 20:12:55 EEST 2017
ffmpeg | branch: master | Marton Balint <cus at passwd.hu> | Sun Jun 4 04:19:33 2017 +0200| [eeeb595c7f1c78764a1a670b763fa837ab3db2bd] | committer: Marton Balint
avformat: make flush_packets a tri-state and set it to -1 (auto) by default
If flushing is not disabled, then mux.c will signal the end of the packets with
an AVIO_DATA_MARKER_FLUSH_POINT, and aviobuf will be able to decide to flush or
not based on the preferred minimum packet size set by the used protocol.
Reviewed-by: Michael Niedermayer <michael at niedermayer.cc>
Signed-off-by: Marton Balint <cus at passwd.hu>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=eeeb595c7f1c78764a1a670b763fa837ab3db2bd
---
doc/formats.texi | 7 ++++---
libavformat/mux.c | 19 +++++++++++++------
libavformat/options_table.h | 4 ++--
3 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/doc/formats.texi b/doc/formats.texi
index c51d4086db..ddd7743548 100644
--- a/doc/formats.texi
+++ b/doc/formats.texi
@@ -182,9 +182,10 @@ Default is 0.
Correct single timestamp overflows if set to 1. Default is 1.
@item flush_packets @var{integer} (@emph{output})
-Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
+Flush the underlying I/O stream after each packet. Default is -1 (auto), which
+means that the underlying protocol will decide, 1 enables it, and has the
+effect of reducing the latency, 0 disables it and may increase IO throughput in
+some cases.
@item output_ts_offset @var{offset} (@emph{output})
Set the output time offset.
diff --git a/libavformat/mux.c b/libavformat/mux.c
index e1e49a81be..53ad46df42 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -468,6 +468,16 @@ static int init_pts(AVFormatContext *s)
return 0;
}
+static void flush_if_needed(AVFormatContext *s)
+{
+ if (s->pb && s->pb->error >= 0) {
+ if (s->flush_packets == 1 || s->flags & AVFMT_FLAG_FLUSH_PACKETS)
+ avio_flush(s->pb);
+ else if (s->flush_packets && !(s->oformat->flags & AVFMT_NOFILE))
+ avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_FLUSH_POINT);
+ }
+}
+
static int write_header_internal(AVFormatContext *s)
{
if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
@@ -479,8 +489,7 @@ static int write_header_internal(AVFormatContext *s)
s->internal->write_header_ret = ret;
if (ret < 0)
return ret;
- if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
- avio_flush(s->pb);
+ flush_if_needed(s);
}
s->internal->header_written = 1;
if (!(s->oformat->flags & AVFMT_NOFILE) && s->pb)
@@ -772,8 +781,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
}
if (s->pb && ret >= 0) {
- if (s->flush_packets && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
- avio_flush(s->pb);
+ flush_if_needed(s);
if (s->pb->error < 0)
ret = s->pb->error;
}
@@ -932,8 +940,7 @@ int av_write_frame(AVFormatContext *s, AVPacket *pkt)
return ret;
}
ret = s->oformat->write_packet(s, NULL);
- if (s->flush_packets && s->pb && s->pb->error >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
- avio_flush(s->pb);
+ flush_if_needed(s);
if (ret >= 0 && s->pb && s->pb->error < 0)
ret = s->pb->error;
return ret;
diff --git a/libavformat/options_table.h b/libavformat/options_table.h
index 0c1915d6d4..118086df66 100644
--- a/libavformat/options_table.h
+++ b/libavformat/options_table.h
@@ -39,7 +39,7 @@ static const AVOption avformat_options[] = {
{"probesize", "set probing size", OFFSET(probesize), AV_OPT_TYPE_INT64, {.i64 = 5000000 }, 32, INT64_MAX, D},
{"formatprobesize", "number of bytes to probe file format", OFFSET(format_probesize), AV_OPT_TYPE_INT, {.i64 = PROBE_BUF_MAX}, 0, INT_MAX-1, D},
{"packetsize", "set packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, 0, INT_MAX, E},
-{"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_FLUSH_PACKETS | AVFMT_FLAG_AUTO_BSF }, INT_MIN, INT_MAX, D|E, "fflags"},
+{"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_AUTO_BSF }, INT_MIN, INT_MAX, D|E, "fflags"},
{"flush_packets", "reduce the latency by flushing out packets immediately", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FLUSH_PACKETS }, INT_MIN, INT_MAX, E, "fflags"},
{"ignidx", "ignore index", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_IGNIDX }, INT_MIN, INT_MAX, D, "fflags"},
{"genpts", "generate pts", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_GENPTS }, INT_MIN, INT_MAX, D, "fflags"},
@@ -85,7 +85,7 @@ static const AVOption avformat_options[] = {
{"use_wallclock_as_timestamps", "use wallclock as timestamps", OFFSET(use_wallclock_as_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, D},
{"skip_initial_bytes", "set number of bytes to skip before reading header and frames", OFFSET(skip_initial_bytes), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX-1, D},
{"correct_ts_overflow", "correct single timestamp overflows", OFFSET(correct_ts_overflow), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, D},
-{"flush_packets", "enable flushing of the I/O context after each packet", OFFSET(flush_packets), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, E},
+{"flush_packets", "enable flushing of the I/O context after each packet", OFFSET(flush_packets), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, E},
{"metadata_header_padding", "set number of bytes to be written as padding in a metadata header", OFFSET(metadata_header_padding), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, E},
{"output_ts_offset", "set output timestamp offset", OFFSET(output_ts_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX, INT64_MAX, E},
{"max_interleave_delta", "maximum buffering duration for interleaving", OFFSET(max_interleave_delta), AV_OPT_TYPE_INT64, { .i64 = 10000000 }, 0, INT64_MAX, E },
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