[FFmpeg-devel] [PATCH 2/3] avformat/mux: Avoid overhead of packet list in case of single streams

[Andreas Rheinhardt]

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavformat/internal.h |  7 +++++++
 libavformat/mux.c      | 11 ++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/libavformat/internal.h b/libavformat/internal.h
index 223befdbc0..867b5de514 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -760,6 +760,13 @@ int ff_add_attached_pic(AVFormatContext *s, AVStream *st, AVIOContext *pb,
 int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *pkt,
                                  int flush, int has_packet);
 
+/**
+ * Interleave packets directly in the order in which they arrive
+ * without any sort of buffering.
+ */
+int ff_interleave_packet_passthrough(AVFormatContext *s, AVPacket *pkt,
+                                     int flush, int has_packet);
+
 void ff_free_stream(AVFormatContext *s, AVStream *st);
 
 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
diff --git a/libavformat/mux.c b/libavformat/mux.c
index f4f1bc289e..a6129720dd 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -334,7 +334,10 @@ static int init_muxer(AVFormatContext *s, AVDictionary **options)
         if (par->codec_type != AVMEDIA_TYPE_ATTACHMENT)
             si->nb_interleaved_streams++;
     }
-    si->interleave_packet = of->interleave_packet ? of->interleave_packet : ff_interleave_packet_per_dts;
+    si->interleave_packet = of->interleave_packet ? of->interleave_packet :
+                                si->nb_interleaved_streams > 1 ?
+                                    ff_interleave_packet_per_dts :
+                                    ff_interleave_packet_passthrough;
 
     if (!s->priv_data && of->priv_data_size > 0) {
         s->priv_data = av_mallocz(of->priv_data_size);
@@ -1026,6 +1029,12 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *pkt,
     }
 }
 
+int ff_interleave_packet_passthrough(AVFormatContext *s, AVPacket *pkt,
+                                     int flush, int has_packet)
+{
+    return has_packet;
+}
+
 int ff_get_muxer_ts_offset(AVFormatContext *s, int stream_index, int64_t *offset)
 {
     AVStream *st;
-- 
2.30.2