[FFmpeg-devel] [PATCH] libavformat/avidec: subtitle stream disable some non-interleaved process

[tiejun.peng]

non-interleaved process call avio_seek frequently, it will cause some performance issues especially in network play scene, such as http/ftp protocol.

Signed-off-by: tiejun.peng <tiejun.peng at foxmail.com>
---
 libavformat/avidec.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index b8a31dc..0220ea1 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -1520,7 +1520,8 @@ resync:
         }
         ast->seek_pos= 0;
 
-        if (!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1) {
+        /* subtitle stream no need the next process, because subtitle's pkt->dts is always 0 */
+        if (!avi->non_interleaved && st->nb_index_entries>1 && avi->index_loaded>1 && st->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
             int64_t dts= av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);
 
             if (avi->dts_max - dts > 2*AV_TIME_BASE) {
@@ -1646,6 +1647,10 @@ static int check_stream_max_drift(AVFormatContext *s)
             AVStream *st = s->streams[i];
             AVIStream *ast = st->priv_data;
             int n = st->nb_index_entries;
+            /* when stream is subtitle, don't change min_dts, because subtitle stream's dts is always 0 */
+            if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE)
+                continue;
+
             while (idx[i] < n && st->index_entries[idx[i]].pos < pos)
                 idx[i]++;
             if (idx[i] < n) {
@@ -1661,6 +1666,10 @@ static int check_stream_max_drift(AVFormatContext *s)
             AVStream *st = s->streams[i];
             AVIStream *ast = st->priv_data;
 
+            /* when stream is subtitle, don't change max_dts, because subtitle stream's dts is always 0 */
+            if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE)
+                continue;
+
             if (idx[i] && min_dts != INT64_MAX / 2) {
                 int64_t dts;
                 dts = av_rescale_q(st->index_entries[idx[i] - 1].timestamp /
-- 
2.7.4