[FFmpeg-cvslog] avformat/aviobuf: optimize sequential backward seeking

Michael Niedermayer git at videolan.org
Sun Mar 2 00:16:06 CET 2014


ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Mar  1 23:09:40 2014 +0100| [9600486d10a9728f1503363334268ecfafa9b0e5] | committer: Michael Niedermayer

avformat/aviobuf: optimize sequential backward seeking

This reduces the number of protocol seeks

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9600486d10a9728f1503363334268ecfafa9b0e5
---

 libavformat/aviobuf.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 18431e7..95fdf20 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -234,9 +234,20 @@ int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
         if (s->eof_reached)
             return AVERROR_EOF;
         s->buf_ptr = s->buf_end + offset - s->pos;
-    } else {
+    } else if(!s->write_flag && offset1 < 0 && -offset1 < buffer_size>>1 && s->seek && offset > 0) {
         int64_t res;
 
+        pos -= FFMIN(buffer_size>>1, pos);
+        if ((res = s->seek(s->opaque, pos, SEEK_SET)) < 0)
+            return res;
+        s->buf_end =
+        s->buf_ptr = s->buffer;
+        s->pos = pos;
+        s->eof_reached = 0;
+        fill_buffer(s);
+        return avio_seek(s, offset, SEEK_SET | force);
+    } else {
+        int64_t res;
         if (s->write_flag) {
             flush_buffer(s);
             s->must_flush = 1;



More information about the ffmpeg-cvslog mailing list