aviobuf: Do short seeks forward by reading and skipping data instead of a proper seek

This improves performance on e.g. seekable http.

Originally committed as revision 24280 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Martin Storsjö 2010-07-17 05:26:30 +00:00
parent a58e6ceae0
commit 7939d0edce

View File

@ -28,6 +28,13 @@
#define IO_BUFFER_SIZE 32768
/**
* Do seeks within this distance ahead of the current buffer by skipping
* data instead of calling the protocol seek function, for seekable
* protocols.
*/
#define SHORT_SEEK_THRESHOLD 4096
static void fill_buffer(ByteIOContext *s);
#if LIBAVFORMAT_VERSION_MAJOR >= 53
static int url_resetbuf(ByteIOContext *s, int flags);
@ -153,7 +160,9 @@ int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
/* can do the seek inside the buffer */
s->buf_ptr = s->buffer + offset1;
} else if(s->is_streamed && !s->write_flag && offset1 >= 0 &&
} else if ((s->is_streamed ||
offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
!s->write_flag && offset1 >= 0 &&
(whence != SEEK_END || force)) {
while(s->pos < offset && !s->eof_reached)
fill_buffer(s);