[FFmpeg-devel] [PATCH] avformat/aviobuf: fix broken logic in ffio_ensure_seekback()

[Paul B Mahol]

On Sat, Sep 26, 2020 at 12:50:34PM +0200, Michael Niedermayer wrote:
> On Thu, Sep 17, 2020 at 12:31:06PM +0200, Paul B Mahol wrote:
> > This removes big CPU overhead for demuxing chained ogg streams.
> > 
> > Signed-off-by: Paul B Mahol <onemda at gmail.com>
> > ---
> >  libavformat/aviobuf.c | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> I think we need some fate test for ffio_ensure_seekback()
> as our tests are ATM we generally have fully seekable inputs so
> failure of seekback would not be noticed.
> 
> This is a problem because the buffer IO stuff is not easy to
> understand and so it is time consuming and error prone to review these patches
> just by eye. And as we see developers disagree on what is correct
> 
> Such fate test should at least test various sequentially occuring
> ffio_ensure_seekback(), a possibly larger initial buffer from probing
> as well as its later reduction. And also reading requests failing, early EOF
> seeking, and IO errors

Well, if its documented that ffio_ensure_seekback() can not flush buffer
than there should be added code/function to do allow flushing.

Because oggdec works fine with assumed flushing and my patch.

> 
> thanks
> 
> [...]
> 
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> The day soldiers stop bringing you their problems is the day you have stopped 
> leading them. They have either lost confidence that you can help or concluded 
> you do not care. Either case is a failure of leadership. - Colin Powell



> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".