[FFmpeg-cvslog] r22197 - trunk/libavformat/matroskaenc.c

[Reimar Döffinger]

On Thu, Mar 04, 2010 at 10:56:37PM +0000, M?ns Rullg?rd wrote:
> Reimar D?ffinger <Reimar.Doeffinger at gmx.de> writes:
> > On Thu, Mar 04, 2010 at 09:27:53PM +0000, M?ns Rullg?rd wrote:
> >> Reimar D?ffinger <Reimar.Doeffinger at gmx.de> writes:
> >> > On Thu, Mar 04, 2010 at 07:42:05PM +0000, M?ns Rullg?rd wrote:
> >> >> Reimar D?ffinger <Reimar.Doeffinger at gmx.de> writes:
> >> >> > So above code adds the assumption that seeking backwards will be either
> >> >> > reasonably fast or fail even in the url_is_streamed case, while the
> >> >> > documentation would not even give someone implementing a protocol any hint
> >> >> > about this - they might reasonably say "well, seek is so horribly slow
> >> >> > we absolutely need avoid it, so we set is_streamed, however we would still
> >> >> > be able to somehow play formats that absolutely require seeking, so we implement
> >> >> > it anyway". If they wanted it to work well with the matroska muxer too they
> >> >> > now would have to add a special hack...
> >> >> 
> >> >> The protocol seek function _is never called_ in this case.  No, the
> >> >> documentation of url_fseek() doesn't mention this.  Patches welcome.
> >> >
> >> > Either I'm blind again or you have no idea what you are talking about...
> >> > The seek function is called even for is_streamed if it is considered
> >> > necessary, and I consider than good and sensible behaviour, however
> >> > it somewhat clashes with this newly added code.
> >> > Now it's not such an important issue, but considering that at least one
> >> > of us is confused I conclude it wasn't such a bad idea to mention it anyway.
> >> 
> >> The low-level seek function is only called if the seek target is
> >> outside the buffer.  This is handled in generic code, and protocols
> >> need not worry.  Why don't you go and read the source yourself?
> >
> > I've been talking only and exclusively about the case when the seek
> > is outside the buffer,
> 
> But in this case the seek is within the buffer.

At least the commit message only says "most" so I expect it will be outside
at least occasionally...