On Tue, Sep 1, 2015 at 11:57 AM, David Singer <sin...@apple.com> wrote:

> > On Sep 1, 2015, at 11:36 , Kevin Marks <kevinma...@gmail.com> wrote:
> > > I suppose the browser could generate this data the first time it reads
> through the video. It would use a lot less memory. Though that sounds like
> a problem for the browsers to solve, not the standard.
> >
> > There is no *generation* on the browser side; these tables are part of
> the file format.
> >
> > Well, when it imports stream-oriented media it has to construct these in
> memory, but they can be saved out again. I know that in theory this made
> its way into the mp4 format, but I'm not sure how much of it is real.
> Two different questions:
> a) do the QuickTime movie file format and the MP4 format contain these
> tables?  Yes.
> b) if I open another format, what happens?
> For case (a), the situation may be more nuanced if Movie Fragments are in
> use (you then get the tables for each fragment of the movie, though they
> are easily coalesced as they arrive).
> For case (b), classic QuickTime used to ‘convert to movie’ in memory,
> building the tables.  The situation is more nuanced on more recent engines.
> I think the point of the discussion is that one cannot dismiss trick modes
> such as reverse play as being unimplementable.

The other point for me is that given http://aomedia.org/ announcing plans
to create a new video file format to fix everything, that this time we
actually learn from this history and make one that is editable and seekable

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