[vlc-devel] [PATCH 1/1] dvdnav: add external access module support

[Rémi Denis-Courmont]

Le 2015-03-12 16:01, Petri Hintukainen a écrit :
> On to, 2015-03-12 at 15:51 +0300, Rémi Denis-Courmont wrote:
>> Le 2015-03-12 13:10, Jean-Baptiste Kempf a écrit :
>> >> It´s far from that easy. dvdnav and dvdread normally use regular
>> >> files or block
>> >> devices. They cannot "block", they either return success or a 
>> fatal
>> >> error
>> >> immediately (from a scheduling point of view).
>> >
>> > They can, with the new callback system.
>>
>> Like no? The new callbacks are still dependent on regular file read
>> semantics.
>
> Other demuxers read and seek the stream too while probing in Open(),
> how is this different ?

That really is the same bug. But regular demuxers have at least been 
written to limit the scope of the problem. In particular, they do not 
read large blocks at once, and they avoid seeking as much as possible 
(unless the stream has FASTSEEK support).

Optical discs demuxers have not been written with anything but 
non-blocking reads mind. I would think that BD is going to be worse than 
DVD in this respect, especially with Java involved.

-- 
Rémi Denis-Courmont