[vlc-devel] [PATCH 00/17] RFC Split block_t into 2 different data containers
remi at remlab.net
Wed Apr 24 16:23:41 CEST 2019
Le keskiviikkona 24. huhtikuuta 2019, 16.57.15 EEST Thomas Guillem a écrit :
> Hello TypX,
> I also 2 other issues with this RFC:
> - Drop of flags in vlc_data_t: sadly, there will be no ways for accesses to
> report a discontinuity.
That's a feature. You cannot have flags in a byte stream as you've reminded
> I know it is broken in VLC 3.0 since flags are lost
> in stream filters, but there are a lot of requests to bring back the
> ability for accesses to notify a discontinuity.
That was not "broken in VLC 3.0". The only stream_t function that could
preserve packet boundaries, and thus flags, is vlc_stream_ReadBlock() which was
introduced in 3.0, much later than stream filters.
Besides, even before streams filters existed, the stream buffering code in the
core did much the same as stream filters do today. This is really as old as the
So there never was an option to pass flags there. In particular, what V4L2
access does is just cargo cult from the V4L2 access_demux.
> We should fix it for 4.0
> and therefore keep this flag.
I completely disagree. That is an impossible/inconsistent requirement.
If you have packets with flags, don't use the the stream abstraction. Even if
that worked through stream filters, it would confuse the demuxers behind it. So
you need tight coupling anyway.
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