[vlc-devel] [RFC PATCH 3.0.x] input: clear EOF flags of slave sources when select track

[Rémi Denis-Courmont]

Le vendredi 13 novembre 2020, 16:06:37 EET Zhao Zhili a écrit :
> input-slave was broken for some demuxers like mp4. If no track is
> selected, slave demuxer return EOF at the beginning. Selecting
> a track of slave input doesn't work since the input source is
> in the EOF status. For VLC users, seeking after select track is a
> workaround solution, because seek will reset the EOF flag.
> 
> Since a video track can be enabled at random position and there is
> no preroll, it can lead to corrupted frames.

I don't think you can simply undo the EOS flag. AFAIK, demuxers are not 
*generally* robust enough to return EOS repeatedly.

Most likely some demuxers return a fatal error or even crash if you try to 
demux after EOS (without first seeking). We can agree that that's a bug in any 
affected demuxers ... in 4.0. But we can't just decree a change in the API 
semantics, without first reviewing the demuxers.

It's unlikely that we can do this in a stable release at all.

-- 
Rémi Denis-Courmont