[FFmpeg-devel] [PATCH] Add SUP/PGS subtitle demuxer

wm4 nfxjfg at googlemail.com
Sun Aug 31 12:00:13 CEST 2014

On Sun, 31 Aug 2014 11:50:36 +0200
Reimar Döffinger <Reimar.Doeffinger at gmx.de> wrote:

> On Sun, Aug 31, 2014 at 11:39:16AM +0200, wm4 wrote:
> > I got the semantics of avio_read wrong: short reads on EOF are in
> > fact allowed and don't return an error. Hopefully this is correct now...
> What I _really_ dislike about these approaches is that we hard-code EOF
> behaviour in every single demuxer.
> So some will return partial packets some won't.
> And if we wanted to make that behaviour configurable we'd have to add
> options to every single one instead of changing the code in one single
> place.
> Not to mention all the other optimizations, just look how much e.g.
> av_get_packet actually does!
> Why do you absolutely want to handle this manually via avio_read?
> You can just use av_get_packet + av_append_packet, then you only need
> to check the size once, and you also don't have to set "pkt->pos"
> manually and you still don't have to do seekback.

I wasn't aware of av_get/append_packet() (sorry if it was mentioned
before and I ignored it) - it looks nice. I'll try to use it and send a
patch again later. It's a bit not-nice that it reallocs the packet, but
there's probably no way it matters in this case at all.

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