[FFmpeg-devel] [PATCH] avcodec/extract_extradata: zero initialize the padding bytes of the exported extradata

wm4 nfxjfg at googlemail.com
Fri Mar 9 23:40:30 EET 2018


On Fri, 9 Mar 2018 21:57:38 +0100
Hendrik Leppkes <h.leppkes at gmail.com> wrote:

> On Fri, Mar 9, 2018 at 9:52 PM, wm4 <nfxjfg at googlemail.com> wrote:
> > On Fri, 9 Mar 2018 13:31:45 -0300
> > James Almer <jamrial at gmail.com> wrote:
> >  
> >> On 3/9/2018 12:47 PM, Derek Buitenhuis wrote:  
> >> > On 3/9/2018 3:22 PM, James Almer wrote:  
> >> >> Yes, but it's slower, and the buffer is guaranteed to be written to with
> >> >> actual data after being allocated.
> >> >>
> >> >> This is a filter that may run once per processed packet, so the less
> >> >> overhead the better.  
> >> >
> >> > Not sure I buy the "speed" argument here, but OK.
> >> >
> >> > - Derek  
> >>
> >> There's really nothing to win zeroing then immediately writing actual
> >> data on top of it.
> >>  
> >
> > Except code clarity and robustness?  
> 
> We use this sort of pattern in all sorts of places where buffers are
> read and padded. Its clear enough.

Well, the fact that there are patches every once in a while that fix
places where this was not correctly done could hint otherwise. Not that
I want to make a huge discussion about it (though I always disliked
this padding requirement).


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