[FFmpeg-devel] [PATCH] libavutil: AVEncodeInfo data structures

[Nicolas George]

Juan De León (12019-08-13):
> The array is there so that the structure isn't opaque, it should be
> accessed with the function.

I realize you need it, but not for the reason you say. It is needed for
alignment: if blocks needs more alignment than info, info+sizeof(info)
is not a valid pointer for blocks.

> > > +    if (!info || idx >= info->nb_blocks || idx < 0)
> > > +        return NULL;
> > How valid is it for applications to call with idx outside the range?
> They shouldn't but I figure it's better to return NULL than to get
> undefined behaviour.

In that case, I think is is better practice to document:

	Index must be between 0 and nb_blocks

and check with an assert, forcing the application programmer fix their
code immediately.

Most code will likely use idx from a loop counter, where it cannot be
outside the range, and for the few other cases, the caller can do the
check if necessary.

Also, make the fields that cannot be negative unsigned, and you can drop
the <0 test.

Regards,

-- 
  Nicolas George
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