[FFmpeg-devel] [PATCH] do not fail if aspect ratio is forbidden in mpeg-2

[Ivan Kalvachev]

On Thu, Mar 13, 2008 at 8:27 PM, Baptiste Coudurier
<baptiste.coudurier at smartjog.com> wrote:
> Michael Niedermayer wrote:
>  > On Thu, Mar 13, 2008 at 07:09:51PM +0100, Baptiste Coudurier wrote:
>  >> Hi,
>  >>
>  >> $subject.
>  >>
>  >> Yes, value 0 is forbidden in the specs (ISO 13818-2), however IMHO it is
>  >> a bit harsh to fail badly (libmpeg2 does not fail)
>  >>
>  >> This fixes issue 369.
>  >
>  > ok
>  >
>
>  Applied.

That commit was quick.

However I'm not happy with it. The value of zero is not reserved, it
is forbidden. In theory forbidden values are values that could lead to
startcode emulation.

The sample doesn't seem to contain another sequence header so there is
no way to check if this sample is accidentally or systematically
broken.

I guess that libmpeg2 accepting broken codes is bug, that library is
known to have error resilience issues.

Anyway, as Michael accepted it so I won't request this to be reverted.
I'd however request this "broken" behavior to be bound to
"error_resilience" or "strict_std_compliance" .