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

[Baptiste Coudurier]

Hi,

Michael Niedermayer wrote:
> On Thu, Mar 13, 2008 at 10:08:49PM +0200, Ivan Kalvachev wrote:
>> 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" .
> 
> Iam fine with that, we could also add a warning so the user knows that
> the file is not ok and why.
> 

Added a message, and code fail is error_resilience is >= FF_ER_COMPLIANT.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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