[FFmpeg-devel] [libav-devel] [PATCH] nuv: reject negative fps rate

[Andreas Cadhalpun]

On 18.12.2015 12:00, Luca Barbato wrote:
> On 17/12/15 23:01, Andreas Cadhalpun wrote:
>> On 16.12.2015 22:18, Luca Barbato wrote:
>>> On 16/12/15 20:56, Andreas Cadhalpun wrote:
>>>> Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
>>>> ---
>>>>  libavformat/nuv.c | 4 ++++
>>>>  1 file changed, 4 insertions(+)
>>>>
>>>> diff --git a/libavformat/nuv.c b/libavformat/nuv.c
>>>> index 2a1b70f..4cb28d5 100644
>>>> --- a/libavformat/nuv.c
>>>> +++ b/libavformat/nuv.c
>>>> @@ -172,6 +172,10 @@ static int nuv_header(AVFormatContext *s)
>>>>      if (aspect > 0.9999 && aspect < 1.0001)
>>>>          aspect = 4.0 / 3.0;
>>>>      fps = av_int2double(avio_rl64(pb));
>>>> +    if (fps <= 0.0f) {
>>>> +        av_log(s, AV_LOG_ERROR, "Invalid frame rate %f\n", fps);
>>>> +        return AVERROR_INVALIDDATA;
>>>> +    }
>>>>  
>>>>      // number of packets per stream type, -1 means unknown, e.g. streaming
>>>>      v_packs = avio_rl32(pb);
>>>>
>>>
>>> What happens if a negative fps is used?
>>
>> It doesn't make sense. Or what is a negative frame rate supposed to mean?
> 
> So the options are:
> 
> a- not demux at all

That's what my patch does.

> b- mark the framerate as invalid

How does one do that?

> and let the user decide what to do,
> e.g. override it with a value that works for them.
> c- a or b depending on explode.
> 
> A framerate of 0 is the same as a negative framerate for all the
> intended purposes.

So should a negative framerate simply be set to 0?

Best regards,
Andreas