[FFmpeg-devel] current way to tell if image is bottom up -possible bug

Don Moir donmoir at comcast.net
Thu Aug 23 20:26:55 CEST 2012

On Thu, Aug 23, 2012 at 01:56:04PM -0400, Don Moir wrote:
>> It used to be that you could check AVCodecContext.extradata for 
>> "BottomUp" to determine if an image was bottom up.
>> That no longer works and AVCodecContext.extradata is null.
>> So is there a new way to determine this or does this need to be reported 
>> as a bug?
>> I have a video that is now upside down because I cannot determine the 
>> orientation from ffmpeg as far as I can tell. It's also upside down in 
>> ffplay.

>> It worked before but not sure how long ago that was.

>if it worked before (in ffplay for example, and fails now)
>then its a bug

So your saying extradata should contain "BottomUp" in this case? I always 
thought this was a bit strange and thinking a flag should be used instead.

I don't know for sure if it ever worked in ffplay because I don't think 
ffplay ever checked for "BottomUp". Just saying its upside down in ffplay.

For me, I check for "BottomUp" and invert if necessary and no longer can do.

Just reply and I will report it as a bug. 

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