[FFmpeg-devel] [PATCH] Write Pixel Aspect Ratio tag to QuickTime files

[Baptiste Coudurier]

On 7/7/10 7:36 PM, Jean-Daniel Dupas wrote:
>
> Le 8 juil. 2010 ? 04:22, Baptiste Coudurier a ?crit :
>
>> On 07/07/2010 07:12 PM, Daniel Kristjansson wrote:
>>> On Wed, 2010-07-07 at 14:35 -0700, Baptiste Coudurier wrote:
>>>> On 07/07/2010 02:17 PM, Daniel Kristjansson wrote:
>>>>> It's required in the spec, p118 of qtfs.pdf, "Pixel aspect ratio. This
>>>>> extension is mandatory for video formats that use non-square pixels."
>>>> My specs say MPEG-4 and uncompresed YCbCr. Dated 2007-09-04
>>>
>>> Mine is dated 2010-05-03.
>>
>> Nice a new one :)
>> Unbelievable that they still refuses to document the 'ctts' atom ...
>
> This is the version with the QuickTime meta data format specification (keys/ilst atoms).
>
> http://developer.apple.com/mac/library/documentation/QuickTime/QTFF/RevHistory/QTFFrevision_history.html#//apple_ref/doc/uid/TP40000939-CH228-SW1
>
> FWIW, the ctts atom is fully documented in the MPEG-4 part12 specification [8.6.1.3] (except that they use signed offset despite what the spec says).

Yes, I know that. I was referring to their "signed" offset variant which 
goes like you said, against ISO 14496-12. ISO will add that variant 
using version 1 of the atom.

-- 
Baptiste COUDURIER
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