[FFmpeg-user] Setting colour range.

[Gyan Doshi]

On 27-11-2018 08:59 PM, Kieran O Leary wrote:

> 
> Can this metadata ever be set at a container level for mov? Must it always
> be the stream that holds this info?

The muxer only writes it for MP4s,

The QT spec doesn't accommodate its signaling :

     "In scheme A, Cb and Cr have a 2n-2 (254 for n=8 bits) excursion 
while Y´ has a 2n-1 (255 for n=8 bits) excursion. Furthermore, ECb=0 and 
ECr=0 imply Cb=0 and Cr=0, respectively (Cb and Cr have a 0 center). You 
may encounter video data with two's complement Cb and Cr components that 
have other excursions and centers. In particular, you may encounter data 
with a 2n-1 (255 for n=8 bits) excursion and a -0.5 center, which is 
known as a "Full-Range" mapping. You may also encounter data with a 2n 
excursion (256 for n=8 bits) and a 0 center. These forms of data are not 
representable using the labels described in this document. Be sure to 
convert the data properly when bringing it into QuickTime using a 
compression type from this document. Failure to so could, for example, 
incorrectly generate the value -2n-1."

from

 
https://developer.apple.com/library/archive/technotes/tn2162/_index.html#//apple_ref/doc/uid/DTS40013070-CH1-TNTAG7



Gyan