The function now accepts an existing buffer to avoid unnecessary allocations,
as well as only reporting the needed amount of bytes if you pass a NULL pointer
as input for data.
For this, both parameters become input and output, as well as making data
optional. This is backwards compatible, and as such not breaking any existing
use of the function in external code (if there's any).
Signed-off-by: James Almer <jamrial@gmail.com>
The dynamic metadata contains data for color volume transform -
application 4 of SMPTE 2094-40:2016 standard. The data comes from
HEVC in the SEI_TYPE_USER_DATA_REGISTERED_ITU_T_T35.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
