[vlc-devel] [PATCH 1/9] video_format: add the number of fields per picture in the video format

[Francois Cartegnie]

Le 16/11/2020 à 14:00, Romain Vimont a écrit :
> On Mon, Nov 16, 2020 at 01:44:12PM +0100, Steve Lhomme wrote:
>> In general it's 2 fields. If the number of fields changes in the source, the
>> (deinterlacing) filters should be updated.
>>
>> By default the video format is progressive and the i_num_fields can be ignored.
>> It should be set to 2 for progressive to be consistent with how the value was
>> set so far.
>>
>> This field is more stable than the picture i_nb_fields that also included
>> repeated fields and pictures. It only contains the information about the
>> number of fields in each actual picture.
>> ---

Or not that simple.

Maybe, since this is format and no longer picture_t specific, we should 
use an enum with all cases as exposed in MPEG protocols which also 
specifies the associativity of the field.


-- 
Francois Cartegnie
VideoLAN - VLC Developer