[FFmpeg-devel] H.264 + PAFF: BBC HD recording shows extreme interlacing artefacts

[Jeff Downs]

On Thu, 1 Nov 2007, Michael Niedermayer wrote:

> > Well, I had a look into the spec and into h264.c and cannot find any
> > other variable which explicitly tells me "bottom_field_first" than
> > picture_structure.
> 
> maybe field_poc could be used,i dunno if this is how its supposed to be
> detected though

Annex C, Section 4 talks about removal from the DPB for output in the 
Hypothetical Reference Decoder.  In there they discuss output order based 
on POC and decoding order.

Not sure if this is what you are looking for (I'm not familiar with the 
top_field_first flag that's interested in being populated).

If it is, its kind of messy. The basic gist is that you go by field poc. 
If two complementary field pairs have the same POC, first in decoding 
order is output first except when dealing with complementary reference 
field pairs, in which case they are output together.

	-Jeff