[FFmpeg-devel] [RFC] h264 avoid starting decode on a non top?field

[Michael Niedermayer]

On Sat, Nov 12, 2011 at 07:12:44PM +0000, Joakim Plate wrote:
> Carl Eugen Hoyos <cehoyos <at> ag.or.at> writes:
> 
> > 
> > madshi <madshi <at> gmail.com> writes:
> > 
> > > This sounds like a similar problem to:
> > > 
> > > https://ffmpeg.org/trac/ffmpeg/ticket/354
> > 
> > Yes, it is.
> > 
> > Carl Eugen
> > 
> 
> 
> Soo0... anybody have h264 specs and can check what signals the first field of a 
> field pair?

sure, here are some related quotes:


3.34 complementary field pair: A collective term for a complementary reference field pair or a complementary
     non-reference field pair.
3.35 complementary non-reference field pair: Two non-reference fields that are in consecutive access units in
     decoding order as two coded fields of opposite parity and share the same value of the frame_num syntax
     element, where the first field is not already a paired field.
3.36 complementary reference field pair: Two reference fields that are in consecutive access units in decoding
     order as two coded fields and share the same value of the frame_num syntax element, where the second field
     in decoding order is not an IDR picture and does not include a memory_management_control_operation
     syntax element equal to 5.
...
3.91 non-paired field: A collective term for a non-paired reference field or a non-paired non-reference field.
3.92 non-paired non-reference field: A decoded non-reference field that is not part of a complementary
     non-reference field pair.
3.93 non-paired reference field: A decoded reference field that is not part of a complementary reference field
     pair.
...
[lots of blah]
    NOTE 6 ­ The above constraints specify that when both fields of a frame or a complementary field pair are marked as "used for
    reference" after processing all memory_management_control_operation commands of the decoded reference picture marking
    syntax structure, either both fields must be marked as "used for short-term reference" or both fields must be marked as "used for
    long-term reference". When both fields are marked as "used for long-term reference", the same long-term frame index must be
    assigned to both fields.

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I have often repented speaking, but never of holding my tongue.
-- Xenocrates
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20111112/38d6fcf6/attachment.asc>