[MPlayer-users] how to set mpi->fields?

[Rich Felker]

On Fri, Jan 25, 2008 at 03:20:11PM +0800, boku wrote:
> Dear all,
>      I'm writing the wrapper, vd_xxx.c. And have some questions about
> mpi->fields. It can have 4 kinds of different
> #define MP_IMGFIELD_ORDERED 0x01
> #define MP_IMGFIELD_TOP_FIRST 0x02
> #define MP_IMGFIELD_REPEAT_FIRST 0x04
> #define MP_IMGFIELD_TOP 0x08
> #define MP_IMGFIELD_BOTTOM 0x10
> #define MP_IMGFIELD_INTERLACED 0x20
> 
> I don't know which one I should set if the decoder only decodes frame (no
> interlaced).

Set it to 0, the default. Unless bit 1 (ORDERED) is set, there's no
order relation between the fields.

> And in interlace mode, one mpi has only one interlaced picture, right?
> The mplayer uses this field to check the picture is top or bottom?

Normally interlaced has 2 fields interleaved together on alternating
lines. In theory the fields could be processed separately using the
TOP and BOTTOM bits, but there's no code anywhere to support that
well. Actually interlacing pretty much isn't supported to begin with
except keeping track of the fact that the decoder said the picture was
interlaced, and in some inverse-telecine filters.

Rich