[FFmpeg-devel] [PATCH] add top video filter

[Víctor Paesa]

Hi,

On Mon, Mar 28, 2011 at 15:47, Mark Himsley wrote:
> Dear developers,
>
> Converting to and from interlaced PAL DV files, with their
> bottom-field-first interlace field order, can be a pain. Converting tff
> files to DV results in tff DV files, which are hard to work with in editing
> software.
>
> The attached filter can:
>
> Convert field order by either moving all of the lines in the picture up by 1
> line (bff to tff conversion) or down by 1 line (tff to bff conversion). The
> remaining line, the bottom line in bff to tff transforms or the top line in
> tff to bff transforms, is filled by copying the closest line in that field.
>
> Previous to this filter I have used a filter chain like this to do bff to
> tff conversion.
>
> format=yuv422p,crop=720:575:0:1,pad=720:576:0:0:black
>
> but that chain does not fill the remaining line.

> +It requires one parameter: @var{tff}
> +
> + at var{tff} specifies the required field order that the input interlaced
> +video will be transformed to, accepts one of the following values:

"video will be transformed to, and it accepts one of the following values:"

> +
> + at table @option
> + at item 0
> +output bottom field first
> + at item 1
> +output top field first
> + at end table
> +
> +There is no default.
+
+Transformation is done by shifting the picture content up or down
+by one line, and filling the remaining line with appropriate picture content.
+This method is consistant with most broadcast field order converters.

consistent

+
+This filter is very useful when converting to or from PAL DV material,
+which is bottom field first.

Regards,
Víctor