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

[Stefano Sabatini]

On date Wednesday 2011-04-06 23:35:57 +0100, Mark Himsley encoded:
> On 05/04/11 23:32, Stefano Sabatini wrote:
> >On date Tuesday 2011-04-05 22:52:01 +0100, Mark Himsley encoded:
> >>On 03/04/2011 22:21, Mark Himsley wrote:
> >>>On 03/04/2011 15:21, Stefano Sabatini wrote:
> >>>>On date Friday 2011-04-01 19:31:41 +0100, Mark Himsley encoded:
> >>>>>On 31/03/11 15:15, Stefano Sabatini wrote:
> >>>>>>On date Thursday 2011-03-31 08:47:38 +0100, Mark Himsley encoded:
> >>>>>>>Second version of this filter. Renamed and updated from the
> >>>>>>>suggestions given for the first version.
> >>
> >>[...]
> >>
> >>>>>+    /** discover the bytes per pixel for each plane */
> >>>>>+    if (is_packed) {
> >>>>>+        fieldorder->line_step[0] = av_get_bits_per_pixel(&av_pix_fmt_descriptors[inlink->format])>>3;
> >>>>>+    } else {
> >>
> >>Sorry - I've also noticed that getting the bytes per pixel with
> >>av_get_bits_per_pixel(&av_pix_fmt_descriptors[inlink->format])>>3 is not
> >>accurate for the rgb444 or rgb555 formats. I'm just contemplating the
> >>best thing to do, which has delayed me a little. I'll be back with an
> >>updated patch soon.

> >As I suggested, av_image_fill_max_pixsteps() may help. And if we want
> >to be sure not to break the filters when some new format is added,
> >just enumerates the working filters in query_formats().
                               ^^^^^^^

Ehm it was pixel formats.

> Yes. I you do have a point.
> 
> But, should I just be using av_image_get_linesize() once per plane
> to retrieve the number of bytes to memcopy?

Yes, you can do it just one time during initialization and cache the
value in the filter context.
-- 
FFmpeg = Foolish and Fanciful Marvellous Plastic Elected Goblin