On 8/1/17, Tobias Rapp <t.r...@noa-archive.com> wrote: > On 01.08.2017 15:31, Paul B Mahol wrote: >> On 8/1/17, Tobias Rapp <t.r...@noa-archive.com> wrote: >>> On 01.08.2017 13:03, Paul B Mahol wrote: >>>> Signed-off-by: Paul B Mahol <one...@gmail.com> >>>> --- >>>> doc/filters.texi | 13 ++ >>>> libavfilter/Makefile | 1 + >>>> libavfilter/allfilters.c | 1 + >>>> libavfilter/vf_premultiply.c | 307 >>>> ++++++++++++++++++++++++++++++++++++------- >>>> 4 files changed, 277 insertions(+), 45 deletions(-) >>>> >>>> diff --git a/doc/filters.texi b/doc/filters.texi >>>> index 4089135..a50696a 100644 >>>> --- a/doc/filters.texi >>>> +++ b/doc/filters.texi >>>> @@ -14532,6 +14532,19 @@ ffmpeg -i INPUT -vf trim=duration=1 >>>> >>>> @end itemize >>>> >>>> +@section unpremultiply >>>> +Apply alpha unpremultiply effect to input video stream using first >>>> plane >>>> +of second stream as alpha. >>>> + >>>> +Both streams must have same dimensions and same pixel format. >>>> + >>>> +The filter accepts the following option: >>>> + >>>> +@table @option >>>> +@item planes >>>> +Set which planes will be processed, unprocessed planes will be copied. >>>> +By default value 0xf, all planes will be processed. >>>> +@end table >>> >>> IMHO using a flags-like string "planes=rgb" would be more user-friendly >>> than a bitmask. At least the documentation should tell which bit refers >>> to what channel. >> >> It is directly related to pixel format. > > I'm just wondering whether I can apply the logic of > AVPixFmtDescriptor.comp to the planes bitmask or not: > > /** > * Parameters that describe how pixels are packed. > * If the format has 1 or 2 components, then luma is 0. > * If the format has 3 or 4 components: > * if the RGB flag is set then 0 is red, 1 is green and 2 is blue; > * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V. > * > * If present, the Alpha channel is always the last component. > */
I mainly did it bitmask way because of additional code needed to handle cases when there is no r/g/b but y/u/v planes and user supplied r/g/b only. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
