[FFmpeg-devel] lavfi noise generator

Stefano Sabatini stefano.sabatini-lala
Thu Jan 15 23:58:59 CET 2009


On date Thursday 2009-01-15 21:53:06 +0100, Vitor Sessak encoded:
> Stefano Sabatini wrote:
> > On date Saturday 2009-01-03 18:09:49 +0100, Stefano Sabatini encoded:
> >> On date Monday 2008-12-29 13:45:23 +0100, Michael Niedermayer encoded:
> >>> On Mon, Dec 29, 2008 at 11:39:30AM +0100, Stefano Sabatini wrote:
> >>>> On date Monday 2008-12-29 00:52:18 +0100, Michael Niedermayer encoded:
> >>>>> On Mon, Dec 29, 2008 at 12:25:02AM +0100, Stefano Sabatini wrote:
> >>>>>> Hi all,
> >>>>>>
> >>>>>> no Michael I'm not posting it for you or others to review it, I'm just
> >>>>> no but i reject it anyway
> >>>>> your code is crap, sorry
> >>>>>
> >>>>> People didnt want to port libmpcodecs when i suggested it, i dont mind
> >>>>> this at all, libmpcodecs has its serious issues but this does not mean i
> >>>>> will accept code that is inferrior than it.
> >>>>>
> >>>>> vf_noise.c should be MUCH faster than your code.
> >>> [...]
> >>>> As for the speed concerns, I see two major issues to be addressed, the
> >>>> use of the av_random() for setting every single byte, ideally we
> >>>> should set the whole buffer for example reading from /dev/urandom but
> >>>> this would not be portable, and the av_picture_copy() can be avoided
> >>>> using properly the permissions system and passing a picture reference.
> >>> did you read vf_noise.c ?
> >> What about a noise module in libavutil (based on your vf_noise.c)?
> >>
> >> For example it may be shared between a noise source and filter, also I
> >> think those routines may be useful also in other places.
> > 
> > In attachment my idea, yes it still needs some rework (mainly I need
> > to understand better the code of noise.[ch]), I basically just did
> > some monkey translation from your code.
> 
> Just one comment:
> 
> > static int query_formats(AVFilterContext *ctx)
> > {
> >     /* all YUV planar formats */
> >     avfilter_set_common_formats(ctx,
> >                                 avfilter_make_format_list(10,
> >                                                           PIX_FMT_YUV444P,  PIX_FMT_YUV422P,  PIX_FMT_YUV420P,
> >                                                           PIX_FMT_YUV411P,  PIX_FMT_YUV410P,
> >                                                           PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
> >                                                           PIX_FMT_YUV440P,  PIX_FMT_YUVJ440P)
> >         );
> 
> Can't the filter be simply modified to also accept most RGB formats?

Absolutely, that will be for the next round.

Regards.
-- 
FFmpeg = Frightening and Frenzy Mysterious Puritan Erotic Gymnast




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