[FFmpeg-devel] [PATCH] Implement pixdesc.h:write_line()

[Stefano Sabatini]

On date Thursday 2009-04-02 22:40:50 +0200, Michael Niedermayer encoded:
> On Thu, Apr 02, 2009 at 09:15:41PM +0200, Stefano Sabatini wrote:
> > On date Thursday 2009-04-02 01:27:18 +0200, Michael Niedermayer encoded:
> > > On Thu, Apr 02, 2009 at 12:02:34AM +0200, Stefano Sabatini wrote:
> > > > Hi all.
> > > > 
> > > > Formats when possible have been tested with the vf_pixdesc_test
> > > > filter, included the monowhite and monoblack formats, with something
> > > > like:
> > > > 
> > > > ffplay in.avi -vfilters "format=gray,pixdesc_test"
> > > > 
> > > > Some formats cannot be tested this way, for example all the formats
> > > > not supported as output by sws, anyway I think that it's quite safe to
> > > > apply it anyway.
> > > > 
> > > > Many interesting problems remains opened, for example:
> > > > 
> > > > * How are we supposed to deal with HW accelerated pixel formats?  Are
> > > >   we supposed to add an entry in the pixdescs arrays for each of them?
> > > > 
> > > 
> > > > * It's not clear which should be the interaction between lsws and
> > > >   the pixdescs.
> > > > 
> > > >   Currently lsws doesn't depend on lavc, since the pixfmt descriptors
> > > >   may and should be used in libsws to avoid code duplication
> > > >   (e.g. sws_format_name()), we may either add lavc to the lsws
> > > >   dependancies *or* move all the pixdesc stuff to lavu.
> > > 
> > > why would lavc need the pixdescs ? if it doesnt they could be moved to sws
> > 
> > To retain in lavc all the functionality currently implemented in
> > imgconvert, which currently uses pixfmtinfo which we're trying to
> > dump and substitute with pixdescs.
> > 
> > Alternatively we could make lavc depend on lsws, but somehow doesn't
> > sound like a great idea...
> >  
> > > also let me repeat, 1 patch per mail please!
> > > if we ever implement the suggested patch tracker all mails with multiple
> > > patches will "disapear".
> > > its easy to search subjs for [PATCH], easy to search for looks ok and
> > > applied but this breaks down if there are multiple patches per mail
> > > besides its alot harder for me to keep track and i suspect also for
> > > others independant of any fancy tools
> > > also its hard to reply to a subset of patches in this mess mails.
> > 
> > OK sorry, the patches attached were meant to help to actually test the
> > write_line() patch. I'll repost them to separate threads.
> > 
> > Patch updated with the suggestions by Ben.
> [...]
> > +        while (w--) {
> > +            int val = *src++;
> > +            put_bits(&pb, depth, val);
> > +            if (step - depth)
> 
> > +                skip_put_bits(&pb, step - depth);
> 
> i suspect this will randomize the bits

That's why I added the if (step - depth) check (yes without that it
was broken).
Am I missing something?

Regards.
-- 
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