[FFmpeg-devel] lavfi state of affairs

[Michael Niedermayer]

On Fri, Feb 06, 2009 at 10:37:51AM +0100, Michael Niedermayer wrote:
> kOn Thu, Feb 05, 2009 at 07:55:24PM -0800, Baptiste Coudurier wrote:
> > On 2/5/2009 7:15 PM, Michael Niedermayer wrote:
> > > On Thu, Feb 05, 2009 at 05:26:33PM -0800, Baptiste Coudurier wrote:
[...]
> > >>>> Besides does this mean that gif encoder is right to use PAL8,
> > >>>> and libswscale is supporting PAL8 but misuse BGR8 ?
> > >>> i dont understand what you mean
> > >> You said that libswscale supports PAL8 however it isSupportedOut
> > >> does not accept PIX_FMT_PAL8.
> > >>
> > >> Can we refer in terms of PIX_FMT_* please ?
> > >>
> > >> I don't understand anything of what you explain, yet Im dev, how
> > >> can you expect a user to understand ?
> > >
> > > There is a 8 bit paletted format (PIX_FMT_PAL8) it can have an
> > > arbitrary palette. There is a 8 bit paletted format (PIX_FMT_BGR8)
> > > that has a single systematic 884 palette. There is a 8 bit paletted
> > > format (PIX_FMT_XXX) that has a single systematic 666 palette.
> > >
> > > imgconvert supports outputting PIX_FMT_XXX (while using the enum
> > > value of PIX_FMT_PAL8 for it incorrectly due to lack of a
> > > PIX_FMT_XXX) swscale supports outputting PIX_FMT_BGR8 neither support
> > > arbitrary palettes nor the others systematic palette if they support
> > > PIX_FMT_PAL8 is a matter of philosophy you could say both do because
> > > each support a systematic paletted 8bit format or you could say
> > > neither does because neither supports an arbitrary palette
> > >
> > >
> > >> Libav* user looks and see: "OH gif uses PAL8", then he setups
> > >> libswscale and libswscale chokes saying PAL8 unsupported. What does
> > >> he do ? He will use imgconvert !
> > >
> > > iam not going to fix imgconvert which would mean make it reject PAL8
> > > add a RGB666 and make it accept that instead and then add RGB666,
> > > PAL8, BGR8 and RGB8 to gif
> > >
> > > i will simply ignore imgconvert and fix gif+swscale i hope this will
> > > end this discussion because honestly iam sick of it.
> > 
> > I'm sad to hear that finally explaining non obvious parts makes you 
> > being sick.
> 
> what makes me sick is that you talk about bugs in gif.c and utils.c as
> if they where bugs in swscale.
> it works with imgconvert because it has matching bugs that cancel the
> effect of bugs in utils.c
> but let us rather fix the issues instead of continuing this discussion

as promissed, ive fixed gif + swscale, also note that not a single byte
in libswscale/* was changed all the issues where in imgconvert* utils.c
and gif.c

also ive added 2 lines clarifying the 8bpp formats in relation to palettes

and gifs now look vastly better than before and you can also make grayscale
and 16color gifs as a sideeffect

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I am the wisest man alive, for I know one thing, and that is that I know
nothing. -- Socrates
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20090206/2498eae9/attachment.pgp>