[FFmpeg-devel] XVMC Deathmatch

[Ivan Kalvachev]

On 2/15/09, Diego Biurrun <diego at biurrun.de> wrote:
> On Sun, Feb 15, 2009 at 01:01:36AM +0100, Diego Biurrun wrote:
>> On Sun, Feb 15, 2009 at 01:56:49AM +0200, Ivan Kalvachev wrote:
>> > On 2/15/09, Diego Biurrun <diego at biurrun.de> wrote:
>> > > On Sun, Feb 15, 2009 at 12:29:18AM +0100, Michael Niedermayer wrote:
>> > >> On Sat, Feb 14, 2009 at 11:40:35PM +0100, Diego Biurrun wrote:
>> > >> > On Sat, Feb 14, 2009 at 11:30:02PM +0100, Michael Niedermayer
>> > >> > wrote:
>> > >> > > On Sat, Feb 14, 2009 at 10:38:39PM +0100, Diego Biurrun wrote:
>> > >> > > > On Sat, Feb 14, 2009 at 04:53:01PM +0100, Michael Niedermayer
>> > >> > > > wrote:
>> > >> > > > >
>> > >> > > > > >    //these are not changed by the decoder!
>> > >> > > > > >    int  magic;
>> > >> > > > >
>> > >> > > > > 3 points
>> > >> > > > > find and get rid of or rename fields to "ununsed123" all
>> > >> > > > > unused
>> > >> > > > > fields in this
>> > >> > > > > struct, dont break ABI!
>> > >> > > >
>> > >> > > > All fields are used either in FFmpeg or MPlayer.
>> > >> > > >
>> > >> > > > The following are unused in FFmpeg:
>> > >> > > >
>> > >> > > >   int             mc_type;
>> > >> > > >   int             chroma_format;
>> > >> > > >   unsigned int    display_flags;
>> > >> > > >   int             state;
>> > >> > > >   void*           p_osd_target_surface_render;
>> > >> > > >
>> > >> > > > But they are all used in libvo/vo_xvmc.c in MPlayer as can be
>> > >> > > > seen
>> > >> > > > by
>> > >> > > > trying to compile against an xvmc.h without those fields:
>> > >> > > >
>> > >> > > > libvo/vo_xvmc.c: In function 'xvmc_draw_image':
>> > >> > > > libvo/vo_xvmc.c:378: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'state'
>> > >> > > > libvo/vo_xvmc.c: In function 'config':
>> > >> > > > libvo/vo_xvmc.c:536: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'mc_type'
>> > >> > > > libvo/vo_xvmc.c:538: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'chroma_format'
>> > >> > > > libvo/vo_xvmc.c: In function 'draw_osd':
>> > >> > > > libvo/vo_xvmc.c:899: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'display_flags'
>> > >> > > > libvo/vo_xvmc.c:899: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'display_flags'
>> > >> > > > libvo/vo_xvmc.c:902: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'state'
>> > >> > > > libvo/vo_xvmc.c:903: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'state'
>> > >> > > > libvo/vo_xvmc.c:904: error: 'struct xvmc_render_state' has no
>> > >> > > > member
>> > >> > > > named 'p_osd_target_surface_render'
>> > >> > > > [...]
>> > >> > > >
>> > >> > > > Does research give points? :)
>> > >> > >
>> > >> > > no, you have to remove or rename these fields to unused* to get
>> > >> > > the
>> > >> > > points.
>> > >> >
>> > >> > Well, I did do
>> > >> >
>> > >> >    int             mc_type;
>> > >> >
>> > >> > -->
>> > >> >
>> > >> >    int             unused1;
>> > >> >
>> > >> > and FFmpeg compiles fine afterwards, but when I put that xvmc.h in
>> > >> > my
>> > >> > MPlayer tree, I get the above compilation failure.
>> > >> >
>> > >> > Thus my conclusion is that the field is not, as you claim, unused.
>> > >> > Am I missing something?
>> > >> >
>> > >> > > am i allowed to give tips on how to solve such things?
>> > >> >
>> > >> > This will likely result in more fixes :)
>> > >>
>> > >> well
>> > >> first as was said the header was not public thus no rename in the
>> > >> header
>> > >> really could break an external APP, removial of a field of course
>> > >> could
>> > >> so renaming these to unused123 and placing them under #if
>> > >> no_major_bump_yet
>> > >> should not break anything (in theory)
>> > >
>> > > I had all the fields I mentioned above under
>> > >
>> > > #if LIBAVCODEC_VERSION_MAJOR < 53
>> > >
>> > >> yes it means mplayer has to be updated before the next major bump and
>> > >> before it could use our installed header instead of its private copy
>> > >>
>> > >> but thats mplayers problem to say it harshly ...
>> > >
>> > > Well...
>> > > Ivan designed this incestuously.  It's kind of hard to tell if this is
>> > > a
>> > > public or a private header...
>> >
>> > Well, don't tell me I didn't had reasons to hold your
>> > plans on making it public header.
>>
>> You held that plan back for many years.  Without this deathmatch, you
>> would not have made those changes to MPlayer.
>>
>> > > I suggest that we assume it is becoming a public header just now and
>> > > thus
>> > > now that Ivan updated MPlayer to not use them anymore, the following
>> > > two
>> > > fields could be safely be removed:
>> > >
>> > >    int mc_type;
>> > >    int chroma_format;
>> > >
>> > > OK to remove them?
>> >
>> > You were the one who insisted on installing it.
>> > Deal with the consequences.
>>
>> I take that as a "I don't care", which I will now interpret to mean I
>> have a free ticket to go ahead.
>
> Note to Michael: I know this breaks ABI and API.  I'm operating under the
> assumption that the API is still in flux and the only user is MPlayer,
> which has already been updated.
>
> So don't go subtracting points from me :)

Michael,
Is breaking ABI OK for you.
I can make some general changes if this is so!