[Ffmpeg-devel] Closing all GOPs.

[Guillaume POIRIER]

Hi,

On 7/16/05, Michael Niedermayer <michaelni at gmx.at> wrote:
> Hi
> 
> On Saturday 16 July 2005 20:10, Guillaume POIRIER wrote:
> > Hi,
> >
> > On 7/16/05, M?ns Rullg?rd <mru at inprovide.com> wrote:
> > > Julio C?sar Carrascal said:
> > > > Hi. I'm trying to create a compliant video for a DVD with mencoder.
> > > > Right now most DVD creation programs (Nero Vision, Sony DVD Architect
> > > > and DVD-Lab PRO) complaint because the GOPs aren't closed in the file
> > > > and try to re-encode it. I asked in the mencoder-users list and they
> > > > thold me that the feature wasn't implemented and I should ask here.
> > > >
> > > > My question would be: Is "cgop" going to be implemented any time soon?
> > > > If so, any idea when will a release be available?
> > >
> > > It's been there for a year or so, at least.  IIRC, CODEC_FLAG_CLOSED_GOP
> > > or something similar is the internal name.  I'm sure someone else can
> > > tell you how to have mencoder use it.
> >
> > It should be already implemented in MEncoder. ve_lavc.c:612 has this:
> >
> > #ifdef CODEC_FLAG_CLOSED_GOP
> >     lavc_venc_context->flags|= lavc_param_closed_gop;
> > #endif
> >
> > What I'm not too sure though is if CODEC_FLAG_CLOSED_GOP is always
> > defined so this part of the code get compiled or not. MPlayer's doc
> > says that closed GOP is not implemented yet.
> 
> the docs are wrong, cgop does work as long as scene change detection is
> disabled (-sc_threshold 1000000000 for example will do that in ffmpeg)

Ok, I guess it's not something you want to do (because the scene
change detection is supposed to code the scene change with an I frame,
which is seekable, and is wiser instead of coding it with a P frame,
and of putting I frames only every keyint) unless you really need
closed GOPs. Am I right?

Guillaume
-- 
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