[Ffmpeg-devel] Closing all GOPs.

[Michael Niedermayer]

Hi

On Saturday 16 July 2005 21:29, Guillaume POIRIER wrote:
> 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?

yes

[...]
-- 
Michael