[MPlayer-dev-eng] Make dvd-compatible mpeg's and keyint (gop size)

Rich Felker dalias at aerifal.cx
Thu Sep 29 17:04:38 CEST 2005


On Thu, Sep 29, 2005 at 03:12:09PM +0600, byavl wrote:
> Rich Felker wrote:
> >On Thu, Sep 29, 2005 at 06:49:50AM +0300, Oded Shimon wrote:
> >
> >>On Thu, Sep 29, 2005 at 09:36:21AM +0600, byavl wrote:
> >>
> >>>Hi!
> >>>Can anyone to describe why default for the keyint option
> >>>set as 250 ?
> >>>Many of a DVD author applications to require the strong dvd compliance
> >>>for GOP size. 30 frames (for PAL) and not more.
> >
> >
> >AFAIK the limit is 18 for NTSC and 15 for PAL for NTSC-FILM. Never
> >heard of 30..
> of course I meant 15. see example.
> >
> >>>Anyone can to change this default ?
> >
> >No, like Oded said...
> >
> >>lavc encoder has most settings default for making mpeg-4 streams, for dvd 
> >>compliance you need way more options than just changing keyint, you also 
> >>need to change some vrc settings and a bunch of other stuff... I don't 
> >>think it's worth changing the default just for this tiny option...
> >
> >Exactly.
> 
> What exactly ? mpeg-4 has smart defaults, but what dvd ?
> Is it good practic when I must to explore all options
> because your defaults is out of standarts ?
> You suggest to specify all options. Say no if I say it is stupid!

Then make an option to set all the restrictions needed for DVD and
send us a patch!!

> Default means values that decrease preparing time and
> save from mistakes.

Default is not possible. The options are the same for each codec; they
can't magically have different defaults depending on which codec
you've selected. This has all kinds of issues that will be broken!

Also, mpeg2 is not dvd-only, so there's no legitimate reason to
restrict to dvd parameters just because the user has selected mpeg2.

> Manual has no intelligible description
> how to do mpeg2 and DVD compliance materials.

Again submit a patch!

Your posts here have been totally off-topic. You're whining about user
issues and posting to the developer list. Even when you sent a (bad)
"patch" it wasn't a unified diff but some comments in the message body
about how to make the change.

If you have a feature request, you have two options. Post it on -users
list or the bug tracker, or alternatively write a proper patch to
implement it yourself and submit that to -dev-eng list. I would
suggest looking at the way ffmpeg does its -target option for a good
idea of what we would accept.

Rich






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