[Ffmpeg-devel] [PATCH] mov dnxhd muxing

[Michael Niedermayer]

Hi

On Fri, Mar 23, 2007 at 02:54:20AM +0100, Baptiste Coudurier wrote:
> Michael Niedermayer wrote:
> > Hi
> > 
> > On Fri, Mar 23, 2007 at 02:05:50AM +0100, Baptiste Coudurier wrote:
> >> Michael Niedermayer wrote:
> >>> Hi
> >>>
> >>> On Fri, Mar 23, 2007 at 01:05:20AM +0100, Baptiste Coudurier wrote:
> >>>> Michael Niedermayer wrote:
> >>>>> Hi
> >>>>>
> >>>>> On Thu, Mar 22, 2007 at 11:04:05PM +0100, Baptiste Coudurier wrote:
> >>>>>> Hi
> >>>>>>
> >>>>>> Michael Niedermayer wrote:
> >>>>>>> Hi
> >>>>>>>
> >>>>>>> On Thu, Mar 22, 2007 at 06:41:00PM +0100, Baptiste Coudurier wrote:
> >>>>>>>> Hi
> >>>>>>>>
> >>>>>>>> Michael Niedermayer wrote:
> >>>>>>>>> Hi
> >>>>>>>>>
> >>>>>>>>> On Thu, Mar 22, 2007 at 01:53:48PM +0100, Baptiste Coudurier wrote:
> >>>>>>>>> [...]
> >>>>>>>>>>>> Also, avid codecs need those specific mov atoms for some codecs ffmpeg
> >>>>>>>>>>>> already supports, what would be the good way to write them ?
> >>>>>>>>>>>>
> >>>>>>>>>>>> Example: you can mux dv into mov using "AVdv" tag, then avid codecs will
> >>>>>>>>>>>> decode stream perfectly if those atoms are present, though quicktime
> >>>>>>>>>>>> wont decode it by default.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Quicktime has a native decoder for dv25 so use native one, but for dv50,
> >>>>>>>>>>>>   there is no decoder. We can use Final cut one, which use his own
> >>>>>>>>>>>> codec/own tag but only useable when fcp is installed, or Avid ones which
> >>>>>>>>>>>> are freely available.
> >>>>>>>>>>>>
> >>>>>>>>>>>> So what muxing by default, and how to switch ? codec_tag ("stsd" tag) is
> >>>>>>>>>>>> a solution, but people will have to know which tag to use.
> >>>>>>>>>>> i dont think codec_tag should be (mis)used for this, but rather a new muxer
> >>>>>>>>>>> similar to the one for psp should be added to movenc.c
> >>>>>>>> Can you explain why you think that is "misusing" ? Remember that
> >>>>>>> because the value of codec_tag does not depend on the existence of these
> >>>>>>> specific atoms, a specific codec_tag also doesnt require a specific
> >>>>>>> set of these atoms just try mp4v and psp vs. mp4
> >>>>>> I am talking about existence of these atoms because of the value of
> >>>>>> codec_tag, and that is correct.
> >>>>>>
> >>>>>>>> quicktime pass whole stsd atom to decoders, and those atoms are
> >>>>>>>> contained IN stsd atom, so you cannot decorelate them.
> >>>>>>> well you dont pass the whole atoms and you didnt propose to pass them
> >>>>>>> so thats unrelated ...
> >>>>>> existence of these specific atoms depends on codec_tag.
> >>>>> huh? movenc.c does not contain code which writes them depending on codec_tag
> >>>> huh, that's what Im willing to do and fighting for, you are against it,
> >>>> Im proposing another solution, you are against it, you propose another
> >>>> muxer, Im against it, I think we are having a fair discussion here.
> >>>> I want to write those atoms if tag is AVdn or AVdv or ....
> >>> why not write them if codec_id==DVVIDEO ?
> >> I asked that in the first mail :(
> > 
> > you asked about using codec_tag not codec_id theres a difference
> > codec_tag is wrong codec_id is fine
> > but its not clear yet to me if a test based on codec_id is possible
> > its not clear from what you write 
> 
> Damn, that is not possible. So since my opinion does have any weigth, I
> would like you to give me a solution to be able to create two files with
> DVVIDEO as codec_id, pix_fmt as PIX_FMT_422P and 720x576 res, one will
> be correctly played by avid codecs and one by Final cut pro. For avid
> they must have "AVdv" tag and avid specific atoms, for Final Cut they
> must have "dv5p" tag.

how does fcp & avid play dv from a camera? if theres no common format both
support?

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

I have often repented speaking, but never of holding my tongue.
-- Xenocrates
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