[Ffmpeg-devel] [PATCH] mov dnxhd muxing

Michael Niedermayer michaelni
Fri Mar 23 20:10:17 CET 2007


Hi

On Fri, Mar 23, 2007 at 12:40:49PM +0100, Baptiste Coudurier wrote:
> Michael Niedermayer wrote:
> > Hi
> > 
> > On Fri, Mar 23, 2007 at 10:47:26AM +0100, Baptiste Coudurier wrote:
> >> Michael Niedermayer wrote:
> >>> 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.
> > 
> > have you tried "dv5p" tag with avid specific atoms? does fcp play that?
> 
> Those atoms are unneeded with "dv5p", it would be stupid to write them.

well we will not redesign the API because of your philosophical beliefs
if always writing these atoms for dv in mov solves the problem then so 
should they be always written alternatively theres always the option
of no dv in mov support or 2 muxers like its done with psp ...


> 
> >>> how does fcp & avid play dv from a camera? if theres no common format both
> >>> support?
> >> Quicktime has no dv50 native codec, while it has dv25.
> >>
> >> Now I need to ingest my mpeg2 422 into avid and fcp so I transcode to
> >> dv50 in mov with ffmpeg, and that does not work with avid atm, avid file
> >> is missing mandatory atoms to be decoded, I want to add that feature.
> > 
> > i dont belive that there is no other codec and container which can be
> > used to import video from ffmpeg into avid, if there where none, avid
> > would be unuseable ...
> > 
> > 
> > heres a list if solutions in order of preferance (more prefered first)
> > * dont support muxing DV in MOV
> 
> Not an option, it works perfectly.
> 
> > * dont support AVID specific hacks for DV in MOV
> 
> Not an option, I don't see any good reason to not support muxing files
> for AVID systems.
> 
> > * support AVID specific hacks in MOV through a dummy muxer like for psp
> 
> That is an ugly hack.
> 
> According to new policy, can you please supply me a full svn dump ?
> Thanks.

i would if i had access to it, please ask
root at mphq or 
mphq Ad lists d0T suug point ch

and feel free to CC ffmpeg-dev

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

No human being will ever know the Truth, for even if they happen to say it
by chance, they would not even known they had done so. -- Xenophanes
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