[Ffmpeg-devel] [PATCH] mov dnxhd muxing

Robert Swain robert.swain
Thu Mar 22 14:44:33 CET 2007


Hey,

On 22/03/07, Baptiste Coudurier <baptiste.coudurier at smartjog.com> wrote:
> Michael Niedermayer wrote:
> > On Wed, Mar 21, 2007 at 02:49:14PM +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
>
> Humm I would prefer not, and I would like to remove those fancy flavors
> of mp4 muxers, Im looking for a generic way to handle specific atoms
> required for ipod/psp. 3g2 muxer is code duplication and it only change
> brand of ftyp atom, psp only adds a few atoms, maybe a "target" or
> "flavor" field in AVFormatContext, then a table of flavors in muxers ?
> That should provide also some kind of "target" support, we could provide
> some AVOption tables to be used.

I'm not totally certain but I think the special PSP atoms are no
longer required. I think I read that they removed the requirement in a
particular firmware revision so the PSP stuff can probably be removed
entirely anyway. I've tested generic files on official firmwares and
they work as long as they abide by the usual stream constraints for
the PSP.

Rob




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