[Ffmpeg-devel] Re: [PATCH] DVCPRO50 support

Roman Shaposhnick rvs
Fri Mar 3 01:58:33 CET 2006

On Fri, Mar 03, 2006 at 01:05:46AM +0100, Baptiste COUDURIER wrote:
> Roman Shaposhnick wrote:
> > On Wed, Mar 01, 2006 at 08:08:56PM -0500, Dan Maas wrote:
> > 
> >>Hi Roman - Here is the big patch for DVCPRO50 support. Please look it
> >>over and get back to me with any comments. 
> > 
> > 
> > Hi Dan -- thanks a lot for submitting it. I'll try to take a look
> > at it today.
> > 
> > 
> >>This adds support for both NTSC and PAL with 4:2:2 sampling at 50
> >>Mbps, according to SMPTE 314M. The 50 Mbps mode is turned on when you
> >>compress or decompress 4:2:2 video (PIX_FMT_YUV422P). Otherwise it
> >>operates at 25 Mbps just like before.
> > 
> > 
> >   Seems like a reasonable choice.
> Sorry to disturb the discussion, but why not adding a new video codec ?

  As far as the codec is concerned these two are quite similar, so creating
  CODEC_ID_DVCPRO50 would be like having a separate codec id for a MPEG2 
  streams carrying HD broadcasts. Now, DVCPRO HD is substantially different 
  and will require its personal id.

> IMHO It would simpler to handle wrapping in
> different containers (thinking about MOV), which must be different.

  Do you have any particular concern in mind ?

> I tested the patch and it perfectly plays in Quicktime Player and Final
> Cut, in DV file format. Talking about MOV, setting fourcc to 'dv5p'
> makes it working.

  Well, this seems to be as simple as just adding a couple of fourcc values
  to all the right places. DV decoder will be able to deal with both
  flavors of DV regardless of whether demuxer is there or not. And we don't
  really handle the sort of AVI-type1 DV anyway.

> Just noticed one thing. When you probe the stream, pix_fmt is not set
> correctly, displays yuv420p while obvioulsy pix_fmt is yuv422p.

  Our first bug report for DVCPRO50 ;-)


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