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

Roman Shaposhnick rvs
Mon Mar 6 10:32:47 CET 2006


it's applied. There's still a small glitch w.r.t. container formats not
setting pix_fmt correctly for decoder and a couple of other small things
I would like to tweak during the week. But otherwise -- it went into
a CVS pretty much unchanged. 


P.S. The main trick was to review your changes with 'diff -b'
which cuts down 80% of the indentation related changes ;-)

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. 
> 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.
> 4 audio channels (in 2 stereo pairs) are supported in 50 Mbps mode.
> The only thing that I know is missing is a regression test for 50 Mbps
> mode. I don't know how to add one, so please help!
> Other minor changes:
> I changed the NTSC audio sample pattern to agree with SMPTE 314M.
> The spec only allows
> 1600,1602,1602,1602,1602
> not
> 1602,1601,1602,1601,1602.
> I changed dv_anchor to be statically allocated, which seems simpler
> and more efficient.
> I increased a few of the hard-coded array sizes to handle 50 Mbps.
> I moved large buffers to the end of struct RawDVContext and
> DVMuxContext. I think on most CPU architectures it is more efficient
> not to have small struct members at very large offsets.
> I made dvvideo_encode_frame() fill in just enough of the header so
> that dv_frame_profile() will recognize the correct format. This is
> necessary to correctly decode frames that haven't been passed through
> the dvvideo avformat driver. (long term, the DV header filling should
> probably be moved into the avcodec, since it is necessary to have
> complete headers for "wrapped" formats like DV-within-Quicktime).
> I added a 'DVprofile *sys' member to DVDemuxContext, which makes the
> demuxing code a little cleaner and faster.
> Note: I will be on travel starting March 18. I would like to get this
> patch fully applied by then.
> Regards,
> Dan

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