[Kdenlive-devel] Rendering to raw YUV (with fix)

[Dan Dennedy]

On Sun, Jan 20, 2013 at 7:54 PM, Steven Boswell II <ulatekh at yahoo.com> wrote:
> Hello!  I followed the instructions at
> http://kdenlive.org/contribution-manual/how-submit-patch -- I submitted a
> bug report, which can be found at
> http://www.kdenlive.org/mantis/view.php?id=2953 , and now I'm mailing the
> kdenlive-devel list.
>
> My patch allows rendering to raw YUV.  I wanted this feature because I want
> to clean up my video clip (e.g. brightness, contrast) in kdenlive, then
> export it to raw YUV for processing in mjpegtools (where I'm one of the
> developers), then bring it back into kdenlive for editing/FX/etc.
>
> The problem is that the exported raw-video is marked as progressive, even
> though the parameters passed to MLT say that the video is not progressive!
> (My input video is miniDV, which is bottom-field-first interlaced.)  I know
> how to fix this in mjpegtools, but I'm looking to fix the original problem.
> This may be an MLT bug, in which case I'll keep digging there.  But in
> kdenlive, the "top" property in ProducerAvFormat (see
> http://www.mltframework.org/bin/view/MLT/ProducerAvformat for more info)
> doesn't appear to ever be set!

A producer is for the input. The avformat consumer is for output. The
avformat producer's top property does not need to be set with a DV
input unless you are trying to override the detected field order.

The avrformat consumer sets ILME and ILDCT on the AVCodecContext flags
when the mlt profile/consumer is set for non-progressive output. It is
not clear to me if that information is passed to the libavformat
yuv4mpegpipe. There might

>
> Does kdenlive handle interlaced video properly?

yes

> Does it keep track of the difference between top-field-first and bottom-field-first, i.e. if the
> interlacing type of imported clips differ from each other?  I haven't beaten

yes

> the other export types to death yet, but raw YUV is pretty hard to mess up,
> and it's not working right, so I thought I'd ask.
>
> Thanks for your help with this!  I'm happy to contribute to your project, if
> I can get some direction from you.