Hi,

how is it possible to render a 1080p50 project to a 1080i25 format to keep the full motion resolution of 50 fields and to be bluRay compliant?

I'm asking because my current workflow is to use 1080i25 projects and my AVCHD sources are currently 1080i25 too. Exporting such a project to 1080i25 bluRay compliant files is no problem and I'm using only "field aware stuff".
But now I like to switch to 1080p50 sources and 1080p50 projects because storage capacity and computing power to handle this at all is now available. But it should be still possible to render to 1080i25 for bluRay when needed. 50 fields and every field originates from a different p50 frame. And yes, I am loosing resolution. And with my question I don't mean the fake interlaced mode to allow p25 on bluRay.

Using ffmpeg there is a interlace filter available which can send 50 fields instead frames from a p50 source. I can specify the field order too. But it would be great to do this directly with kdenlive.

Thanks
Christian

cstark wrote:Hi,

how is it possible to render a 1080p50 project to a 1080i25 format to keep the full motion resolution of 50 fields and to be bluRay compliant?

I'm asking because my current workflow is to use 1080i25 projects and my AVCHD sources are currently 1080i25 too. Exporting such a project to 1080i25 bluRay compliant files is no problem and I'm using only "field aware stuff".
But now I like to switch to 1080p50 sources and 1080p50 projects because storage capacity and computing power to handle this at all is now available. But it should be still possible to render to 1080i25 for bluRay when needed. 50 fields and every field originates from a different p50 frame. And yes, I am loosing resolution. And with my question I don't mean the fake interlaced mode to allow p25 on bluRay.

Using ffmpeg there is a interlace filter available which can send 50 fields instead frames from a p50 source. I can specify the field order too. But it would be great to do this directly with kdenlive.

Thanks
Christian

If it's available in ffmpeg, then you should be able to create a render profile to do the same thing as the kdenlive render dialog accepts ffmpeg arguments, albeit in a different format.

e.g.
ffmpeg: -acodec flac
kdenlive: acodec=flac

cstark wrote:Using ffmpeg there is a interlace filter available which can send 50 fields instead frames from a p50 source. I can specify the field order too. But it would be great to do this directly with kdenlive.

Actually, as I now learn, there are two filters/ways to convert 50/60p to 50i/60i in FFMPEG:

The first:

Code: Select all

ffmpeg -i source -flags +ildct+ilme -vf interlace=lowpass=0:scan=tff -vcodec etc.....

or with low-pass filter:

Code: Select all

ffmpeg -i source -flags +ildct+ilme -vf interlace=lowpass=1:scan=tff -vcodec etc.....

In that case there are two components involved - the "-flags +ildct+ilme" part which specifies using interlaced DCT and Motion Estimation and the ffmpeg 'interlace' filter which interleaves the extracted fields - set to Top Field First (TFF) scan in that example.

And the second way, using another ffmpeg filter 'Tinterlace', which I was not aware of until your post prompted me to do a little searching:

Code: Select all

ffmpeg -i source -vf "tinterlace=5" -vcodec etc.....

Where "tinterlace=5" specifies TFF.
Or with low-pass filter:

Code: Select all

ffmpeg -i source -vf "tinterlace=5:flags=vlpf" -vcodec etc.....

There are no lack of web references to the MLT equivalent of the ildct and ilme flags in the context of encoding interlaced sources, some going way back, but I couldn't find anything relevant from a couple web searches along the lines of "MLT interlace filter" or "MLT Tinterlace".

That said, as CorrosiveTruths suggested, there must surely be an MLT format equivalent. The very fact that one can input 50/60p sources into a 50/60i project and render out 50/60i is proof in itself. That could be an option but you indicate that you want to edit as a 1080/50p project with the option to render out as 1080/50i ?

Only thing I can suggest is to contact one of the development team (maybe JBM) as they would surely know and be able to advise you.