50i fps to 25 fps

[TheCatacomb]

Am I doing things correctly? I'm trying to convert 50i fps to 25fps for DVD.

This is my Avisynth script:

FFVideoSource("G:\test.mkv")
Spline36Resize(720,576)
SelectEven()

I end up with 25fps interlaced. But is there a better method? Or is it really this simple? Thanks in advance.

My video information:

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1h 9mn
Bit rate : 10.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 50.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.096
Stream size : 4.83 GiB (99%)
Encoded date : UTC 1970-01-01 00:00:00
Tagged date : UTC 1970-01-01 00:00:00

[pandy]

Deinterlace 1080i to 1080p50 > resize to 720(704)x576p50 > re-interlace it to 720(704)x576i25 - this is best way to preserve source.

[manono]

Am I doing things correctly?

No. You forgot to deinterlace it. All you did was ruin it by resizing.

I end up with 25fps interlaced.

You ended up with 12.5 frames per second (25 very ugly fields per second). Do you want to single-rate deinterlace it (and wind up with 25fps) or double-rate deinterlace it (followed by reinterlacing it, as pandy suggests)? If you do as recommended, something like this should work:

FFVideoSource("G:\test.mkv")
Yadif(Mode=1)
Spline36Resize(720,576)
SeparateFields()
SelectEvery(4,0,3)
Weave()

[TheCatacomb]

Thanks for the replies.

You ended up with 12.5 frames per second (25 very ugly fields per second). Do you want to single-rate deinterlace it (and wind up with 25fps) or double-rate deinterlace it (followed by reinterlacing it, as pandy suggests)? If you do as recommended, something like this should work:

[SIZE="1"]FFVideoSource("G:\test.mkv")
Yadif(Mode=1)
Spline36Resize(720,576)
SeparateFields()
SelectEvery(4,0,3)
Weave()

I had tried yadif deinterlacing before, but I was missing the SeperateFields() and Weave(). Now I understand what I did wrong. Thanks again.

[Brad]

This is all assuming that you verified the source is truly interlaced, and not just an interlaced encode of progressive content.

[TheCatacomb]

This is all assuming that you verified the source is truly interlaced, and not just an interlaced encode of progressive content.

I see interlacing in the original MKV whenever there's motion. However, this is a tv recording, so if you're asking if the original showing on television was progressive or interlaced, I don't know.