1080i to 720p

[egrimisu]

Hey guys,
i have a video footage recorded with my cam that is in 1080i format. what filter to use to convert it to 720p(deinterlace,resize if needed)

thanks.

[pandy]

yadiffmod?, Lanczos?

[henryho_hk]

What r u using the 720p result for? Low(er)-bitrate MKV? M2TS?

[Usedocne]

QTGMC + Spline36Resize maybe?

[rec]

I do this all the time. It's a two step process. 1) Deinterlace 1080 60i to 1080 60P. 2) Resize to 720 60P.

There are of course, a number of options for deinterlacing. I use Yadif which is a good practical solution for quality and speed.

Script:

aviSource("Your_movie.avi")

Load_Stdcall_plugin("C:\Program Files\AviSynth 2.5\plugins\yadif.dll")

Yadif(mode=1, order=1)

lanczos4resize(1280,720)


This assumes upper field first.
It will work fine with 50i material, too.

[egrimisu]

Thanks guys, worked fine.

[MrVideo]

Thanks guys, worked fine.

Ya, I'm curious as well. Why are you throwing away higher resolution images?

[Ghitulescu]

The visual (optical) resolution of a camcorder is not even on par with 720p .... ;) Don't mix up pixels with visual impression.

[egrimisu]

well as i know 1080i frames are made from 2 fields that means that the rezolution of 1080i is actualy 960x540. that's why :)

[Alex_ander]

1080i frames are made from 2 fields that means that the rezolution of 1080i is actualy 960x540.
It doesn't mean that. You actually never watch one field of a frame separately from the other, despite the fact they appear one by one. At least for the reason human visual perception is not as fast as fields follow.

[burfadel]

Make sure you use Yadif 1.7, not the older one that is floating around. It is a little faster and deinterlacing 1080i will benefit from it.

The 2 fields statement above is correct, you are effectively coverting 1080i 60 fields/second (for NTSC etc), 1080i 50 fields/second (For PAL) to 1080P 30 frames/25 frames a second. The CAM recorded material at 60 fields/second is not the same as movie content at 60 fields/second, as it really is effectively 30 frames/second. Movie (film) content is 23.976 frames/second, in which case you would you an inverse telecine and decimating filter instead, as there are mixed frames introduced to get it to 29.97 (30...) fps. The mixed frames can cause shuddering during movement.

In terms of resizing, spline36resize may produce better results than using lanczos4, and spline64resize, although slower, should produce even better results again.

[-Vit-]

I know this has been answered but there's a good speed-up that hasn't been noted. Resize horizontally before deinterlacing, giving the deinterlacer less data to process, then do the vertical resize afterwards. Works because deinterlacing is primarily a vertical process. Can be used regardless of deinterlacer, for example with QTGMC (http://forum.doom9.org/showthread.php?t=156028) (assuming 16:9):
Spline36Resize( 1280,1080 )
QTGMC( Preset="Very Fast" )
Spline36Resize( 1280,720 )

The high-speed QTGMC presets were designed for doing high quality HD deinterlacing in reasonable time. "Very Fast" is the fastest mode that uses NNEDI2 (likely to be NNEDI3 in the next revision). The faster modes ("Super Fast", "Ultra Fast") use a Yadif variant, but with better quality.

[Usedocne]

@-Vit-

Nice tip, I never thought of doing it that way, it's so simple when you think about it.

[ajp_anton]

well as i know 1080i frames are made from 2 fields that means that the rezolution of 1080i is actualy 960x540. that's why :)

1080i "resolution" varies between 1920x540 for scenes with lots of motion, and 1920x1080 for scenes with very little motion.

[WILLIS]

I know this has been answered but there's a good speed-up that hasn't been noted. Resize horizontally before deinterlacing, giving the deinterlacer less data to process, then do the vertical resize afterwards. Works because deinterlacing is primarily a vertical process. Can be used regardless of deinterlacer, for example with QTGMC (http://forum.doom9.org/showthread.php?t=156028) (assuming 16:9):
Spline36Resize( 1280,1080 )
QTGMC( Preset="Very Fast" )
Spline36Resize( 1280,720 )

The high-speed QTGMC presets were designed for doing high quality HD deinterlacing in reasonable time. "Very Fast" is the fastest mode that uses NNEDI2 (likely to be NNEDI3 in the next revision). The faster modes ("Super Fast", "Ultra Fast") use a Yadif variant, but with better quality.

im trying to use this exact script Vit posted, however with the super fast or ultra fast preset...I am getting an error in my script saying that there is no function named yadif. I have both yadif and yadifMod in my plugins folder, so what seems to be the problem? thanks

[Didée]

Yadif.dll cannot be auto-loaded, because it's a C-plugin. It has to be loaded manually with LoadCPlugin() or Load_Stdcall_Plugin().

YadifMod.dll can be auto-loaded, but it's a different filter with a different name. If the script says "Yadif", then "YadifMod" ain't work, obviously.

[henryho_hk]

Try putting a file "LoadCPlugin.avsi" in the plugin directory, with the contents:

LoadCPlugin("<<<full path with drive>>>\yadif.dll")

[Ghitulescu]

have a look also in this almost identical thread -> http://forum.doom9.org/showthread.php?p=1447319#post1447319