Best deinterlace method?

[Wario]

Hi everybody,

I capture my video in AVI format with (MJPEG/HUFFYUV) codec in 640x480 (NTSC) 29,97fps and my video is interlaced. Ok but now i use VIRTUAL DUB to convert in DIVX & DEINTERLACE my video but i just want to know if you have better idea or better filter to deinterlace my video...
for now i use "avisynth" with "Bob.SelectEven" filter and sometime i use SMART DEINTERLACE but depends on the source of the video.. !.

Thx for you help ;-)

[Awatef]

Use decomb in avisynth

If you want it to be blended: FieldDeinterlace()
If you want it to be interpolated: FieldDeinterlace(blend=false)

[Wario]

What the difference between

blended: FieldDeinterlace()
interpolated: FieldDeinterlace(blend=false)

and do you have a EXEMPLE of your SCRIPT (.avs)

[Awatef]

see the difference for yourself

there is no particular script:

avisource("filename.avi")
LoadPlugin("...\decomb.dll")
FieldDeinterlace()

OR

avisource("filename.avi")
LoadPlugin("...\decomb.dll")
FieldDeinterlace(blend=false)

or you can make IVTC if the capture is actually a 24fps source, as described in the AviSynth forum.

[theReal]

I like Smartdeinterlace very much, my "standard" settings are:

SmartDeinterlace(2,10,true,[true|false],true)

the values are for:
SmartDeinterlace(mode,treshold[,denoise[,blend[,fast]]]).

Blending compresses better but can result in "ghosting" effects.


However, the ultra-best deinterlacing method is encoding with 50fps:

First, use the seperatefields command in avisynth, then load into VDub and use the "deinterlace - smooth" filter by Gunnar Thalin.
The filter is very slow and the resulting files are a little bigger, but the quality, especially for high motion content, is stunning.
More on this on www.100fps.com

btw. for this to work you need to capture in full resolution, 640x480 doesn't work.

[Wario]

I have tested the guide from www.100fps.com and i agree with you!.. Quality but big file size :-(...

What do you mean FULL RESOLUTION..
640x480 its a full resolution no?...

[theReal]

Full resolution PAL or NTSC.

For PAL this would be 720x576 (or 768x576 in 4:3)
Only with 576 lines (or 448 in NTSC, I think), you will get the two fields correctly

[Wario]

Are you sure :confused: because when i capture in 640x480 i think i have two fields correctly ?... but i think full resolution for NTSC is 720x480 (but its not a 4:3 ratio)... :scared:

[theReal]

You're right, NTSC is 720x480 and you get all the lines correctly with 640x480.

My first thought was about PAL - when you capture PAL with 640x480 then you don't get the two fields correctly (but you can still remove combing with Smart Deinterlace).

[Wario]

Ok thx to correct me ;-)
But do you know if its better to capture with two fields
(because i use MJPEG) and i can choose if resolution is higher than 240 capture in two fields )

[smok3]

Originally posted by theReal
However, the ultra-best deinterlacing method is encoding with 50fps:

First, use the seperatefields command in avisynth, then load into VDub and use the "deinterlace - smooth" filter by Gunnar Thalin.
The filter is very slow and the resulting files are a little bigger, but the quality, especially for high motion content, is stunning.
More on this on www.100fps.com
1. hrm, i tryed that method with vdub (1.4.10 i think), source was matrox-digisuite-mjpeg avi file (captured from analog betacam), somehow it just encoded about 1/4 of the file, any ideas what might be the deal here? (i used 2pass divx5.02)

2. how is with playback of 50 fps file on slower computers? (or is that the same/or similar as for 25 fps?)

3. what is the suggested resolution/bitrate for 25 fps 3:4 and 50 fps 3:4 divx5 movie to get good playback on variety of machines?

4. (if some1 know) what would a tv station have to pay to use divx5 for its demo cds? (actualy mux of mp3&divx5 :P) (or can i just use some version of xvid? (things must be simple for the final user of course))

tia,

smok3

[theReal]

I can't imagine why it would only encode 1/4 of the file, never happened to me.

The playback of 50fps Divx 5 is a lot harder for the cpu than 25 fps (cpu load is more than doubled, from my experience).
I encode tv captures with 384x288 for 50 fps because the file gets too big otherwise and the resolution is still higher than "normal" 384x288 - it has more temporal resolution, not spacial. In my opinion, it looks just as good as 512x384 with 25fps (deinterlaced with smart deinterlace) and it is about the same filesize, but high motion looks much better with 50 fps.

The "blend" setting in the smooth deinterlace filter makes the file much more compressible, but it blurs motion scenes a bit. This is ok for tv captures, but not ok for encoding DV. I tested a few DV scenes lately and found 640x480, 50 fps with the default smooth deinterlace settings to be very very close to DV when encoded with quant 4 or 4.5. Unfortunately, the bitrate shot up to somewhere between 6000 and 8000 :(

[smok3]

This is ok for tv captures, but not ok for encoding DV

thats interesting, i did a test with smart deinterlacer as well (filters were like: 1.smartdeinterlacer(framestuff, blend), 2.sharpen(10-15), 3. precize bicubic resize 608x4something),original was 720x576, but since the clip had titles and subtitels burned in the 'blend' option in smartdeinterlacer was mucho better than default (got some color artifacts around edges of the titles and also edges of some objects were aliased (there was lots of cromakeys in clip as well)), i guess ill have to connect the digibeta to get similar (clean) input as dv (must do some further tests anyway).

The playback of 50fps Divx 5 is a lot harder for the cpu than 25 fps (cpu load is more than doubled, from my experience).
i guess ill just forget about this method then :)



btw, some dvcams can record in sort of progresive 25 fps mode, why dont u try that?

tnx for answers,

smok3

[theReal]

I think the Sony PC-100 can't record progressive. But even if it could, I primarily want to watch the recordings on tv from the dv tape, so interlaced is better anyways.

If you encoded at an average bitrate with blended vs. interpolated deinterlacing, then probably the blended deinterlacing was better because it really compresses much better (= less artefacts). I tried it with fixed quality encoding, so the interpolated looked better.
However, I wouldn't encode a clip with the best looking settings because I don't want to end up with bitrates of ~8000...

[smok3]

I tried it with fixed quality encoding, so the interpolated looked better.
However, I wouldn't encode a clip with the best looking settings because I don't want to end up with bitrates of ~8000...of course :)

interlaced is better anywayswell, depends on the eye, i just love that 'film' look, even worse - i hate interlaced stuff :), no, lol, even worser - i like that filmlikefilter that new divx decoder has, :D.

smok3

[theReal]

hmmm, I also like the new film-filter! It's really good for most divx movies, especially when you watch them at a low monitor resolution.

On the other hand, when I render DV video with Ulead set to progressive instead of field-order A, I find the picture slightly flickers on the tv screen. I have never seen a real progressive DV recording, though.

[smok3]

sure, things that are interlaced should be rendered as 'field rendering' (dont know ulead tho).