Mental capacity

[SUBMAN1]

My work load killing me (2 more weeks left of it though). My mental capacity for the last 1.5 months is less than 40%. I cannot think straight (as a few of you may have realized lately), nor do I have much energy. I need a mental break to come back online.

I'm currently working on something of a mental break you might say though - and yes my idea of a mental break is probably a lot different than yours - Dealing with reducing an NTSC source to 15 FPS. Now you may realize that NTSC is 29.97 FPS. Most movies are actually 23.976024 FPS, and the 29.97 FPS is achieved through a drop frame. However, interlaced material is running at double NTSC at 59.94 FPS but with alternating lines and your brain puts it together at 29.97 which is basically out of your comprehension anyway so it looks like a smooth picture because your brain can't think beyond this many FPS.

Now the trick is reducing normal interlaced material or progressive material down to 15 FPS smoothly since as you may guess, 15 does not divide into 29.97, so you will get a jerk in a movie - probably twice per second. I figured out that it is bad to go through a telecide and decimate since that makes the FPS worse due to less available frames to choose from when one does not line up properly. I should just probably skip the decimate cycle or use a blending frame instead and treat the video as a pure interlaced source in an effort for smoother playback.

My expertise comes from keeping video pure so that one does not know it was compressed in the first place. I now have this iRiver Clix that deals in MPEG 4 @ 15 FPS so if anyone has any knowledge on tricking smooth playback at a slower FPS than normal, I'd like to hear it. I can do a pretty good smooth playback on it already, but just looking for some tricks from someone thats been there.

-S

PS. My AVISynth script for the current vid I am working on looks like this:

LoadPlugin("D:\Temp\dgmpgdec148\DGDecode.dll")
LoadPlugin("D:\Temp\dgmpgdec148\Decomb.dll")
mpeg2source("VTS.d2v")
ConvertToYUY2()
Telecide(guide=1,post=2)
Decimate(cycle=5,mode=1)
Lanczos4Resize(320,240)
ChangeFPS(15)
AudioDub(WAVSource("vts.wav"))

The Decimate is currently set for frame blending, but I am not sure I want that anymore.

[kiwi_2005]

Originally Posted by SUBMAN1

My work load killing me (2 more weeks left of it though). My mental capacity for the last 1.5 months is less than 40%. I cannot think straight (as a few of you may have realized lately), nor do I have much energy. I need a mental break to come back online.

I'm currently working on something of a mental break you might say though - and yes my idea of a mental break is probably a lot different than yours - Dealing with reducing an NTSC source to 15 FPS. Now you may realize that NTSC is 29.97 FPS. Most movies are actually 23.976024 FPS, and the 29.97 FPS is achieved through a drop frame. However, interlaced material is running at double NTSC at 59.94 FPS but with alternating lines and your brain puts it together at 29.97 which is basically out of your comprehension anyway so it looks like a smooth picture because your brain can't think beyond this many FPS.

Now the trick is reducing normal interlaced material or progressive material down to 15 FPS smoothly since as you may guess, 15 does not divide into 29.97, so you will get a jerk in a movie - probably twice per second. I figured out that it is bad to go through a telecide and decimate since that makes the FPS worse due to less available frames to choose from when one does not line up properly. I should just probably skip the decimate cycle or use a blending frame instead and treat the video as a pure interlaced source in an effort for smoother playback.

My expertise comes from keeping video pure so that one does not know it was compressed in the first place. I now have this iRiver Clix that deals in MPEG 4 @ 15 FPS so if anyone has any knowledge on tricking smooth playback at a slower FPS than normal, I'd like to hear it. I can do a pretty good smooth playback on it already, but just looking for some tricks from someone thats been there.

-S

PS. My AVISynth script for the current vid I am working on looks like this:

LoadPlugin("D:\Temp\dgmpgdec148\DGDecode.dll")
LoadPlugin("D:\Temp\dgmpgdec148\Decomb.dll")
mpeg2source("VTS.d2v")
ConvertToYUY2()
Telecide(guide=1,post=2)
Decimate(cycle=5,mode=1)
Lanczos4Resize(320,240)
ChangeFPS(15)
AudioDub(WAVSource("vts.wav"))

The Decimate is currently set for frame blending, but I am not sure I want that anymore.

I have low energy just reading that What do you do for a living sounds like your some movie editor:hmm:

[SUBMAN1]

Originally Posted by kiwi_2005

I have low energy just reading that What do you do for a living sounds like your some movie editor:hmm:

When I figure out my job, I'll let you know, but I think I am some sort of sys admin person on a daily basis. Depending on who walks in the door, I even have multiple business cards to make sure I am presenting the right side at any given point in time. You might say I have multiple titles, but as you may guess, this is somewhat tiring - hence my efforts to move myself out of the position I am in and on to something that I can make a difference at. I think I have worked myself into a position that I will never be promoted from because I am too valuable where I'm at. It did make me get passed over for 2 layoff's, but now I am starting to see the downside of that.

In the meantime, video - is just a hobby of mine to make perfect movies and to understand how things fit together. I am fluent in Sonic Scenarist, and as you may guess, I use AVISynth as a frameserver to filter my video productions. And as I may have guessed there is no one on this board that knows much about AVISynth scripts and filters - or at least not yet.

Anyway, if you want to do your own videos, I suggest you learn a good frame server like AVISynth. You can manipulate anything you want with it. Its only drawback is that no one takes the time to figure it out, but to anyone that does, they have a superior tool on their hands for video production.

-S

http://www.avisynth.org/

[Gizzmoe]

I loaded a 23.976 FPS source into VirtualDub and converted it to 15. The playback was ok. All I did was to set Video -> Framerate -> Convert to fps to 15.

[SUBMAN1]

Originally Posted by Gizzmoe

I loaded a 23.976 FPS source into VirtualDub and converted it to 15. The playback was ok. All I did was to set Video -> Framerate -> Convert to fps to 15.

VirtualDub is my ultimate tool for this. Its actually the only way to mux the audio back in. I created a script and DIVX won't take it as an audio source yet. Need to figure out why. Anyway, it looks OK. What I am lloking for is perfect smooth. I need some 15 FPS AVISynth info since I want to use an VirtualDUB direct stream copy if at all possible.

Cool that you know something about it Gizzmoe! If I can find a file host (Does anyone know of any?), I can post a sample.

-S

[Gizzmoe]

Originally Posted by SUBMAN1

I need some 15 FPS AVISynth info since I want to use an VirtualDUB direct stream copy if at all possible.

Try ConvertFPS instead of ChangeFPS. But it´s probably easier to just load the source material into VirtualDub...

If I can find a file host (Does anyone know of any?), I can post a sample.

www.rapidshare.de or www.filefront.com.

[SUBMAN1]

Originally Posted by Gizzmoe

Try ConvertFPS instead of ChangeFPS. But it´s probably easier to just load the source material into VirtualDub...

www.rapidshare.de or www.filefront.com.

Thanks - tried that already. ConvertFPS has a limitation of 19 FPS.

I'll try VirtualDub but since I have to frameserve the material, I find the quality better to do it (FPS conversion) before it hits Virtual Dub instead of after.

-S

[SUBMAN1]

I should point out that it already looks pretty good. It is just myself trying to get as much smoothness out of 15 FPS as possible, and maybe I can't do much better than I already have.

-S

[Gizzmoe]

Originally Posted by SUBMAN1

I have to frameserve the material

Why? Is it a format VirtualDub can´t read?

[Gizzmoe]

VOB is MPEG-2, you can read them with VirtualDub-MPEG2:
http://fcchandler.home.comcast.net/stable/

I rip the DVD first with Smartripper so that I get a single VOB, then open it directly in VirtualDub.

[SUBMAN1]

Yes, but will this convert to YUY2? DVD's native format is YV12 and that is not able to be displayed on a computer screen correctly. If there is a transfer that is going to happen, I would probably rather have AVISynth do the conversion. This way I can control how it is decoded.

Regardless though, I can remove all my filters except the YUY2 and just frameserve with AVISynth. Of course, the best quality filters will be with AVISynth, but I'll check out how VIrtualDUB does with it first.

-S

[SUBMAN1]

This right here is basically RAW video:

LoadPlugin("D:\Temp\dgmpgdec148\DGDecode.dll")
mpeg2source("VTS.d2v")
ConvertToYUY2()

[Gizzmoe]

Originally Posted by SUBMAN1

Yes, but will this convert to YUY2? DVD's native format is YV12 and that is not able to be displayed on a computer screen correctly.

AFAIK DVD format isn´t YV12. XviD and DivX use YV12 and there are no display problems as you know. Besides, VD can convert to any color format you want, as long as the target codec supports it.

Of course, the best quality filters will be with AVISynth, but I'll check out how VIrtualDUB does with it first.

I doubt that AVISynth´s filters are superior to VD´s. VD has for example excellent deinterlace and resize filters.

[SUBMAN1]

VirtualDUB does have excellent filters, but not as good as a dedicated filter. Its all in the detection rates for deinterlacing and AVISynth is way superior in that if you use Neurons Decomb filter. This is what professional people use.

Also, yes, DVD is YV12. It goes through a conversion to YUY2 before it hits your computer screen or even your TV. I'll take a screenshot of what it looks like native - its all purple shades and ugly. VirtualDUB cannot decode it without loading a YV12 filter either.

Here is the breakdown:

DVDs - These use MPEG2 with 4:2:0 YUV (YV12) color. There is one chroma sample for each square of 2x2 pixels (unlike the YUY2 picture above which has one chroma for each group of 2x1 pixels).

DV - This uses 4:1:1 YUV which has the same number of chroma samples as MPEG2 but in a different order.

Mjpeg - This can use all kinds of YUV sampling but 4:2:0 (YV12) is very common.

MPEG1, 2 and 4 (divx etc) all use YV12 color (although they can technically support other YUV modes in theory, just not in practice). There are MPEG2 profiles (such as the Studio Profile) which can deal with 4:2:2 chorma but mostly you will see 4;2:0 chroma being used.

HuffYUV - currently YUY2 and RGB storage is possible. YV12 is developmental.

HuffYUV is my favorite lossless compressor. You can squeeze about 140 GB into about 40-80 GB.

-S

[SUBMAN1]

Cool - I found a modified VirtualDUB that can read YV12. I'll take a screenshot of a non colorspace converted DVD pic - its real ugly.

-S

http://sourceforge.net/projects/virtualdubmod