Smoothness playback after transcoding?

[DarkDudae]

I am new in DV capturing, and I have captured some videos from my new Sony DCR-HC19E, and they play pretty good and softness in Media Player Classic using DV Video Decoder (The microsoft one I suppose).

Anyways, when I try to transcode for example... into XviD, or MPEG2 using VirtualdubMod, avisynth with a directshowsource... or any other tool, I get a video with the same framerate (25), the same number of frames etc... however, the playback seems to lost smoothness (It is very noticeable). I have tried it with deinterlacing filters and keeping the source interlaced.

I even tried it in other computers with the same results.

Is this usual?

Greetings

[Lycaon]

Can you post a sample of the encoded XVID file? When you have choppy playback the first thing to address is field order. And what standard is the DV Source, PAL or NTSC?

[DarkDudae]

Originally posted by Lycaon
Can you post a sample of the encoded XVID file? When you have choppy playback the first thing to address is field order. And what standard is the DV Source, PAL or NTSC?

It is a PAL source. I have been doing some testing, and the best method to get non jerky videos is this:

a = AssumeBFF().SeparateFields().SelectEven().ConvertToYUY2().LanczosResize(720,577)
b = AssumeBFF().SeparateFields().SelectOdd().ConvertToYUY2().LanczosResize(720,577)
Interleave(a.Crop(0,0,0,-1),b.Crop(0,1,0,0))

However, it doubles framerate and number of frames. So, at 50 fps the xvid encoded video plays great, just like DV source. At 25 fps, it is jerky.

I will upload the DV source and the encoded one.

Greetings

[ShawnFumo]

The smoothness loss never really bothered me all that much, but it comes from the camera grabbing two images at half a frame's length each to interlace with. This means that the DV's interlaced smoothness is actually twice the framerate. You can read a lot more about it here (especially the comparison matrix halfway down):
http://www.100fps.com/

That site recommends the Virtualdub filter "Deinterlace - Smooth", but I found that the easiest thing to use was DGBob in Avisynth:
http://neuron2.net/dgbob/dgbob.html

That does a combination of Bobbing and Weaving so that it splits the fields into two frames and either interpolates (fast motion portions) or grabs fields from the last frame (relatively still portions) for a combination of smoothness and sharpness. However, it does double the framerate. (BTW, the script you wrote out is a normal Bob, which is the same as the Bob() function. Produces a similar result as above except that it doesn't have as much resolution in non-moving portions of the screen.)

It sounds like your main alternative would be to just blend the fields (Virtualdub has this in its default deinterlace filter, marked as Best... I'm sure Avisynth can do it too). That will not be as sharp (things in motion ghost a bit), but it should reproduce the full smoothness that you want.

You can also do a "smart deinterlace" which blends the areas of fast motion (smoother) and grabs from previous frames for low motion (a little sharper), but those filters can sometimes be a pain to get a good result with.

The simplest solution for smooth motion at normal framerate (if you don't care about some blur during motion) is just the simple field blending. This is a classic square peg into round hole situation, so none of the solutions are totally perfect...

Shawn

[DarkDudae]

@ShawnFumo

Thanks for the info

[ShawnFumo]

Also, from another thread I was just reading, you may want to check out TomsMoComp for normal framerate (like smart de-interlace but with motion compensation) and TDeint (like dgbob but with motion comp). I haven't tried either yet so I can't vouch for them, but they try to actually track motion so that it can grab information from a previous frame even in areas that aren't standing still.

Shawn

[DarkDudae]

After some testing, I am using TomsMoComp (0,15,1). It seems it is not possible to keep smoothnes playback with 25fps with DV sources, but at least, TomsMoComp offers a good deinterlacing with that config.

Greetings

[Ark]

If you compare DV footage seen on TV with the same seen on PC you'll notice the same jerkiness, even with the source not recompressed to Xvid.

That's a normal behavior, a PC monitor is far superior to a simple TV, and has much quicker refresh rate. Even if you set it to 50hz, watching a PAL DV footage, you'll notice some losing of fluidity because each frame remain "impressed" on the screen pixels for far less time than on a TV, creating this "jerky" motion.

My work is editing video, and the only way to view really fluidly DV footage (but in general all types of video) is to output it to a TV.

[theReal]

It seems it is not possible to keep smoothnes playback with 25fps with DV sources, but at least, TomsMoComp offers a good deinterlacing with that config.

There is just no way 25fps video is as smooth as 50fps. I tried recording 25fps progressive on a Panasonic DVX 100AE and the results also look kind of jerky, like old film. Some people like just that, others don't...

If you don't have your 50fps interlaced source to compare with, you won't notice as much - but the non-smooth movement is still there because 25fps is just not enough (that's also the reason why nobody likes to play computer games at 25fps!)