Cropping interlaced video

[loster]

I've captured some video from a cable box using a dvd recorder, the problem is that the cable box output includes black bars. I want to crop and re-size the video. I'm familiar with the avisynth and I've used this script before. The script was based on what AVStoDVD uses for cropping.

LoadPlugin("C:\Program Files\AVStoDVD\Lib\LeakKernelDeint.dll")
LoadPlugin("C:\downloads\dgmpgdec158\DGDecode.dll")
MPEG2Source("special 1.d2v")
ConvertToYV12(interlaced=true)
LeakKernelBob(1,7,false,false)
Crop(84,58,-86,-62)
Spline64Resize(720,480)
SeparateFields().SelectEvery(4,1,2).Weave()

My question is if this method is the generally recommended one or if there is a better way to do this? Attached is a frame grab made using dgindex and is unaltered except for jpeg compression.

[edDV]

You captured incorrectly. SD cable outputs digitally from the set top box as 524x480i over IEEE-1394. Just rescale horizontally and interlace is preserved. You can h rescale to 704x480i for true 4:3, or to 720x480i (slightly wide stretched).

Depending on the channel selected, most cable SD broadcast channels output analog 4:3 480i. If you capture 720x480i, expect eight pixel sidebars with the real video contained in the center 704x480. It should look like this and interlace is intact.

Note the 8 pixel blanking left-right.



Now I notice you are capping a 4:3 program from Nick HD... ... OK found Nick HD. Never kwew it existed.

The show is 4:3 so HD cap shows side pillars.



If I cap the HD channel off SD S-video the 16:9 outer frame is letterboxed
(pillared inside letterbox .. hence 4 black edges.).



And the correct answer is ... Find the SD Nick and record that as 4:3.



Never knew I had 3 Nick channels.

SD analog 480i
SD digital 524x480i
HD 1920x1080i

[manono]

You should be able to IVTC it to progressive video and then crop and resize it.

[loster]

My cable company no longer has SD versions of channels when using a cable box. I have Cablevision on Long Island. I will try finding the channel in clear qam. I could capture using the analog channel but they are supposed to shut those off soon. IVTC might be problematic since the program was originally PAL.

[manono]

IVTC might be problematic since the program was originally PAL.

Then unblend it if that's what it takes. Rather than having us guess what you have, you could always upload a sample for us to have a look.

To answer your original question, although there are better bobbers these days than LeakKernelBob, your script is OK for cropping and resizing interlaced sources.

[loster]

Ok I've uploaded a sample. Hopefully it's long enough. I will probably try some other deinterlacing filters if I can't get the cable box set up correctly for capture. Looks like it won't output the 4:3 image without borders on all four sides.

[manono]

If it were I, I'd unblend it rather than reencoding it interlaced:

Yadif(Mode=1)#or your favorite bobber
SRestore()

http://avisynth.org/mediawiki/Srestore

[jagabo]

Mpeg2Source("20sample.d2v", CPU=2)
AssumeTFF()
Yadif(mode=1, order=1)
SRestore()

[loster]

Yep might try that.
I checked the cable box again but it wont output 4:3 over s-video without borders. I might try disconnecting the component output and see what happens.

[loster]

Ok that didn't work. Looks like the cable box will always add the borders when using s-video. I tried several settings and disconnecting the hdmi output (I forgot that the new cable box is connected with hdmi). Look like I'm stuck resizing or capturing with another device (one with component or hdmi inputs).
I'm tempted to just give up and leave them as-is with the border and just use the zoom feature..

[jagabo]

You might try something like this:

Mpeg2Source("20sample.d2v", CPU=2)
AssumeTFF()
QTGMC(preset="fast")
SRestore()
Crop(88,58,-88,-62)
Deen(thry=20, thruv=25)
nnedi3_rpow2(2)
Spline36Resize(720,480)

before:


after:

[loster]

Might be worth a look. At least I learned a little more about interlacing and resizing.

[loster]

I have another related question. If i decide to capture the component video what equipment do I need? I know that I will need a capture card for my computer or another way to record the component output. I looked and it seems that conversion of component to s-video is difficult. Does anyone have some advise? I'm tempted to just buy a black-magic intensity pro (and a new computer) and hope that I can use it with the cable box. I know that my current setup isn't up to the task.

[jagabo]

There aren't many component video capture devices. Black Magic Intensity Pro, Hauppauge HD PVR, AverMedia HD PVR.

[edDV]

Also, for SD analog component to DV format there is the later ADS Pyro plus others >$500.

[TBoneit]

Note that I haven't tried these. I would expect some quality hit, I could also be wrong on that.
I would look at reviews before buying.
http://www.monoprice.com/products/product.asp?c_id=101&cp_id=10114&cs_id=1011407&p_id=...seq=1&format=2 is an example of one such Component to S-Video & Composite device.
Also on Amazon for example.

[loster]

Thanks for all the information. I'm not really sure about committing to any of the options. If I do decide to buy something I guess I will post an update.