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Old 3rd December 2002, 20:08   #1  |  Link
Stress_analyst
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Problems with IVTCing hybrid? video

Hi everyone,

Please forgive my ignorance on the subject and I must say that I’m intimidated posting in this particular forum (since all the developers and very knowledgeable people post here). I have been working in DVD’s for about a year, but my knowledge in complicated streams is limited...

I’m facing a very peculiar situation and I could use your help. I’m trying to backup my recordings from a PVR (personal video recorder, records satellite signal to its hard drive and can be played back to the TV). Lately the appropriate software became available for transferring the recordings from the PVR’s HD to my PC. The resulting files are video.m2v and audio.mp2/AC3.

I think that Donald Graft is aware of this issue and I was wondering if there is a solution to processing the video streams correctly. While processing the video files in DVD2AVI I get a report of a NTCS 15% and FILM 85%, progressive/interlaced, 29.97 constant (640x480). The recording is “Harry Potter”. When I examine the video in Vdub I see the 3:2 count on the interlaced frames. So I’ve tried the following avs script (for Hybrid video) end encode with CCE:
.avs:
Telecide()
Decimate (mode=1,threshold=50,quality=3)

CCE settings:
Add sequence end code
Progressive frames
Linear quantizer scale
Zigzag scanning order

Remux with Ifoedit 095

The output is NTSC, progressive, 29.97, 640x480.

It plays fine in the PC but in my stand alone I see horizontal break lines all over the place. These lines are not visible when I fast forward the produced DVD.

ALSO these lines are not visible if I resize to 480x480, crop and add borders!!!

Is there a reason for the need of resizing? I understand that I’m not dealing with a regular DVD problem (since my source is a satellite line), but by reading the IVTC doom9 guides and many posts in this forum I thought that I could apply the same filters, which I think they are correct, and process the stream correctly.

Thank you for bearing with me…
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Old 3rd December 2002, 22:32   #2  |  Link
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What is a "horizontal break line"?
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Old 3rd December 2002, 22:56   #3  |  Link
Stress_analyst
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horizontal break lines

Hi,

I did not express myself correctly. By “horizontal break lines” I mean short horizontal thin white lines all over the screen. It is not like the horizontal ripple that you see at an interlaced frame. These are horizontal, short, pencil thick, white lines everywhere on the screen. I’m not sure if this description is clear, or if this is a common artifact.

I wish I could take a snapshot of the picture but my TV doesn’t have a TVOUT, and these artifacts are not visible in my monitor when I use my DVD-ROM. I could try to capture from my DVD player to my PC with my capture card (I might be able to capture these lines)...or…I could just take a snapshot of my TV’s screen with my digital video camera and post the picture in this thread.

Let me know if this artifact /distortion is common or if I need to post a picture.

Thank you for the response.
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Old 3rd December 2002, 23:07   #4  |  Link
DJ Bobo
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This is no hybrid stream.
Hybrid streams have some true 30fps parts and some true 24fps.
You stream is 100% 24fps, with some parts being telecined.

If you wanna use Decomb, use it this way:
Telecide()
Decimate(cycle=5)

If you wanna use IVTC2.2 (downloadble from doom9 download page), which is better IMHO:
ivtc(70,10,25)

You'll get 100% 24fps, without any parts being telecined, and encode as you done above in CCE with progressive frames & stuff.

Then you'll get a 24fps perfect progressive stream, without any interlacing lines or whatsoever.

BTW, with 24 I mean 23,976 and with 30 I mean 29,97
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Old 3rd December 2002, 23:32   #5  |  Link
Stress_analyst
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IVTC

Hi,

I thought that this was not a true hybrid video and the 3:2 count indicated that I should use a script for IVTC. So I did use a script with:

Telecide()
Decimate(cycle=5)

But the lines were still there.
Is there something in my CCE settings that creates the problem?
And why are the artifacts disappear when I FFW or resize to 480x480?

I will try again tonight with a short part of the stream, just video, but I know that I tried to IVTC and it didn’t work…

Thank you for the responses
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Old 3rd December 2002, 23:45   #6  |  Link
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Would you like me to move this to the CCE forum?
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Old 3rd December 2002, 23:50   #7  |  Link
slk001
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640x480 is not a valid DVD resolution (neither is 480x480). Your horizontal lines may be due to the resolutions you are using. Try resizing everything to 720x480. Try addind this command:

BILINEARRESIZE(720,480)

Also, for the IVTC'ing, use

TELECIDE(guide=1)

(as a minimum) for true 3:2 pulldown material.
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Old 4th December 2002, 19:02   #8  |  Link
Stress_analyst
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Hi everyone,
Thank you for the comments.

I did some testing last night with different filters and resizing (10 combinations) and the results were consistent:
As long as I didn't resize (to 720x480, or to 480x480) the final picture had the lines (maybe you are calling this flickering???).
When I resized the picture the artifacts were gone.

Adding borders or cropping (after resizing) had no effect, since the initial resizing solved the problem. Both IVTCing or processing as a hybrid video resulted in a smooth video, as long as resizing was performed first, but I think that I've got faster speeds with IVTCing.

I don't understand why resizing is mandatory in these streams.

I realize that 480x480 is not a standard DVD size but ANY resizing solved the artifacts issue (I think that my Apex just plays everything, but some stand alone players do require a DVD standard stream).

I think the best results came from using the "DVD compliant" option with CCE and no resizing command in the script (resulting to a 720x480).

If someone has an answer about the resizing or any further suggestions I will be happy to hear them.

Thank you for advising and I’m sorry for taking so much of your time.
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