Quick Question Interlaced DVD

[mpeg4_tech]

I'm still using the GKnot .27, with divX 5.02 method, and I have a question regarding an interlaced DVD. (I hardly ever rip these types of DVD's) I can usually just Force Film during the DVD2AVI process. However a few days ago I ran across a DVD that was interlaced, so I didn't force film during the DVD2AVI process, and I checked IVTC during encoding. The movie turned out very much out of sync with audio, so my question to "clarify" is, since I didn't force film, the d2v FPS was 29.970 after the DVD2AVI process, was I "suppose" to set the FPS (In GKnot) to 23.976 anyway (even though the d2v file was 29 cuz I didn't force film)?

I did set it to 23.976, cuz thats how I interpreted the guide, however, the Log file (after encode) had a section that stated the differences weren't matching. I just wanted to clarify if I did everything properly by setting the FPS to 23.976, even though I did not force film during the DVD2AVI process? Thanks

[CaPPyD]

If it is INTERLACED content on every frame, then you want to DEINTERLACE. If you have interlaced content on only 2 out of 5 frames, then you IVTC.

I suggest you read Force Film, IVTC, and Deinterlacing - what is DVD2AVI trying to tell you and what can you do about it? (http://www.doom9.org/ivtc-tut.htm)

Then go back and read it again. Then try to re-encode your video.

[manono]

Hi-

To elaborate a bit more. Following CaPPyD's guideline, if every frame is interlaced, you put on a deinterlacer, keep it at 29.97fps and do not check the box.

If only 2 of 5 frames are interlaced, you put on IVTC and check the "IVTC in .avs->correct Frame Count" box.

[mpeg4_tech]

[QUOTyou IVTC.E]Originally posted by CaPPyD

I suggest you read Force Film, IVTC, and Deinterlacing - what is DVD2AVI trying to tell you and what can you do about it? (http://www.doom9.org/ivtc-tut.htm)
Then go back and read it again. Then try to re-encode your video. [/QUOTE]

Thank you for the links, they are an excellent learning source. I will read and re-read, thanks.

[mpeg4_tech]

Originally posted by manono

If only 2 of 5 frames are interlaced, you put on IVTC and check the "IVTC in .avs->correct Frame Count" box.

I never noticed that box, IVTC in .avs->correct Frame Count" box?
Perhaps since I rarely deal with interlace source dvd's, I overlooked it. The rare times when I did check IVTC, I never noticed a correct Frame Count box in addition to the IVTC box.

Anyways, hopefully I'll figure it out by reading the links provided, I understand a lot more then I did, so thanks.

[manono]

Hi-

I never noticed that box, IVTC in .avs->correct Frame Count" box?

I thought that's the box to which you were referring. Changing the box in the Bitrate Tab to 23.976fps is useful for getting accurate compress test results (if you added IVTC to the .avs script-otherwise your results will be for 29.97fps and 20% lower). But when encoding the full movie, it's necessary to check the "IVTC in .avs->correct Frame Count" box (in Encoder-Add Job-Encoding Control Panel) so that GKnot knows to adjust the number of frames.

However, none of that explains why your audio got out of synch, since at 23.976fps, or at 29.97fps, the film length is the same and audio synch shouldn't be affected. You didn't by chance downsample to 44,100 Hz? Also, did you fill in the Delay in Encoder-Add Job-Encoding Control Panel-Audio 1? If the problem persists, perhaps post the log file.

[mpeg4_tech]

Originally posted by manono
Hi-

I never noticed that box, IVTC in .avs->correct Frame Count" box?

I thought that's the box to which you were referring. Changing the box in the Bitrate Tab to 23.976fps is useful for getting accurate compress test results (if you added IVTC to the .avs script-otherwise your results will be for 29.97fps and 20% lower). But when encoding the full movie, it's necessary to check the "IVTC in .avs->correct Frame Count" box (in Encoder-Add Job-Encoding Control Panel) so that GKnot knows to adjust the number of frames.


The "Box" I am/was referring to is the FPS (frames) which has 23.976,25.000,29.970,30.000, and 24.000. Perhaps you're talking about the same numbered frame box, you're just throwing me off when you are referring to it as (IVTC in .avs->correct Frame Count" box) I'm not as experienced of an encoder as you are, so please let me know if we are talking about the same box? :D

Basically what I just wanted to clarify is, if I ever need to use the IVTC (I won't force film in DVD2AVI), so the d2v will be 29.970 when I load it into GKnot. I just wasn't sure if I needed to change the 29.970, to 23.976 while I utilize the IVTC filter to encode.

[mpeg4_tech]

Originally posted by manono
Hi-
I thought that's the box to which you were referring. Changing the box in the Bitrate Tab to 23.976fps is useful for getting accurate compress test results (if you added IVTC to the .avs script-otherwise your results will be for 29.97fps and 20% lower). But when encoding the full movie, it's necessary to check the "IVTC in .avs->correct Frame Count" box (in Encoder-Add Job-Encoding Control Panel) so that GKnot knows to adjust the number of frames.


Okay I located the IVTC in .avs->correct Frame Count" box. We were not talking about the same box. I am asking about the FPS box in the beginning right when we load the d2v into GKnot. So if you could please answer the below question, thanks.

Basically what I just wanted to clarify is, if I ever need to use the IVTC (I won't force film in DVD2AVI), so the d2v will be 29.970 when I load it into GKnot. I just wasn't sure if I needed to change the 29.970, to 23.976 while I utilize the IVTC filter to encode?

[jggimi]

Leave that box at 29.97.

If you use "Force FILM" your .d2v file, when opened, will already be at 23.976. But...

When you select IVTC for Telecined content that cannot be "Force FILM"ed, the AviSynth script (.avs file) created will feed video at 23.976 to VirtualDub. The script's IVTC filters do this.

Checking that "frame count" box is required by Gknot when you are doing the optional end-credits in low quality.

But as Manono said, none of this affects audio synch. He asked, ...You didn't by chance downsample to 44,100 Hz? ... as that can cause synch problems. If your audio bitrate is below 128kbps, you may have unknowingly downsampled the audio to 44.1Khz, unless you used the "--resample" option, as TheWef describes in the Help tab of Gknot.

[mpeg4_tech]

Originally posted by jggimi

But as Manono said, none of this affects audio synch. He asked, ...You didn't by chance downsample to 44,100 Hz? ... as that can cause synch problems. If your audio bitrate is below 128kbps, you may have unknowingly downsampled the audio to 44.1Khz, unless you used the "--resample" option, as TheWef describes in the Help tab of Gknot.

The links/tutorials along with all the feedback have helped me understand what I did wrong, and gain more knowledge. I did not downsample to 44,100Hz, the audio bitrate was 128kbps and everything was set properly, with the exception that I did not check IVTC in .avs->correct Frame Count" box. In addition, I changed the 29.97, to 23.976 when I loaded the d2v file in GKnot (Right after the DVD2AVI process). I also probably should have used a deinterlace filter instead of the IVTC cuz I'm quite sure the DVD source was Interlaced all the way throughout the movie. I did not check frames as suggested though, but I'll start checking frames and following the tutorials regarding this issue. BTW, the DVD source was "Jackass the movie".
I hardly ever run into DVD sources where I need to "not" force film in DVD2AVI, and use IVTC, or deinterlace filter. So even though I've encoded approx 180 movies so far (Force Film), I'm still learning and have a lot to learn. Thanks for your feedback.