29.970 - 23.976 Audio

[knight_inferno]

Heyas ^^
I live in Australia, so i normally work with PAL sources and dont have to stuff around with IVTC etc...

anyway my problem...i got a video file off a mate (its anime), the person that encoded it didnt run anything over the file when encoding, i mean like, it still has the black bars and the frame rate is 29.970, and has huge interlace lines whenever any kind of action happens. Anyhow, ive fixed it all up following helpful guides and it looks sweet now. I used GreedyHMA, my video frame rate is now 23.976 just how i want it to be, but my audio remains from the original avi 29.970, i know audio doesnt have a frame rate, but it has some kind of time delay, since im new to NTSC material, i dont know how to fix this so the audio will stay in sync with the video ^^

I hope that makes sense, any help will be great :)
Send me a link, write me a message, anything ;)

Thanks!

KNiGHT iNFeRNo

[DJ Bobo]

How did you fixed that?! it's impossible if you have received it as DivX!
Anyway, using IVTC to get 23,976fps won't change the length of the video and/or the audio.
So you've done something wrong, if it got asynch later.

And I repeat, if you received it as DivX, there is no way you can fix it! you gonna keep it as is.
If you received it as Interlaced MPEG2, your friend has done all things right, but you have made a mistake somewhere.

[knight_inferno]

no no, not impossible, just made a .avs file with all the features i wanted, cropped, greedyhma, smart smoother and warp sharp incorporated into the avs..

No more black bars, no more interlace lines during action, and it looks brilliant ^^

oh yeah, yeah it was a DivX file to! :)

I think i found a way to fix the problem, by extracting the mp3 from the original divx, making it into a wav, then using

video = avisource ("blah blah.avi")
audio = wavsource ("blah blah,wav")
autodub (video, audio)

after using that and opening in virtual dub under Frame Rate they now match and play back fine, so i dunno..guess i solved the problem...i hope ^^
while before the video was 23.976 and the audio displayed as 29.970 and they being waaay off @_@

[DJ Bobo]

NO WAY!
You gotta send me a part of that divx of yours, this is impossible, all DivX files have progressive frames. I've never seen a DivX video that is interlaced, you've gotta be kidding me! it is impossible to make IVTC on a DivX video, not in hell!

[RadicalEd]

bobotns, what are you talking about?? The guy ripped his video or capped it or whatever and didnt bother to IVTC before encoding, thats all. A video being interlaced and a codec supporting interlacing are two completely different things. Of course something can be interlaced and DivX at the same time. ::thinks:: how can I explain this to you without taking up too much time... when people say that MPEG 2 supports interlaced encoding it means that the video can be encoded by fields, so that each field is encoded as 720 x 240 at 60 fps and re-weaved for playback as an interlaced 720 x 480 30 fps image. DivX can't do this, but naturally you can still encode interlaced material. It will look like crap, since the interlace lines will be hard to encode, but of course its possible. ::sigh:: don't worry knight_inferno you will get intelligent responses from this forum *usually*

[DJ Bobo]

@ RadicalEd
I know what you mean. But he claims that he got rid of those interlaced artifacts and has decimate to smooth 23,976fps, starting from a 29,97fps DivX, which is impossible, because:
1) the interlace artifacts are part of the picture now and can't be deleted anymore, since there is no fields to deinterlace.
2) No way to get smooth 23,976fps, all what he will get is jerky playback, since he deletes frames that are not necessarely telecine frames.

and what do you mean by that:
::sigh:: don't worry knight_inferno you will get intelligent responses from this forum *usually*

If it is what I think, then let me tell you something: you're talking about yourself!

[RadicalEd]

Yea but the way IVTC works is by looking for interlaced frames, so since the lines are still there, it should still be able to identify and fix them. It would be a little harder, since some of the compression artifacts would get in the way, but its feasible. Take a look: here (http://www.angelfire.com/anime3/airanime/IVTC.html)
Dont forget to right click and 'save source as'
I posted a sample clip which was encoded at 29.97 interlaced, IVTC'ed and then re-encoded, as well as a clip that was IVTC'ed directly from the source. Pretty much the same result, some extra interlacing but nothing serious so it can be done.

Don't worry I just dont want knight_inferno to get discouraged, don't take it as too much of a personal insult, he did after all solve the problem on his own without an answer from the boards.
And yea, you're right, sometimes I do post some stupid solutions ^^' eveyone does, dun worry bout it. Anyway, check the clips out.

[DJ Bobo]

@ RadicalEd
He he, you missed a point! IVTC don't look for interlaced frames, it looks at the fields and reconstructs them to progressive output, then deletes the repeated frames.
Now, since DivX-video hasn't fields, the only thing that IVTC would do is randomly delete frames that it judges for repeated, which can't work since many frames are still combed.
So our friend here havn't fixed anything, he just made things worse ;)

[knight_inferno]

C'mon now, listen to reason ^^
There is no way that it is worse, it looks sooo much better, the original encoder was slack and encoded it straight from the source, no cropping no nothing, i had choppy playback on my machine (Duron 900, 512mb ram)..so simply i made a .avs file, greedyhma to reduce 29.970 to 23.876, VerticalReduce by 2 cuts the vertical res in half and resize puts it back up..no more interlace lines..whew..now how easy was that? Now adding smartsmoother and Warpsharp..the movie looks brilliant, i would send parts of the film, but being on dialup..i cbf'd ^^

This isnt the first time ive fixed interlace lines in a DivX either, instead of saying it cant be done (quite obviously it can be), why not try it out? =P

..though this topic isnt part of my original post, i was writing about audio sync blah blah which i fixed..if ya want to make something of this topic write in the Video section ;)

[DJ Bobo]

@ knight_inferno
IMPOSSIBLE! got it? you're kidding yourself right? reduceby2 doesn't remove the interlace lines, it blends them only, so they become like ghosts. So this doesn't reconstruct fields and so there is no way decimate can work properly!
If it was so, I could do IVTC with DVDs that way:
FieldDeinterlace()
Decimate(cycle=5)
But this doesn't work, one uses Telecide(), not FieldDeinterlace() to IVTC. And VerticalReduceBy2 works in a similiar way like FieldDeinterlace.
There is no way your 23,976fps video is smooth! you're trying to make a fool of me!

[RadicalEd]

Ah.. yea, bobotons is right there, by doing verticalreduceby2() you surely got rid of interlacing, but not really through IVTC ^^' You effectively just did a blend deinterlace by halfing it and then resizing. Anyway, I guess that works but it would generally be recommended that your friend IVTC before encoding because otherwise you are bound to get some messy results.