Framerate conversion with GoldWave - possible??

[DRP]

My DVD player has issues with some converted DivX/XviD NTSC files which I haven't been able to yet find a solution for - I think it's a hardware issue of the player.

My latest attempts to solve this problem centre around converting the framerate from 23.976 -> 25fps. With the help of the guides to the left I have successfully managed to do this for the video but now I've got the associated audio sync problem. I understand that I need to do a similar conversion for the audio as well.

I currently use GoldWave to extract and resample audio. Rather than install BeSweet or Cool Edit Pro in addition to GoldWave just to do this one task, is there a way of doing the framerate conversion with GoldWave? I've searched but can't find it in the GoldWave help or on a guide in this site.

Please help.

Thanks,

DRP

[mats.hogberg]

If you want to do a 23.976 to 25 fps conversion of the audio, it has to be reduced in length. This is accomplished with the TimeWarp function.
Let's say the audio is 1 hour (3600 sec). 23.976/25=0.95904 3600*0.95904=3452.54 s. This is the length of the audio you want. There's also a dedicated tool for this: WavWorks (Make a forum search for it!) that's leaner, meaner and faster than GoldWave. I use it all the time when doing frame rate conversions.
But AFAIK, almost all PAL DVD players play NTSC discs without problems.

/Mats

[DRP]

If you want to do a 23.976 to 25 fps conversion of the audio, it has to be reduced in length. This is accomplished with the TimeWarp function.
Let's say the audio is 1 hour (3600 sec). 23.976/25=0.95904 3600*0.95904=3452.54 s. This is the length of the audio you want. There's also a dedicated tool for this: WavWorks (Make a forum search for it!) that's leaner, meaner and faster than GoldWave. I use it all the time when doing frame rate conversions.
But AFAIK, almost all PAL DVD players play NTSC discs without problems.

/Mats

Thanks for your answer Mats. I shall do as you suggest. I can't tell you what the problem is with playing because... well I just don't know. I've tried a million things and done so many test burns of 2 minute sections of video it's ridiculous. My TV is PAL only so in playing an NTSC disc I guess I'm getting the DVD Player to do the conversion on the fly. On some DivX/XviD conversions I do it seems to have particular trouble doing this - the video becomes staggered and jerky and the audio becomes out of sync with the video.

It's like the video almost gets converted correctly, but the audio doesn't. At this point I'm putting it down to hardware limitations of the player because I've tried literally *everything* that can possibly be changed to try and "jag" the right settings that work "just right" except framerate conversion.

I've only ever had the problem with XviD or DivX encoded AVIs at 23.976 and 23.977fps. I'm hopeful that conversion to PAL will sidestep the issue for me.

Thanks again for your suggestions.

[DRP]

If you want to do a 23.976 to 25 fps conversion of the audio, it has to be reduced in length. This is accomplished with the TimeWarp function.
Let's say the audio is 1 hour (3600 sec). 23.976/25=0.95904 3600*0.95904=3452.54 s. This is the length of the audio you want. There's also a dedicated tool for this: WavWorks (Make a forum search for it!) that's leaner, meaner and faster than GoldWave. I use it all the time when doing frame rate conversions.
But AFAIK, almost all PAL DVD players play NTSC discs without problems.

/Mats

Okay I've done this but I still end up with an audio sync problem.

I used GoldWave TimeWarp in the way you described above because I don't have a problem with the maths involved and I prefer to use software I already have where possible. My source file has been stretched slightly because VirtualDub reports it's framerate as being 23.977 rather than 23.976. I thought this might make a small difference, so I did the conversions using 23.977 in the formulae to get it just right.

I frameserved the video through VirtualDub with a change framerate instruction to 25.000fps.

I shortened the audio with GoldWave as described above by the 23.977/25 factor and saved the result.

I then used those two sources as inputs into TMPGEnc and told it it was getting PAL and to output PAL. I burnt it as PAL.

The end result plays with a significant audio sync problem both in WMP & my DVD player.

What have a done wrong? I was sure this was going to work

[bgrieb]

This is all based upon the assumption that you still have the original audio from the capture before any editing was done.

Try this, it works better than the time warp feature for me.

Make sure that your audio is 44100 KHz. If it's not, open it in goldwave and save it as such.

Use the formula that was given by mats.hogberg
23.976/25 = .95904 (or as you stated 23.977/25 = .95908)

You do not need to figure out how long the audio is supposed to be, because the percentage of change will be the same no matter how long the clip is. There will still be a small amount of drift, but it shouldn't be noticable.

Change the "playback rate" of your Audio file in Goldwave to 42295 (assuming 23.977/25, the formula is .95908 x 44100 = roughly 42295). Once you've changed that, "resample" the Audio back to 44100 KHz.

Load it in to the MPEG program of your choice and you should be good to go.

BG

[DRP]

This is all based upon the assumption that you still have the original audio from the capture before any editing was done.

Try this, it works better than the time warp feature for me.

Make sure that your audio is 44100 KHz. If it's not, open it in goldwave and save it as such.

Use the formula that was given by mats.hogberg
23.976/25 = .95904 (or as you stated 23.977/25 = .95908)

You do not need to figure out how long the audio is supposed to be, because the percentage of change will be the same no matter how long the clip is. There will still be a small amount of drift, but it shouldn't be noticable.

Change the "playback rate" of your Audio file in Goldwave to 42295 (assuming 23.977/25, the formula is .95908 x 44100 = roughly 42295). Once you've changed that, "resample" the Audio back to 44100 KHz.

Load it in to the MPEG program of your choice and you should be good to go.

BG

I've done this, but I've ended up with a WAV file *longer* than the original at 1:37:08 instead of the original 1:33:10.

Is it possible you got the formula around the wrong way? Shouldn't I be speeding it up to convert from 23.977 -> 25fps?

[mats.hogberg]

The end result plays with a significant audio sync problem both in WMP & my DVD player.

In what way is it out of sync? Gradually increasing (like it would behave if it's a frame rate problem) or out of sync from start to finish, or fine to start with, then suddenly out of sync?

I frameserved the video through VirtualDub with a change framerate instruction to 25.000fps.

Never tried that - I use AVIFRate to change the frame rate of the AVI. No need to frame serve, if you don't want to use VDub for filtering and/or editing.
My procedure for 23.976 to 25 fps, step by step:

• Load AVI in VDub, extract audio track using direct stream copy.
  Decode audio track from mp3/ac3 to wav.
  Make wav shorter (0.95904 of original) using Goldwave (or WavWorks)
  Use AVIFrate to change the fps of the AVI to 25
  Use altered AVI + shortened wav as sources in TMPGEnc set to some PAL template.

This works fine on my system.

/Mats

[DRP]

The end result plays with a significant audio sync problem both in WMP & my DVD player.

In what way is it out of sync? Gradually increasing (like it would behave if it's a frame rate problem) or out of sync from start to finish, or fine to start with, then suddenly out of sync?

I frameserved the video through VirtualDub with a change framerate instruction to 25.000fps.

Never tried that - I use AVIFRate to change the frame rate of the AVI. No need to frame serve, if you don't want to use VDub for filtering and/or editing.
My procedure for 23.976 to 25 fps, step by step:

• Load AVI in VDub, extract audio track using direct stream copy.
  Decode audio track from mp3/ac3 to wav.
  Make wav shorter (0.95904 of original) using Goldwave (or WavWorks)
  Use AVIFrate to change the fps of the AVI to 25
  Use altered AVI + shortened wav as sources in TMPGEnc set to some PAL template.

This works fine on my system.

/Mats

Please help me. I'm really begging now. I'm on my hands and knees here tearing my hair out - this is driving me nuts!

Here's what I've got and what I'm doing.

1) You can safely assume I have the very latest versions of all software that I refer to.
2) The source file is a downloaded DivX which AVIcodec & VirtualDub report as having a framerate of 23.977fps. It has an mp3 CBR audio track @ 44.1kHz.
3) I *must* frameserve the file into TMPGEnc because it won't accept it as input any other way.
4) I have a PAL only TV and despite my DVD player supposedly being able to handle all sorts of NTSC input, I seriously doubt this is true because I have never been able to get it to play an NTSC 23.976 disc without jerky motion and audio sync problems. PAL works like a charm everytime - NTSC = nightmare.
5) I have tried all the published guides on this website that use the software I have without success so far.

The software I have and use is:

TMPGEnc Plus
GoldWave
VirtualDub
AVIFrate
AVIcodec
VCDEasy
PowerDVD

and I like to think I know how to use them as well.

I am testing all sorts of different methods and programs to do the conversion and each time I do, I only do the first 2 minutes using the source range function in TMPGEnc. I have probably done this around 30 times thus far.

The audio is happening before the corresponding video. ie. you *hear* what the people say then you *see* them say it. The sync problem is present right from the start - easily evident in the first 2 minutes of a 90min long movie. Once out of sync it does not appear to get any worse - ie. it is shifted and remains shifted by the same amount all the time - this is my impression from viewing only the first 2 minutes - I might be wrong, but I don't think so.

I am extracting the audio from the source AVI with GoldWave and saving as a 44.1khz WAV file. This is the audio source in TMPGEnc. The video source is the frameserved .vdr file from VirtualDub (the only way I can get TMPGEnc to accept it).

Please help. I've run out of ideas and patience.

[DRP]

Mats,

I may have noticed something. After extracting the audio in VirtualDub and inserting it into GoldWave to do the time warp I notice the length of the audio is being reported as 1:33:09.760

VirtualDub reports the video as being of length 1:33:10.35.

There's a difference there of 0.59sec. I can't tell for sure of course but I would guess that that is the approximate audio sync duration I'm seeing.

Could it be that the audio is not supposed to start until the video has already run for 0.59sec? That would seem to explain the audio being a little bit too early right from the very start.

Is it a normal thing for the audio and video tracks to be different lengths? This seems very strange to me.

How can I go about fixing this?

[mats.hogberg]

The audio is happening before the corresponding video. ie. you *hear* what the people say then you *see* them say it. The sync problem is present right from the start - easily evident in the first 2 minutes of a 90min long movie. Once out of sync it does not appear to get any worse - ie. it is shifted and remains shifted by the same amount all the time

OK! Now this is an easy one to fix. It seems like when interleaving the audio and video stream in an AVI, the audio stream doesn't have to start at the same time as the video stream. In your case, the audio stream starts a bit later than the video stream. When you extract the audio, you lose this "delay" of the audio, so you have to compensate for it when frame serving your edited audio together with the video.
Brute force method is to actually insert some silence in the start of the wav (after shortening it as a step in the frame rate conversion) before saving it out, or you could choose wav audio in VDub, Full processing, "No change" everywhere in Conversion, and set a ??? mS delay in Interleaving. This last method, I haven't tried, but it ought to work. The first surely does.



/Mats

[DRP]

The audio is happening before the corresponding video. ie. you *hear* what the people say then you *see* them say it. The sync problem is present right from the start - easily evident in the first 2 minutes of a 90min long movie. Once out of sync it does not appear to get any worse - ie. it is shifted and remains shifted by the same amount all the time

OK! Now this is an easy one to fix. It seems like when interleaving the audio and video stream in an AVI, the audio stream doesn't have to start at the same time as the video stream. In your case, the audio stream starts a bit later than the video stream. When you extract the audio, you lose this "delay" of the audio, so you have to compensate for it when frame serving your edited audio together with the video.
Brute force method is to actually insert some silence in the start of the wav (after shortening it as a step in the frame rate conversion) before saving it out, or you could choose wav audio in VDub, Full processing, "No change" everywhere in Conversion, and set a ??? mS delay in Interleaving. This last method, I haven't tried, but it ought to work. The first surely does.

/Mats

Okay! Finally it feels like I might be getting somewhere. You're being a great help and I'm very appreciative of you hanging in here with me on this.

I'm trying this in VirtualDub first because I don't know how to add silence in GoldWave. The VDub log keeps reporting "Dub: Processing has not cycled for 10 seconds -- possible livelock." over and over again. If I switch off the audio skew correction it proceeds as per normal.

I guess this means I can't do it with VDub which is a trifle annoying. Can you give me advice on how to do the same thing in GoldWave?

I have friends & associates in Dahls-Ed, Gothenburg, Helsingborg, Bottnaryd, Överkalix & Vara. If you live anywhere near any of those, I might have someone drop a case of Vodka in to you

[DRP]

Mats,

I may have noticed something. After extracting the audio in VirtualDub and inserting it into GoldWave to do the time warp I notice the length of the audio is being reported as 1:33:09.760

VirtualDub reports the video as being of length 1:33:10.35.

There's a difference there of 0.59sec. I can't tell for sure of course but I would guess that that is the approximate audio sync duration I'm seeing.

Could it be that the audio is not supposed to start until the video has already run for 0.59sec? That would seem to explain the audio being a little bit too early right from the very start.

Is it a normal thing for the audio and video tracks to be different lengths? This seems very strange to me.

How can I go about fixing this?

Here's something weird. I've just extracted the audio again with GoldWave this time to see the length it gets.

VirtualDub reports 1:33:09.76
GoldWave reports 1:33:09.995

I wonder which is right? I guess I'll have to do two 2 minute test encodes and see which gets closer to synced when I figure out how to add the appropriate silence at the beginning of the WAV.

DRP

[mats.hogberg]

I have friends & associates in Dahls-Ed, Gothenburg,

Cool! I live in Gothenburg - but really - I don't need any Vodka (not that I don't like it... )
In Goldwave (version 4.26), just open the Edit menu and select Insert silence.
The function pops up a dialog where you can specify how much silence you want added. The silence will be inserted at the leftmost marker (which is at the start if the wav when you open a wav - right where it should be).
Hang in there - we'll soon have this fixed!

/Mats

[bgrieb]

I hope I'm not bursting your bubble, but I have never seen Goldwave's runtime match with Virtualdub's runtime. It's not a delay issue, it's just a weird glitch that I've noticed. If you try to match the audio time in Goldwave with what it says in Virtualdub, you'll find that the audio is still out of sync.

As for the Playback rate thing, I might have gotten it backwards (I'm at work and I'm going off the top of my head). Of course you are speeding up the video by making it go from 23.977 to 25 so the audio file as reported in Goldwave should loosely correspond to that which is reported in Virtualdub.

If I made the track longer the first time, sorry. Go with the opposite:

25/23.977 = nearly 1.042666....
Multiply that by the 44100 KHz and you'll get 45982.
Change the playback rate to 45982
Resample it back to 44100.


BG

[DRP]

I hope I'm not bursting your bubble, but I have never seen Goldwave's runtime match with Virtualdub's runtime. It's not a delay issue, it's just a weird glitch that I've noticed. If you try to match the audio time in Goldwave with what it says in Virtualdub, you'll find that the audio is still out of sync.

BG

Oh dear. That's not good.

I assumed VD would be closer to the mark than GW so I extracted the audio with VD then shoved it into GW, added the silence I think I need based on the times reported by VD for the video & GW for the audio of the WAV extracted by VD and performed the time warp.

Then I changed the frame rate of the AVI with AVIFrate and now I'm using that for the video input in TMPGEnc and the time warped with silence added WAV as the audio input and doing a 2min test encode.

It hasn't finished yet, so I don't know if it works or not. I'll let you know.

DRP

[DRP]

I have friends & associates in Dahls-Ed, Gothenburg,

Cool! I live in Gothenburg - but really - I don't need any Vodka (not that I don't like it... )
In Goldwave (version 4.26), just open the Edit menu and select Insert silence.
The function pops up a dialog where you can specify how much silence you want added. The silence will be inserted at the leftmost marker (which is at the start if the wav when you open a wav - right where it should be).
Hang in there - we'll soon have this fixed!

/Mats

OH MY GOD It works!!!!!

I can't believe it! Mats Hogberg I love you!

You're a very lucky man. If it wasn't socially unacceptable for men to kiss other men, you'd be in some serious trouble right now lemme tell ya!

In case anybody's interested the 2 min test I've done using the audio time produced by VirtualDub results in the audio being just ever so slightly late (*after* the corresponding image) which means I've added just a tiny bit too much silence at the beginning. For this reason I tend to think that the audio duration reported by GoldWave (which was about 2/10ths of second longer IIRC) is the more accurate of the two.

I'm going to do another 2min test this time with the audio adjusted according to the GoldWave reported times instead of VDub's. I think this will be the last test I do

Thanks for everyone's help. It is greatly appreciated.

DRP