Frame rate conversion help

[Og]

Hi, I'm new here so I hope this is the correct forum.

I have a Cheap Chinese Crap™ camcorder that records in 720x480 , 60FPS MJPG format. I have recorded many hours of home video which plays fine in my PC but trying to play them in my DVD player results in "slow motion" picture and audio.
I use Vdub for conversion and the converted movie is 480x320 60FPS XviD with MP3 audio. I am assuming that the slo-mo is a result of the non-standard FPS so I wanted to convert the FPS to something lower but could not do it with Vdub.
I have googled for solutions and found old, outdated and too complicated guides, and that includes VideoHelp (namely this).

Basically what I'm looking for is a simple one-freeware-software solution to convert 60FPS to either 30FS or 29.97FPS, or maybe a not so simple way but with VirtualDub, or, failing that, a contemporary guide using free software.

Any help will be appreciated.

[T_Jet]

Simplest way in VirtualDub

Video -> Frame Rate -> Frame Rate Conversion

Select "Convert to fps" and enter your desired frame rate. I'd suggest 30 as it's half the rate of your original

[dragonkeeper]

I've not had much luck with this type of conversion solely using virtual dub. I would recommend frameserve to VDub using avisynth. using SelectEvery(2,0) or SelectEven(). Something like this.

AVISource("C:\myVideo.avi")
SelectEvery(2,0)

Play the file in mpc to see if the resuting vide is what you want

P.S the guide you linked to are for format conversion NTSC<>PAL, they really are not applicable to what you want to do.

[Og]

My bad, I should have mentioned that I have already tried all of the "Video -> Frame Rate" options with no success. The process you described results in a video that plays in slow motion and skips a second or two occasionally while the audio is normal.
Some things to note: I'm using "direct stream copy" on both audio and video (I think I also tried with "full processing mode" before), and also, I haven't tried this with my DVD player as the slo-mo is apparent when playing in my PC (VLC or MPC).

Thanks for trying, though.

[EDIT]
This was a response to T_Jet's post. Didn't see dragonkeeper's when I was replying.

[Og]

AVISource("C:\myVideo.avi")
SelectEvery(2,0)

Brilliant! That worked like a charm!

Many many thanks dragonkeeper

[manono]

I use Vdub for conversion and the converted movie is 480x320 60FPS XviD with MP3 audio.

Haven't you noticed the aspect ratio is off, that people are too 'fat'? That ratio is 1.5:1, the same as a DVD and the same as your source but, unlike an NTSC DVD, doesn't get resized at playback time. What you want (if you really want a low width such as 480 and if the DVD is 4:3) is 480x360.

This assumes you're not setting a PAR when reencoding, but then why would you with such a major resize? It also assumes this 720x480 MJPEG you're capturing is supposed to be resized to something like 640x480 during playback.

[jagabo]

My bad, I should have mentioned that I have already tried all of the "Video -> Frame Rate" options with no success.

Using the frame rate options you can get any frame rate you want and and speedup or slowdown. Set the Source Frame Rate to 60 if it's not already 60. Set the output frame rate to Decimate by 2, or manually specify 30 fps. And don't use Direct Stream Copy.

[Og]

Using the frame rate options you can get any frame rate you want and and speedup or slowdown. Set the Source Frame Rate to 60 if it's not already 60. Set the output frame rate to Decimate by 2, or manually specify 30 fps. And don't use Direct Stream Copy.

As I said, I already tried all the options in VDub but only with direct stream copy. Now I tried it with full processing mode and indeed it does work great.
It's a little weird that an option would work differently in FPM and DSC. I have expected it to either not work at all in DSC or work exactly the same as in FPM.
Anyway, for me this is better than using Avisynth so kudos jagabo !

Haven't you noticed the aspect ratio is off, that people are too 'fat'? That ratio is 1.5:1, the same as a DVD and the same as your source but, unlike an NTSC DVD, doesn't get resized at playback time. What you want (if you really want a low width such as 480 and if the DVD is 4:3) is 480x360.

This assumes you're not setting a PAR when reencoding, but then why would you with such a major resize? It also assumes this 720x480 MJPEG you're capturing is supposed to be resized to something like 640x480 during playback.

I can't say understand all of the technical stuff you said, but I didn't notice stretching at all. If by PAR you mean the aspect ratio, then I am setting it to "same as source" in VDub's resize filter.
It's probably moot anyway, as the 480x320 was just a temporary setting to rule out resolution issues when I was testing what causes the movie to be played in slo-mo. Now that I found the problem I see no reason to not keep the original resolution of 720x480 as my DVD player seems to work fine with it.

[manono]

OK, but you didn't say that the XviD wasn't intended as the final output format. If it was just a test, then fine. But people were still fat at 480x320. They won't be when encoded as a 4:3 DVD at 720x480.

But, one then wonders what you're doing in VDub at all if the final intended output is to be a DVD. It's not an MPEG-2 encoder. Much more efficient would be to use an AviSynth script doing the frame decimation as suggested earlier by dragonkeeper and opening that script directly in your MPEG-2 encoder, whichever one you plan on using. You can do the correct colorspace conversion and any other filtering you might want, in that same script.

[AlanHK]

As I said, I already tried all the options in VDub but only with direct stream copy. Now I tried it with full processing mode and indeed it does work great.
It's a little weird that an option would work differently in FPM and DSC. I have expected it to either not work at all in DSC or work exactly the same as in FPM.

Direct Source Copy -- COPIES data from the SOURCE file. It does not apply any filters or encoding.

If you want to make any changes, (except for just cutting out segments) you need to "PROCESS" it.

[Og]

Direct Source Copy -- COPIES data from the SOURCE file. It does not apply any filters or encoding.

If you want to make any changes, (except for just cutting out segments) you need to "PROCESS" it.

Exactly, that's why I was misled by the fact that it DID in fact change the output when using DSC.

OK, but you didn't say that the XviD wasn't intended as the final output format. If it was just a test, then fine. But people were still fat at 480x320. They won't be when encoded as a 4:3 DVD at 720x480.

But, one then wonders what you're doing in VDub at all if the final intended output is to be a DVD. It's not an MPEG-2 encoder. Much more efficient would be to use an AviSynth script doing the frame decimation as suggested earlier by dragonkeeper and opening that script directly in your MPEG-2 encoder, whichever one you plan on using. You can do the correct colorspace conversion and any other filtering you might want, in that same script.

I apologize. I skimped on the details as I thought they were irrelevant to my issue.
I'm using a DVD (specifically LG DV482) player connected to my TV which can play XviD files so the final movie is in fact encoded with XviD.
This is what I'm doing from start to finish:
Open the MJPG file in VDub, set audio to FPM, compression to Lame MP3 112 Kbps ABR (source is PCM), set video compression to XviD, about 2500 Kbps bitrate, set frame rate to decimate by 2 and finally, save the output video.
I hope now everything is clearer.

[manono]

I hope now everything is clearer.

Clearer, but you're still doing it very wrong. If making a 4:3 DVD, at playback time it gets resized to 640x480 (that's one way of looking at it, anyway). DVDs get resized at playback time based on the DAR (=Display Aspect Ratio, either 4:3 or 16:9). Unless you set a PAR in the AVI (and you're not), your AVI doesn't get resized and it remains 720x480 and people are fat. Can you understand that if it's supposed to have a 640 width, if you stretch the width out to 720 people also stretch out and become fat looking. Maybe go find something that's supposed to be round in the video, a ball, sun, moon, etc. Notice how it's not round but a slightly flattened oval.

And no, if you set the video for Direct Stream Copy, nothing changed in the video. If something changed, then you didn't use Direct Stream Copy.

[Og]

And no, if you set the video for Direct Stream Copy, nothing changed in the video. If something changed, then you didn't use Direct Stream Copy.

That is simply not true. Please, try it and tell me what happened, even if you're 100% sure nothing will.

Clearer, but you're still doing it very wrong. If making a 4:3 DVD, at playback time it gets resized to 640x480 (that's one way of looking at it, anyway). DVDs get resized at playback time based on the DAR (=Display Aspect Ratio, either 4:3 or 16:9). Unless you set a PAR in the AVI (and you're not), your AVI doesn't get resized and it remains 720x480 and people are fat. Can you understand that if it's supposed to have a 640 width, if you stretch the width out to 720 people also stretch out and become fat looking. Maybe go find something that's supposed to be round in the video, a ball, sun, moon, etc. Notice how it's not round but a slightly flattened oval.

Either I don't understand you, or you don't understand me (probably the former). I intend to get to the bottom of this, so please answer these questions:

1. Why do you keep mentioning DVD ? The source is AVI, the output is AVI, there is no DVD Video OR DVD media in the entire process so what exactly is the connection to DVD?
2. Where exactly are people/objects supposed to look "fat" ? in MPC/VLC (PC monitor) or on my TV?

BTW, thanks for all the help so far, I really do appreciate it

[manono]

1. A 720x480 DVD gets resized at playback so people get 'normal' looking again. Your 720x480 AVI doesn't get resized.
2. Where? Everywhere, player, TV everywhere. I suppose you might not notice, not if you don't have how it's really supposed to look to compare. That's why I suggested trying to find something round to check that it's not round.

Please, try it and tell me what happened, even if you're 100% sure nothing will.

I know what setting the video to Direct Stream Copy does. What changed? The file size? Maybe you decoded the audio to WAV audio and the size got larger as a result. A quick check in MediaInfo or GSpot should be able to answer that one.

[jagabo]

And no, if you set the video for Direct Stream Copy, nothing changed in the video. If something changed, then you didn't use Direct Stream Copy.

That is simply not true. Please, try it and tell me what happened, even if you're 100% sure nothing will.

VirtualDub can decimate frames if the video codec is all i-frame (MJPEG is) but the output file will be the same codec. MJPEG cannot be converted to Xvid in Direct Stream Copy mode.

[manono]

Oh yeah, it can be decimated if all I-Frames. So maybe that's what he did in which case I (and AlanHK both) have to apologize for doubting him. I apologize for contradicting you, Og.

Also, jagabo, that MJPEG video is 4:3, isn't it, so when being played it'll show people as they're 'supposed' to look, right? He should then be able to easily tell the differences by opening 2 instances of a player and comparing the same frames of both the MJPEG and the XviD.

[jagabo]

that MJPEG video is 4:3, isn't it

Given it's a "Cheap Chinese Crap™ camcorder" I don't know if it's 4:3 DAR or 3:2 DAR. It's easy enough to find out though, as you already suggested.

[Og]

VirtualDub can decimate frames if the video codec is all i-frame (MJPEG is) but the output file will be the same codec.

I did not try to decimate the M-JPEG directly, only the Xvid.

MJPEG cannot be converted to Xvid in Direct Stream Copy mode.

Yes, I am aware of that, been using VDub for many years

That's why I suggested trying to find something round to check that it's not round.

But it IS round.

What changed?

File size and FPS (Both halved), see for yourself (2 images):
https://forum.videohelp.com/images/imgfiles/a/CoHAg

in which case I (and AlanHK both) have to apologize for doubting him. I apologize for contradicting you, Og.

No apologies necessary, but you should have tried it yourself like I asked. It's a 5 second test...

He should then be able to easily tell the differences by opening 2 instances of a player and comparing the same frames of both the MJPEG and the XviD.

I already did that after your first post in this thread. I didn't notice anything different.



Here, I uploaded a short video from my camcorder, feel free to see for yourselves:
http://www.mediafire.com/?5ht7qub143kqj4z

[jagabo]

Yes, you can change the frame rate of an Xvid file with VirtualDub in Direct Stream Copy mode. What it does is throw out or duplicate entire GOPs to decrease or increase the number of frames. Which explains exactly what you saw:

a video that plays in slow motion and skips a second or two occasionally while the audio is normal.

Looking at the MJPEG video sample, the camera appears to shoot square pixel.

[manono]

Looking at the MJPEG video sample, the camera appears to shoot square pixel.

Yep, that plate (or whatever it is) is pretty good evidence of the fact. But, it really doesn't make sense to me since MJPEG is useless as a final output format. At 720x480 it seems ready-made for DVD but it can't be done without either cropping a considerable amount from the sides and resizing or adding black bars above and below and resizing. I've never in my life seen a 720x480 square pixel source.

But there's always a first time and (once again) I owe Og an apology.

[Og]

As I said: No apologies necessary.

Cheap Chinese Crap™ doesn't always make sense, but it is always dirt cheap, and that's how I like it

Again, thanks to you all.