VCD-MPG on DVD - Is there an "easy" way ?

[TheLarch]

Hello all.

I have posted a question about this last week and got some interesting answers.

But I am still not able to solve my problem.

Let me explain in more detail what I want to do:

I have several movies in DivX-avi and Xvid-avi format.
Most of these have a framerate of 23,976 fps.
The audio is 44,1 or 48 KHz.

I have been very successful in converting all these movies into VCDs,
mostly thanks to the guides found here.

What I'd like to do now is to put two (or more) of these movies on a DVD-media
in a way that my set-top DVD-player will accept.
I.e. burn my VCD movies as "chapters" on DVD.

This is quite new to me, but I have understood some things by now:
1) the audio track has to be 48KHz
2) the framerate must be either 25 or 29,97 fps.

So, here is question nr 1:

Is there a (simple?) way to change the framerate of a DivX/Xvid avi file?
Or can that only be done with a VCD or SVCD file?

Anyway, I have a VCD-mpg file with the "wrong" fps:
is there no easy way of changing the framerate on it?

Is there really no small smart little program that will do the trick?

De-multiplexing the mpg file, re-encoding the video, shrinking or expanding the audio... Whoa!!
I have read the guides available on frame-rate conversion, and have tried following them, but with poor results so far.. thus my frustration

All and any suggestions are welcome

TL

[snowmoon]

DVD's will accept 23.976 mpeg-1 as a standard. You only need to convert the audio.

[snowmoon]

mpeg-2 aka SVCD you can use pulldown utility to convert a 23.976 mpeg-2 video stream to a 29.97 video stream. No encoding required.

[Baldrick]

Are you sure 23,976 fps mpeg1 is within the dvd standard? I have not found any dvd authoring tool that accepts it.

[TheLarch]

Thanks Snowmoon for your fast reply.

But as far as I have been able to see, the DVD standards for
framerate are only 25 and 29,97 fps.
(http://www.vcdhelp.com/dvd)

Actually, when I tried to author a DVD with a 23,976 fps movie
I got the message "illegal framerate" from both SpruceUP and DVDitPE.

Alternativly I sometimes got a message telling me that the DVD
I was going to burn would only work on a PC...

TL

[TheLarch]

Baldrik:

If you find dvd authoring tool that accepts 23,976 fps mpeg1,
please let me know about it

TL

[bugster]

AFAIK, 23.97fps is NOT valid for DVD. Pulldown.exe only works for mpeg-2. Therfore, to convert your 23,97fps mpeg-1 to acceptable DVD you must re-encode to 29.97fps. So you can either re-encode the mpeg1 or if you stll have the original avi, re-encode from that, to 29.97fps.

Don't worry about the playback degrading if you do this, it works exactly the same as pulldown, except the frames are actually present in the stream rather than being duplicated on playback by the decoder. It should still play smoothly.

[Baldrick]

If I had read my own guide I would have known that it didn't work... www.vcdhelp.com/vcddvdr ....

[TheLarch]

This is so much fun.

Now that we all agree about the fact that 23,976fps
is not supported by the DVD-standards, what about
giving me some suggstions as to how I can easily
convert these blessed DivX movies to fit on DVD

TL

[snowmoon]

Don't worry about the playback degrading if you do this, it works exactly the same as pulldown, except the frames are actually present in the stream rather than being duplicated on playback by the decoder. It should still play smoothly.

Not true. A 29.97 fps mpeg-1 will have duplicated frames leadding to "judder" as opposed to 23.976fps materal that will be played back with telecine or 3:2 pulldown automatically within the player.

I was able to author 23.976 with IfoEdit, but I guess it doesn't really check for compatibility yet.

[bugster]

But surely (correct me if I am wrong here) all 3:2 pulldown does is add flags that tells the player to repeat certain frames, making the actual frame output rate 29.97fps?

[snowmoon]

But surely (correct me if I am wrong here) all 3:2 pulldown does is add flags that tells the player to repeat certain frames, making the actual frame output rate 29.97fps?

It repeats fields not Frames. This has been shown to produce a much smoother effect because it tricks the brain by not showing it the exact same frame twice in a row.

[bugster]

It repeats fields not Frames. This has been shown to produce a much smoother effect because it tricks the brain by not showing it the exact same frame twice in a row.

Ok I can accept that, but how does that work with progressive material?

[snowmoon]

Telecine ( 3:2 pulldown ) is ONLY for progressive materal, so I don't understand the question.

[bugster]

Telecine ( 3:2 pulldown ) is ONLY for progressive materal, so I don't understand the question.

Ok I obviously misunderstand here. I thought the difference between a field and a frame was that a field was made up of alternating lines, 1st field was odd line, next field the even lines, and together they made up a frame. So in PAL 50 fields per second == 25 frames per second. I also thought that progressive meant no odd/even line split, just 25 frames per second where each frame contained ALL the lines. Obviously I am mistaken with this.

Could you explain, or point me to an explanation of fields vs frames and interlaced vs progressive?

Thanks

[snowmoon]

1 Frame = 2 fields

Interlaced is when the 2 fields that make up the video frame are from different moments in time

Progressive is when both fields are from the same moment in time.

When encoding progressive and interlaced also represent how the encoder treats the seperate fields. If you encoder "interlaced" it treats the odd and even lines as two different images from different moments in time.

Telecine is a method for interlacing 23.976 materal where the TV's natural interlacing is used as an advantage to prevent "judder".

[TheLarch]

Ok. Should I interpret all this as a big "No, there is no easy way" ?

TL

[snowmoon]

If you still have the original sources you can convert to MPEG-2 at either 352x240 or 352x480 and use the pulldown utility.

That way you have a true 23.976 video that has the proper flags to play at 29.97.