23 fps to 30?????

[nba_bill]

How do I go about encoding a 23fps divx.avi movie I downloaded to 30 fps through TMPG Enc.?? Do I even need to convert it? I want to play it on a standalone DVD Player. Do I just load the NTSC pallette? What do I set the Source Video to in Advanced Tab--the source is 640x372?? Thanks for all the help!!!!! Bill

[willem]

I think you need a process called telecine to create a 29fps VCD from 23.976fps source. TMPGEnc can do it but I don't know how. I've never used it since I live in PAL country.

[vitualis]

Firstly, if it is truly in 23.976 fps, you could just encode it using the NTSC-FILM template in TMPGEnc. If you stand-alone player is truly compliant, you should be able to play NTSC-FILM frame rates just fine.

If you really want/need to convert to 29.97 fps, then load the NTSC template (i.e., 29.97 fps). Now, click on "Settings" and then the "Advanced" tag. Now, click on the box that says 3:2 pulldown so that it is checked.

I strongly suggest that you try NTSC-FILM VCD first as it yields much better quality.

Regards.

[nba_bill]

Thanks Michael will try that. But what do I set my Video Source Aspect Ratio at on the Advanced Tab???

[vitualis]

4:3 525 line NTSC.

I think that this should be right... Encode a short bit of film with people (so you can tell if the aspect ratio is off). Then play the short MPEG full screen (this should strech it out to 4:3 aspect ratio -- at least it does with WMP).

Regards.

[BadAsh]

I'll admit that I don't get too tied down to the technicalities of everything but I have never had a problem when following the rule of thumb given in the "Conversion" section here at VCDHelp (under the TMPGEnc guide):

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
VideoCD(PAL) if the original source in 25 fps or
VideoCD(NTSC) if the source in 29,97/30fps or
VideoCD(NTSCFilm) if the source is 23,97fps.
....
If the video is some strange fps as 60 fps or something try with either PAL or NTSCFilm and see what looks best.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>

I also use another rule of thumb... sometimes I come accross videos that are an odd 15fps. In this case I use the standard NTSC Template in TMPEGEnc because obviously 15 x 2 = 30 (29.97/30fps). You can read this rule of thumb as "convert based on math - Example: fps is 50 then encode at PAL 25fps, fps is 15 go up to NTSC 29.97/30fps". By all means try something though. Select a "Source Range" to encode and pick a template... if it doesn't work (looks stretched out, video choppy, etc) then try something else. By selecting a "Source Range" you will only have to encode a "test portion". Source Range is on the "Advanced" tab.

BTW, I have never messed with this "PullDown" feature for such conversions and have never had a problem.

[vitualis]

NTSC-FILM doesn't work on all players.

If you want to go from 23.976 --> 29.97, using the 3:2 pulldown is a must. Otherwise, you'll invariable get regular skipping.

Regards.

[BadAsh]

vitualis, since I have never used it, can you explain what the "3:2 Pulldown" is?

Thanks!

[vitualis]

I only have a superficial understanding of what this is (one of the advantages of living in a PAL country is that I NEVER have to think about this normally) but I'm sure if you search the forums, you'll find a better explanation.

3:2 pulldown creates a 29.97 fps interlaced video from a 23.976 progress source. How it does this, I'm not entirely sure but it involves the repetition of certain fields in a particular order.

The video on an NTSC DVD is often in 23.976 fps progressive video and the DVD player performs a hardware 3:2 pulldown to bump it up to 29.97 fps interlaced video.

For a SVCD, you can actually just add flags to the MPEG stream to tell the DVD player to do the 3:2 pulldown so you can just keep the video in 23.976 fps.

A standard VCD, however, doesn't support the 3:2 pulldown flags. Thus if your player doesn't support NTSC-FILM for standard VCDs, you will have to manually encode it to 29.97 fps (using the software 3:2 pulldown option in TMPGEnc). This, however, creates an interlaced video -- which doesn't encode that well in VCD MPEG-1 (as only progressive video is supported). This is why I suggest trying an NTSC-FILM VCD first before doing this step.

However, this is still preferable to not doing it (if you must do a framerate conversion).

Regards.

[BadAsh]

Thanks vitualis!

[kriskim]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2001-08-24 08:11:12, vitualis wrote:
I only have a superficial understanding of what this is (one of the advantages of living in a PAL country is that I NEVER have to think about this normally) but I'm sure if you search the forums, you'll find a better explanation.

3:2 pulldown creates a 29.97 fps interlaced video from a 23.976 progress source. How it does this, I'm not entirely sure but it involves the repetition of certain fields in a particular order.

The video on an NTSC DVD is often in 23.976 fps progressive video and the DVD player performs a hardware 3:2 pulldown to bump it up to 29.97 fps interlaced video.

For a SVCD, you can actually just add flags to the MPEG stream to tell the DVD player to do the 3:2 pulldown so you can just keep the video in 23.976 fps.

A standard VCD, however, doesn't support the 3:2 pulldown flags. Thus if your player doesn't support NTSC-FILM for standard VCDs, you will have to manually encode it to 29.97 fps (using the software 3:2 pulldown option in TMPGEnc). This, however, creates an interlaced video -- which doesn't encode that well in VCD MPEG-1 (as only progressive video is supported). This is why I suggest trying an NTSC-FILM VCD first before doing this step.

However, this is still preferable to not doing it (if you must do a framerate conversion).

Regards.

</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>
badash, if you're ripping from a dvd, it is just about 100% to be from an original 23.976 source, since movie theatre film is from there.
however, from what you described about the divx, it doesn't look to be a progressive film, but instead, oddly encoded. you can change the framerate and encode it, but you'll have to do the audio at the same time, or else you'll end up with massive a/v synch problems, as your video will become around 30% shorter (there are now 30fps instead of 23) but your audio will be the same length. if you encode vid/aud together in tmpgenc, tmpgenc will compensate for it and compress the audio accordingly.

[vitualis]

If the original DivX was 23.976 fps, it will undoubtedly have been a DVD rip itself -- i.e., it will be progressive.

The whole point of using 3:2 pulldown (remember ONLY if necessary!! -- try NTSC-FILM first) is so that A/V sync problems WON'T occur.

If you load a 23.976 fps source and use a 29.97 output framerate (without 3:2 pulldown), TMPGEnc will try to stretch the 23.976 frames into 29.97 every second. I don't know how it does it, but it doesn't do it well --> skipping. 3:2 pulldown must be used (but again, only if a framerate conversion is required at all).

DivX can be a pain so I can't promise you this for DivX, but if it were any other AVI codec (e.g., PicVideo MJPEG) that was in FILM framerate (23.976), I can guarantee that the audio in the output file will be in sync and the video will be smooth (well smooth-ish, it won't be jumpy) and be in 29.97 fps if you used 3:2 pulldown.

If you didn't, the audio will probably still be in sync, but the video will be so jumpy/skippy to be unwatchable.

Regards.