Burn NTSC Film (frame rate 23.976) to DVD-VCD?

[natrap]

I'm having some trouble creating a DVD with MPEG-1 VCD files that will play on a standard DVD player - this way about 400 minutes of video can be put on one DVD. The original files I want to burn are XVID with frame rate of 23.976. I extracted the audio to a wav with VirtualDub and then used TMPGEnc to convert the video with the extracted wav to VCD NTSC Film with the audio at 48khz as required. However, when I go to add the newly created MPEG-1 files in TMPGEnc DVD Author it says it can only use files with frame rate of 29.97 or 25. I have managed to bypass the problem by simply selecting NTSC rather than NTSC Film when I convert the video in TMPGEnc wich changes the frame rate to 29.97. What I'm unsure of is whether this is detrimental to the video quality or the audio/video sync as I presume it is adding a frame roughly every four frames. I played the newly created MPEG-1 files with 29.97 frame rate and they appear to be fine but what can you tell me?

Alternatively is there a way to create a DVD with MPEG-1 files with a frame rate of 23.976. I read that Sony DVD Architect can do this so I got a hold of it but I can't seem to figure out how to make it keep the files in MPEG-1 format. If there is a way to do it - with DVD Architect or any other program - is it simply easier to change the frame rate like I described above or is it better to keep it?

[adam]

The DVD standard only supports mpeg1 at a framerate of 29.97fps or 25fps. If you want to use 23.976fps (with pulldown flags so that its played at 29.97fps) you will have to encode to mpeg2. Since your source is xvid and you have to re-encode it anyway, this would be the best method to use.

Taking 23.976fps and converting it to 29.97fps will work, but it has serious drawbacks. A telecine is performed. The progressive frames are split into fields and repeated in a set pattern to create new frames to increase the framerate to 29.97fps. Storing NTSC footage at 29.97fps is inefficient because 1) you now have 20% more frames each second which require more bitrate and 2) now your footage is interlaced which requires more bitrate and is generally more difficult to encode.

If you instead encode to 23.976fps, you avoid both of these problems. The exact same telecine process is performed during playback, but since you don't have to physically store the video in that way (29.97fps interlaced) you should get a significant increase in quality, especially at low bitrates.

You can try to just author your 23.976fps mpeg1 files anyway. If the software lets you the DVD won't be compliant and may or may not play on any given DVD player.

[natrap]

If I encode to MPEG-2 won't I only be able to store like 2-3 hours of video per DVD, rather than 6-7 hours I can store in MPEG-1? If I did decide to do this do I select DVD NTSC in TMPGEnc? It also says 29.97 fps so wouldn't it be changing the frame rate just like VCD NTSC?

[jimmalenko]

If I encode to MPEG-2 won't I only be able to store like 2-3 hours of video per DVD, rather than 6-7 hours I can store in MPEG-1? If I did decide to do this do I select DVD NTSC in TMPGEnc? It also says 29.97 fps so wouldn't it be changing the frame rate just like VCD NTSC?

Encode to MPEG-2 with exactly the same specs as you used for the MPEG-1 encode (352 X 240. 23.976fps, 48KHz audio), but make sure that you have the 3:2 pulldown flag set. To do this, go to the template settings, and change the Encode mode to "3:2 pulldown when playback".

[LeeBear]

Another advantage of using MPEG2 is you'll most likely get better quality because you can do a VBR encode with a min=0, avg=1150, max 3000 (or anything under DVD spec) so on difiicult scenes the encoder can put more bits in if needed. Much more effecient use of bits then the fixed CBR MPEG1 VCD specs even though both will take up the same amount of disc space.

-LeeBear