Frame size to use for editing 16:9 footage extracted from a DVD

[jason1123]

I'm trying to edit some footage from a DVD in Premiere CS4. The DVD is NTSC, 29.97 (soft telecined), and 16:9. I've read differing thoughts on this in regards to different uses for the footage, but what I'm wondering is what the maximum "real" or square pixel resolution the footage is. I can just convert my MPEG into a 23.976 fps AVI of that size and make any adjustments for an output format later. The DVD spec for NTSC says 720x480, but that's a 3:2 aspect ratio. If I open my MPEG file in VirtualDub (using DGMPGDec) and switch to 16:9 the frame is 854x480. If I play the video in Media Player Classic, its 960x540. If you crop off the black bars, its 640x360. All 16:9, but I'm not sure which to use. Is it just wasted space to edit in anything over 640x360 or is there "real" data in the MPEG file that gets thrown away unless you use a larger size?

[edDV]

16:9 DVD is 720x480 with non-square pixels. 854x480 is a hrorizontal stretch to square and a horizontal resample.

If you set a DV 720x480 (wide) project in CS4, you can edit 720x480 at native pixel size and preview correctly at 16:9. Any processing will decode MPeg2 to RGB.

[jason1123]

I guess I should've added that the reason I'm doing this is I've been trying to just edit the MPEG file in Premiere CS4 but given up on that because the audio is always a little out of sync (and only in Premiere) no matter what I do (I've run it through VideoReDo's QSF, demuxed it with different programs, patched the header to change 29.97 to 23.976, interpreted the footage in Premiere to do the same, etc.), so I was just going to go back to plain uncompressed AVIs (RGB) since I have plenty of hard drive space anyway and I won't be using more than 2 video tracks.

Aren't the "non-square" pixels in some way equivalent to square pixels that get different horizontal resamples applied to them depending on their intended output medium? Maybe they're not defined in the same way, but there must be some lower square-pixel resolution that's inferior to the potential resolution/density/dpi or whatever terms you think about it in, and some upper square-pixel resolution that's simply blowing them up artificially beyond what's really there.

[edDV]

I guess I should've added that the reason I'm doing this is I've been trying to just edit the MPEG file in Premiere CS4 but given up on that because the audio is always a little out of sync (and only in Premiere) no matter what I do (I've run it through VideoReDo's QSF, demuxed it with different programs, patched the header to change 29.97 to 23.976, interpreted the footage in Premiere to do the same, etc.), so I was just going to go back to plain uncompressed AVIs (RGB) since I have plenty of hard drive space anyway and I won't be using more than 2 video tracks.

Aren't the "non-square" pixels in some way equivalent to square pixels that get different horizontal resamples applied to them depending on their intended output medium? Maybe they're not defined in the same way, but there must be some lower square-pixel resolution that's inferior to the potential resolution/density/dpi or whatever terms you think about it in, and some upper square-pixel resolution that's simply blowing them up artificially beyond what's really there.

Not clear what you are trying to do with this DVD VOB. Natively it is 720x480 either 29.97 interlace or 23.976 progressive. Those are the only choices for 720 DVD (704 and 356 also allowed).

In its muxed VOB or demuxed MPeg2 form you can work with it without decode if you edit on I frames. If you want square pixels you must demux, decode to YCbCr or RGB and resample to 854x480. This is all destructive.

[manono]

I agree. And I think the audio out of synch issue is probably a red herring (my guess being drop frame .vs non-drop frame timing). Have you done the work and played the result to find the audio still out of synch? If the lengths of both the audio and video remain the same, there's no reason for the audio and video to get out of synch unless there's a delay involved (easily fixable).

Also, what kind of editing work are you doing? Maybe you don't need to use Premiere at all. You don't if just cutting stuff out.

[jason1123]

I'm doing a music video, which needs frame-accurate cuts to make the video match the music beats. Also, my output format will just be for the web, so I don't need to maintain the original format.

I'm using the DV - NTSC (Widescreen) preset for my Sequences. Here are the settings I've tried that seemed relevant:

Editing Mode: Desktop, DV NTSC
Timebase: 23.976, 29.97
Fields: No Fields (Progressive Scan), Lower Field First, Upper Field First
Display Format: 30fps Drop-Frame Timecode, 30fps Non-Drop-Frame Timecode, 24fps Timecode
Preview File Format: NTSC DV, Microsoft AVI

The audio shows up out of sync both when playing from the Timeline and in Export.

My MPG file is 1:50:48:28 in length (according to the DVD back cover, VideoReDo, and even Adobe Encore), but Premiere thinks its 1:28:41:03. Here's what I've tried to fix this:

1. Used Interpret Footage to change frame rate to 23.976. The video and audio were extended to 1:50:44:16, 4 seconds shorter than in the Project window, and, playing it, the audio was clearly from a much earlier time in the MPG. Also, the voices became very low pitched with that sound you hear when audio is timestretched.

2. Used DVDPatcher (set to patch the entire file) to patch the MPG to 23.976 before importing it to Premiere. That makes the audio only about 5 seconds out of sync with the video.

3. Demuxed the original MPG to M2V, which Premiere still saw as the same wrong length, but after running DVDPatcher saw it as 1:50:44:16 in length, and AC3, which Premiere saw as 1:50:49:01151 in length. So a 5 second difference between them. When I drag them onto the Timeline, the M2V really is that length, but the AC3 is actually shorter, ending at 1:50:42:09. I don't think the difference is just a delay because I tried dragging the AC3 so that its end lines up with the end of the M2V, and that makes the sync off at the beginning of the file rather than the end.

[manono]

My MPG file is 1:50:48:28 in length (according to the DVD back cover, VideoReDo, and even Adobe Encore), but Premiere thinks its 1:28:41:03.

That's obviously a 29.970 .vs 23.976fps issue (with drop-frame perhaps figuring in as well) since 1:50:48:28 is roughly 1.25 the length of 1:28:41:03. As for the rest, it's as I suspected I'm pretty sure, drop frame .vs non-drop frame (29.97 .vs 30.00fps, or 23.976 .vs 24.000fps). I don't use Premiere, but it seems to me you've set things up incorrectly. Perhaps someone familiar with the program can set you straight.

[edDV]

If your source is wide DV (29.97 720x480i) you should keep frame rate at 29.97*. This will work better for computer playback as well. Option is to bob deinterlace to 59.94 which would be even better for computer display. This is best done outside Premiere.


* unless your camcorder was shooting a 24p mode. If so, best to convert to 24p outside Premiere unless this cam was shooting 24PA.

[jason1123]

My source is a soft-telecined DVD--29.97 that's artificially created from 23.976--so 23.976 is the right Timebase for the sequence. I actually got an MPG from a different DVD to work just fine with the same settings I was using for the problematic one. From further research on the Adobe forums, it appears that Premiere sometimes just can't recognize or play MPEG files properly for varied and nuanced reasons. Its suggested to either use a plugin like Cineform or Mainconcept MPEG Pro or convert to another format. I've converted the MPG to a lossless codec in the Ut Video Codec Suite that others have had success with and it seems work well in Premiere and be in sync throughout. My file is 6 times bigger but still a lot smaller than uncompressed.