Converting PAL DVD 25 FPS to NTSC 23.976 FPS

I am working on an Aliens project preserving the original colour and audio of the theatrical release.

I found the Aliens Special Edition THX PAL DVD at my mum’s house and I own the blu-ray. My goal is to have the DVD video synced to the blu-ray 4.1, fan-made 4ch stereo audio and subtitles.

Problems:

• DVD video is 25 FPS and the blu-ray is 23.976 FPS
• DVD audio is higher pitch
• When converting to 29.97 NTSC via ffmpeg or 23.976 NTSC with Handbrake, the runtime stays the same.

When converting from 25 FPS to 23.97 FPS, the runtime should go from 2hr 28min to 2hr 34min because PAL is sped up 4%.

I am using Mac so any solution for that would be preferable, I can use Windows as a last resort but it’s been 10 years since I used it regularly.

My eventual goal is to try to colour match the DVD to the blu-ray but I’ll settle for this for now. Thanks in advance for any help with making this a reality.

Here’s the detailed file info:

General
Complete name : Aliens (1986) [Special Edition].mkv
Format : Matroska
Format version : Version 2
File size : 5.83 GiB
Duration : 2h 28mn
Overall bit rate mode : Variable
Overall bit rate : 5 636 Kbps
Encoded date : UTC 2019-09-27 12:49:07
Writing application : MakeMKV v1.14.3 darwin(x64-release)
Writing library : libmakemkv v1.14.3 (1.3.5/1.4.7) darwin(x64-release)

Video
ID : 1
ID in the original source medium : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings : CustomMatrix / BVOP
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : M=3, N=15
Codec ID : V_MPEG2
Codec ID/Info : MPEG 1 or 2 Video
Duration : 2h 28mn
Bit rate mode : Variable
Bit rate : 5 244 Kbps
Maximum bit rate : 7 500 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.506
Time code of first frame : 00:59:58:00
Time code source : Group of pictures header
GOP, Open/Closed : Open
GOP, Open/Closed of first frame : Closed
Stream size : 5.43 GiB (93%)
Language : English
Default : No
Forced : No
Original source medium : DVD-Video

Audio
ID : 2
ID in the original source medium : 189 (0xBD)128 (0x80)
Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
Codec ID : A_AC3
Duration : 2h 28mn
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 6 channels
Channel layout : L R C LFE Ls Rs
Sampling rate : 48.0 KHz
Frame rate : 31.250 fps (1536 SPF)
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 407 MiB (7%)
Title : Surround 5.1
Language : English
Service kind : Complete Main
Default : Yes
Forced : No
Original source medium : DVD-Video

Easiest way I can think of is to rip the disc to an MKV file, then load that into mkvtoolnix and change the framerate in that to 23.976 and render out a new video-only MKV - this will only really work for the video, but it’ll actually change the frame rate the video file is played at, as opposed to Handbrake, which will try to interpolate (blend existing/create new) frames to preserve the speed and runtime of the original. Plus, mkvtoolnix won’t reencode the video, just change the frame rate flags.

Whether that will easily sync to the NTSC 4.1 once you have the file running at the right speed is a different story.

I think eac3to should be able to take the audio from your PAL video and convert it to NTSC speed (lowering the pitch to its correct…uh, pitch in the process), but I don’t know the command offhand for that and also don’t know if that’s available for Mac.

ChainsawAsh said:

Easiest way I can think of is to rip the disc to an MKV file, then load that into mkvtoolnix and change the framerate in that to 23.976 and render out a new video-only MKV - this will only really work for the video, but it’ll actually change the frame rate the video file is played at, as opposed to Handbrake, which will try to interpolate (blend existing/create new) frames to preserve the speed and runtime of the original. Plus, mkvtoolnix won’t reencode the video, just change the frame rate flags.

That worked like a charm, thank you! Last time I tried that with the audio it stuffed up the video. Thanks for the tip!

ChainsawAsh said:

Whether that will easily sync to the NTSC 4.1 once you have the file running at the right speed is a different story.

I’m gonna have to edit the special edition DVD to match the theatrical blu-ray to find out.

ChainsawAsh said:

I think eac3to should be able to take the audio from your PAL video and convert it to NTSC speed (lowering the pitch to its correct…uh, pitch in the process), but I don’t know the command offhand for that and also don’t know if that’s available for Mac.

I heard that meGUI also works for stuff like that but I don’t think I’ll need the DVD audio after all if I can get better audio from the blu-ray.

You can do it in adobe premier pretty easily.

Load the file in and click on interpret - assume frame rate 25. Premier by default is going to assume NTSC frame rates, so you’ll want to make sure it’s either detected 25fps on the source or manually set it to that.

Then change the playback rate to 96% (there is a checkbox option for audio pitch, I believe checking it maintains PAL pitch, I would only check this if your PAL source was already pitch corrected)

Then export at 23.976.

Premier is usually available for a free 30 day, full trial. If you have a good computer system you can bang this out in about 30 minutes start to finish.