I have a DVD that is problematic (not just in MakeMKV) in that the ifo says its 16x9 (correct), but the VOBs list themselves as 4x3. Reading Doom9, it seems the DVD spec says to follow the IFO.
Kodi does (i.e. plays it in widescreen), it seems VLC and MakeMKV do not.
i.e. from mediainfo of the DVD
$ mediainfo VTS_05_0.IFO
General
Complete name : VTS_05_0.IFO
Format : DVD Video
Format profile : Program
File size : 42.0 KiB
Duration : 46 min 21 s
Overall bit rate mode : Variable
Overall bit rate : 124 b/s
Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Duration : 46 min 21 s
Bit rate mode : Variable
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 (29970/1000) FPS
Standard : NTSC
Compression mode : Lossy
<snip>
but from VOB
$ mediainfo VTS_05_1.VOB
General
Complete name : VTS_05_1.VOB
Format : MPEG-PS
File size : 1 024 MiB
Duration : 21 min 59 s
Overall bit rate mode : Variable
Overall bit rate : 6 507 kb/s
Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main at Main
Format settings : CustomMatrix / BVOP
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : M=3, N=15
Format settings, picture structure : Frame
Duration : 21 min 59 s
Bit rate mode : Variable
Bit rate : 5 993 kb/s
Maximum bit rate : 3 500 kb/s
Width : 352 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 1.184
Time code of first frame : 00:00:00:00
Time code source : Group of pictures header
GOP, Open/Closed : Closed
Stream size : 943 MiB (92%)
from display of MakeMKV
Track information
Type: Video
Codec: Mpeg2
Resolution: 720x480
Aspect ratio: 4:3
Frame rate: 29.97 (30000/1001)
and from mediainfo of produced mkv via MakeMKV
$ mediainfo title.mkv
General
Unique ID : 295133586684507535348023511269262280046 (0xDE08A945A6270904BA2DBB4DFBE8C56E)
Complete name : title.mkv
Format : Matroska
Format version : Version 2
File size : 2.01 GiB
Duration : 46 min 23 s
Overall bit rate mode : Variable
Overall bit rate : 6 188 kb/s
Encoded date : UTC 2021-08-01 07:17:23
Writing application : MakeMKV v1.16.4 linux(x64-release)
Writing library : libmakemkv v1.16.4 (1.3.10/1.5.2) x86_64-linux-gnu
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
Format settings, picture structure : Frame
Codec ID : V_MPEG2
Codec ID/Info : MPEG 1 or 2 Video
Duration : 46 min 23 s
Bit rate mode : Variable
Bit rate : 6 000 kb/s
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate mode : Constant
Frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.579
Time code of first frame : 00:00:00:00
Time code source : Group of pictures header
GOP, Open/Closed : Closed
Stream size : 1.94 GiB (97%)
Language : English
Default : No
Forced : No
Original source medium : DVD-Video
I can edit the produced MKV to be 16:9 but that's seriously annoying on a badly mastered TV series (yes, I've scripted it, but I feel sorry for those that dont know how to do it)