[vlc-devel] debugging dvd that plays in 4x3 instead of 16x9

[Shaya Potter]

following up on this, I'm pretty sure it's a bug in vlc.  the IFO file
is set to 16x9, but the VOB is set to 4x3.  Per discussion online, it
seems DVD players are supposed to follow the IFO, not the VOB

mediainfo from IFO

$ 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%)

VLC doesn't seem to respect the IFO's aspect ratio flag and is just
using the VOBs.

On Sat, Jul 31, 2021 at 10:16 PM Shaya Potter <spotter at gmail.com> wrote:
>
> so I have a DVD whose main feature is supposed to be in 16x9 but vlc
> is playing it in 4x3 on both the normal linux player and in android
> (as an aside, I couldn't figure out how to play it in android without
> turning it into an iso).
>
> It appears squashed and setting the aspect ratio manually to 16x9
> seems to make it look right.
>
> On the other hand, I played it in Kodi on android and it seemed to
> come up in 16x9 as expected (and a 4x3 extra came up as 4x3).
>
> any ideas on how to debug this?