VOB versus IFO Full Frame Display Aspect Ratio

[StainlessS]

DVD 'Hackers' is supposed to be 2.35:1 Display Aspect Ratio according to data on back of DVD (and IMDB), and
16:9 Full Frame Display Aspect Ratio (letter-boxed).

Shows as 4:3 Full Frame Display Aspect Ratio via DGIndex whereas
MediaInfo also shows 4:3 on VOB but on the IFO file shows as 16:9.

Is there any reason why VOB data should be used rather than IFO where their two values disagree ?

Thank you in advance.

EDIT: PowerDVD plays ok at 2.35:1 in 16:9 frame (I think).

[TheSkiller]

Is there any reason why VOB data should be used rather than IFO where there two values disagree ?
Well, kind of – Pan&Scan. For anamorphic 16:9 Titlesets where the IFOs do allow Pan&Scan mode (instead of only Letterboxing) the DAR flag inside the VOBs must say 4:3 and the Sequence_Display_Extension must be present and is usually set to 540 pixels. This just means that 3/4 of the encoded 720 pixels represent the specified DAR of 4:3. Since the encoded frame is 1.33 times wider than 540 pixels (4:3) the whole encoded frame is 16:9.
That's why the DAR flag alone reports 4:3.

Have a look at the allowed display modes in the IFOs using PgcEdit or IFOedit. I bet it says Pan&Scan allowed.

[StainlessS]

Thank you O' Skillfull one.

In PowerDVD, Pan&Scan is Greyed Out, and so cannot be used.

Here output of DGIndex log file:

Stream Type: MPEG2 Program
Profile: main@main
Frame Size: 720x576
Display Size: 720x576
Aspect Ratio: 4:3 [2]
Frame Rate: 25.000000 fps
Video Type: PAL
Frame Type: Interlaced
Coding Type: B
Colorimetry: BT.470-2 B,G
Frame Structure: Frame
Field Order: Top
Coded Number: 1518
Playback Number: 1518
Frame Repeats: 0
Field Repeats: 0
VOB ID: 2
Cell ID: 1
Bitrate: 5.972 Mbps
Bitrate (Avg): 5.138 Mbps
Bitrate (Max): 6.388 Mbps
Audio Stream: 80: AC3 3/2 384
Audio Stream: 81: AC3 3/2 384
Audio Stream: 82: AC3 3/2 384
Audio Stream: 83: AC3 3/2 384
Audio Stream: 84: AC3 3/2 384
Timestamp: 0:01:00
Elapsed: 0:00:10
Remain: 0:03:24
FPS: 127.66
Info:


From VobEdit:

Byte LBA Contents Data Value Value
[Pack Header]
[0000] Pack identifier (start code) 442 [000001ba]
[0004] SCR (System clock reference) 68 0 4 4 148 173 [44 00 04 04 94 ad ]
SCR 00000146.086
[000a] Program Mux Rate: 25200 (1260000 BPS) (10080000 bps) 1 137 195 [01 89 c3 ]
[000d] Pack stuffing length: 0 248 [f8]

[Video Stream]
[000e] Video Stream start code 480 [000001e0]
[0012] Length 2028 [07ec]
[0014] PES Header data content flags 33217 [81c1]
PES scrambling control: 0
PES priority: 0
data alignment indicator: 0
copyright: 0
original or copy: 1
PTS exist?: 1
DTS exist?: 1
ESCR flag? 0
ES rate flag: 0
DSM trick mode flag: 0
additional copy info flag: 0
PES CRC flag: 0
PES extension flag: 1
[0016] PES HeaderData length 13 [0d]
[0017] PES HeaderData 49 0 3 81 129 17 0 3 53 97 30 96 232 [31 00 03 51 81 11 00 03 35 61 1e 60 e8 ]
header data details:
PTS 00043200
DTS 00039600
PES private data flag: 0
pack header field flag: 0
program packet sequence counter flag: 0
P-STD buffer flag: 1
PES externsion flag 2: 0
[0022] P-STD buffer 24808 [60e8]
P-STD buffer scale: 1024 bytes
P-STD buffer size: 232 (=237568 bytes)

[0000] MPEG Sequence Header start code 435 [000001b3]
[0004] Video attributes 755122227 [2d024033]
Video width: 720
Video height: 576
aspect ratio code: 3
16:9
frame rate code: 3
25
bit rate: 183488
VBV buffer size: 112
constrained parameters flag: 0
load intra quantiser matrix: 1
load non-intra quantiser matrix: 0

[0008] MPEG Frame 11 51 35 ...


some frame content details:

[004c] Extension start code 437 [000001b5]
[0050] Sequence_Extension 20 130 0 1 0 0 [14 82 00 01 00 00 ]
Extension ID-bits: 1
profile and level:
Escape bit: 0
Profile identification: 4
Profile: Main
Level identification: 8
Level: Main
progressive_sequence: 0
PROGRESSIVE_SEQUENCE: 0
chroma_format: 1
chroma_format: 4:2:0
horizontal size extension: 0
vertical size extension: 0
bit rate extension: 0
vbv buffer size extension: 0
low delay: 0
frame rate extension n: 0
frame rate extension d: 0

[0056] Extension start code 437 [000001b5]
[005a] Sequence_Display_Extension 35 5 5 5 11 66 [23 05 05 05 0b 42 ]
Extension ID-bits: 2
video format: 1
video format: PAL
color description flag: 1
[005b] color primaries 5 [05]
[005c] transfer characteristics 5 [05]
[005d] matrix coefficients 5 [05]
display horizontal size: 720
display vertical size: 576


In PgcEdit on IFO shows as Letterboxed with Pan & Scan tick box unticked but not greyed out.
(Dont know if I looked at wrong place in PgcEdit, not used for about 5 years)

Weird how DGIndex seems to think that it is 4:3 when clearly show 720x576 16:9 in VOB MPEG Sequence Header
and display size: 720x576 in Sequence_Display_Extension. EDIT: Although MediaInfo thought it was 4:3 also.

Anyway, no reply necessary, have decided to Throw an error alert to user that there is disagreement.
Here is reason for Thread Question:- http://forum.doom9.org/showthread.php?p=1703705#post1703705

Again Thanx TheSkiller for your reply :thanks: