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]

Originally Posted by StainlessS

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.ph...05#post1703705

Again Thanx TheSkiller for your reply