====== Video Manager Group IFO (VMGI) ======

  * [[DVD Structure]]
  * [[VMG]]

The VMGI is the primary [[IFO]] containing all the metadata about the entire DVD.  Or as I often call it, IFO zero.

Files are a normal IFO file, the first one on the disc, being ''VIDEO_TS.IFO'' and ''VIDEO_TS.BUP''.

  * [[http://stnsoft.com/DVD/ifo.html|Video Manager and Video Title Set IFO file headers]] - data in both VMG and VTS IFOs
  * [[http://stnsoft.com/DVD/ifo_vmg.html|Video Manager IFO]] - data specific **to the one** VMG IFO



==== VMG IFO Contents: libdvdread ====

See ''ifoOpenVMGI()'' in ''ifo_read.h''.

See ''vmgi_mat_t'' struct in ''ifo_types.h''.


<code>
ifo_handle_t *ifo_zero;
ifo_zero = ifoOpen(dvdread_dvd, 0);
</code>

** VMG ID **

  * Example: DVDVIDEO-VMG

<code>
char *id;
id = ifo_zero->vmgi_mat->vmg_identifier;
</code>

** Last sector of VMG set **

The last sector of the BUP.

<code>
uint32t i;
i = ifo_zero->vmgi_mat->vmg_last_sector;
</code>

** Last sector of IFO **

Current IFO?  Not sure...

<code>
uint32t i;
i = ifo_zero->vmgi_mat->vmgi_last_sector;
</code>

** Version number **

  * [[http://stnsoft.com/DVD/ifo.html#ver]]

<code>
uint8t i;
i = ifo_zero->vmgi_mat->specification_version;
</code>

** VMG category **

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vmg_category;
</code>

** Number of volumes **

Not sure if I've seen this one yet, where it is positvely set (todo: search IFOs).  It's the number of volumes for an entire set of the DVDs that this one is a part of a collection.

<code>
uint16_t i;
i = ifo_zero->vmgi_mat->vmg_nr_of_volumes
</code>

** Volume number **

<code>
uint16_t i;
i = ifo_zero->vmgi_mat->vmg_this_volume_nr;
</code>

** Disc side **

This should obviously be a 1 or a 2.

<code>
uint8t i;
i = ifo_zero->vmgi_mat->disc_side;
</code>

** Number of title sets **

Number of VTSs, aka IFOs.  **For debugging**, this number should match the actual amount of IFOs on a DVD.

<code>
uint16_t i;
i = ifo_zero->vmgi_mat->vmg_nr_of_title_sets;
</code>

** Provider ID **

Example: ''DEFENDERS_OF_THE_EARTH_V2D2A''.  Often blank.  32 characters not including a NULL terminator.

<code>
char *id;
id = ifo_zero->vmgi_mat->provider_identifier;
</code>

** VMG POS **

Dunno what this one is.  8-bytes.

<code>
uint64_t i;
i = ifo_zero->vmgi_mat->vmg_pos_code;
</code>

** Last byte of VMG IFO (IFO Zero) **

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vmgi_last_byte;
</code>

** Start address of first PGC **

First Play program chain.

  * [[http://stnsoft.com/DVD/pgc.html]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->first_play_pgc;
</code>

** Start sector of menu VOB **

Dunno what this is yet.

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vmgm_vobs;
</code>

** Sector pointer to TT_SRPT, table of titles **

  * [[http://stnsoft.com/DVD/ifo_vmg.html#tt]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->tt_srpt;
</code>

** Sector pointer to Menu Program Chain Table (VMGM_PGCI_UT) **

  * [[http://stnsoft.com/DVD/ifo_vmg.html#pgciut]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vmgm_pgci_ut;
</code>

** Sector pointer to Parental Management masks (VMG_PTL_MAIT) **

  * [[http://stnsoft.com/DVD/ifo_vmg.html#mait]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->ptl_mait;
</code>

** Sector pointer to copies of VTS audio/sub-picture attributes (VMG_VTS_ATRT) **

  * [[http://stnsoft.com/DVD/ifo_vmg.html#atrt]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vts_atrt;
</code>

** Sector pointer to VMG_TXTDT_MG **

Text data.  No idea what this one is.

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->txtdt_mgi;
</code>

** Sector pointer to menu cell address table (VMGM_C_ADT) **

  * [[http://stnsoft.com/DVD/ifo.html#c_adt]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vmgm_c_adt;
</code>

** Sector pointer to menu VOBU address map (VMGM_VOBU_ADMAP) **

  * [[http://stnsoft.com/DVD/ifo.html#vam]]

<code>
uint32_t i;
i = ifo_zero->vmgi_mat->vmgm_vobu_admap;
</code>

** Video attributes of menu VOBs (VMGM_VOBS) **

  * [[http://stnsoft.com/DVD/ifo.html#vidatt]]

<code>
video_attr_t *a;
a = ifo_zero->vmgi_mat->vmgm_video_attr;
</code>

** Number of audio streams in menu VOBs (VMGM_VOBS) **

Should be 0 or 1 (**debugging checks**).

<code>
uint8_t i;
i = ifo_zero->vmgi_mat->nr_of_vmgm_audio_streams;
</code>

** Audio attributes of menu VOBs (VMGM_VOBS) **

  * [[http://stnsoft.com/DVD/ifo.html#maudatt]]

For //channels// the most common integer value (from my findings) is 0 or 1.  Need to find out if that means integer + 1 (so, 0 = mono, 1 = stereo) or what.

<code>
audio_attr_t *a;
a = ifo_zero->vmgi_mat->vmgm_audio_attr;
</code>

** Number of subpicture streams in menu VOBs (VMGM_VOBS) **

Should be 0 or 1 (**debugging checks**).

<code>
uint8_t i;
i = ifo_zero->vmgi_mat->nr_of_vmgm_subp_streams;
</code>

** Subpicture attributes of menu VOBs (VMGM_VOBS) **

<code>
subp_attr_t *a;
a = ifo_zero->vmgi_mat->vmgm_subp_attr;
</code>